Office Building by Northeastern School of Architecture

FALL 2008

OFFICE BUILDING Northeastern University School of Architecture ARCH G691 Graduate Degree Project Studio

FALL 2008

OFFICE BUILDING Northeastern University School of Architecture ARCH G691 Graduate Degree Project Studio

BRENDAN CROSBY

STEVEN ORLANDO

BRIAN ELY

JASON NEVES

JASON HICKEY

JAMES SAUNDERS

LISA HOANG

SALVATORE VALENTE

MATTHEW JOHNSTON

EDGAR VELIZ

Published by Northeastern University School of Architecture 360 Huntington Ave Boston, Massachusetts 02115

Studio Research Team Brendan Crosby

- Mechanical Systems

Brian Ely

- Vertical Circulation

Jason Hickey

- Ofﬁce Layout

Lisa Hoang

- Exterior Wall Systems

Matthew Johnston

- Common Programing, Back of House

Steven Orlando

- Lighting and Book Design

No part of this publication may be used, reproduced,

Jason Neves

- Introduction and Graphic Standards

stored in a retrieval system, or transmitted, in any

James Saunders

- Common Programming, Lobbies

form or by any means, electronic, mechanical,

Salvatore Valente

- Structural Systems

photocopying, recording, or otherwise, except as

Edgar Veliz

- Ofﬁce Sociology

permitted under Section 107 or 108 of the 1976 United States Copyright Act, without the prior

Studio Lead

written permission from the authors.

John Backman Unless speciﬁcally stated otherwise all content is Special thanks to Yanni Tsipis of Colliers Meredith & Grew real Estate Consultants

property of the authors. Every reasonable attempt has been made to identify owners of copyright, photographs, diagrams and images. Errors or omissions will be corrected in subsequent editions.

This publication has been prepared as part of a ďŹ ve week graduate thesis studio assignment in the Northeastern University School of Architecture for the Fall 2008 Architecture G691 course. Other publications in this series include urban retail, hotel, and parking garage typologies, all produced by graduate students in the Northeastern University architecture program.

Introduction

Structure

6 22

2. Vertical Circulation

Mechanical Systems

Common Programming

Exterior Wall Systems

6. Lighting

7. Floorplan Configuration

114

8. Sociology

134

0. Introduction

Overview

Chapter Contents

Office buildings host many intricate systems and design strategies that become staggering

0.1 Office Types

when trying to incorporate them all at the same time in the design process. This book breaks

Type Definitions Floor Plans

down the components of the office building and presents them in a comprehensive manner in

0.2 Definitions

order to give the young professional a foothold in the understanding of such a complex build-

Typical Plan Components Area Calculations

ing. In order to expedite the learning process of office buildings, this book uses generic office

0.3 Site Considerations

floorplates and layouts to straightforwardly give the fundamental knowledge that can inform

Suburban Urban

any office building design.

0.1 Office Types

50+

0.1 Office Types Office buildings can be categorized by the following types: low rise, mid rise, and high rise. This page outlines the typical dimensional characteristics and configurations of each, 9-14’

providing a basis for preliminary planning decisions.

3 1 200’ 45’

40’ 30’ 40’

45’

200’

150’

60’

120’

30’

120’

45’

60’

150’

45’ Fig. 1

Low Rise

Mid Rise

High Rise

Gross Floor Area: 21,600sf

Gross Floor Area: 24,000sf

Gross Floor Area: 22,500sf

Net to Gross Ratio: 0.93

Net to Gross Ratio: 0.92

Net to Gross Ratio: 0.84

0.1 Office Types

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Low Rise Defined as one to three story structures mostly

found on large sites in low density suburban developments. Quite often low-rise offices are located adjacent to highways as single buildings or grouped together into office parks or campuses. Out of the three office types, low-rise are more often built to suit a single tenant. This leads to greater variation of size and configuration within

Fig. 2

this type. However, a generic floor plan can be distilled from these variations as shown in the images to the right. This type allows for the flexibility necessary for the building to operate as a

speculative development; easily adapting to single or multi-tenant uses as needed. Most low-rise office buildings are multi-core configurations with centrally located elevator banks and restrooms. Because the floorplate can often be quite large, multiple cores and stairs are needed to meet

maximum travel requirements. See 2.1 for more detail on travel distances

Fig. 3

Figures 1 through 4 show single, double and multiple tenant configurations. 1

4 Fig. 4

0.1 Office Types

Mid Rise Mid rise office buildings are the most prevalent

type, found in suburban settings and also in higher density urban areas. They are used in build-to-suit development situations, but are more often built as speculative developments with the flexibility to accommodate a wider range of tenant types and number of tenants. Because of their efficient use Fig. 5

of area and their flexibility, floorplans do not vary greatly from the floorplans shown to the left. Vertical circulation, mechanical systems, restrooms, and support spaces are centrally located in a single core.

Figures 5 through 7 show single, double and multiple tenant configurations.

2 Fig. 6

4 Fig. 7

0.1 Office Types

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High Rise Defined as thirteen to fifty or more story buildings

located in high density urban locations. Sites are generally very small with extremely high property value. The small site leaves little choice for developers but to build vertically. The height is also an economic function where developers try to attain the most amount of rentable area to make a profit and counter the cost of the property and construction. Fig. 8 As height increases there are greater demands put on the mechanical systems and vertical circulation,

thereby increasing the core size. Aside from this, the floorplan is very similar to that of the mid rise type and allow the flexibility required in what is most often speculative development. For economic reasons and site-specific zoning high rise office buildings are often mixed-use, incorporating a hotel into the upper floors, for instance, or including retail or restaurant amenities

in the lower and ground floors.

Figures 8 through 10 show single, double and multiple tenant configurations.

Fig. 9

4 Fig. 10

0.1 Office Types

0.2 Definitions The following section includes definitions for important terms used when designing office buildings. These definitions cover a range of general office building components as well as guidelines for calculating the area. An understanding of these terms and area calculations, particularly rentable area will aid the dialogue between the architect and client, and

Lateral Bracing see 1.5

allow the architect to accurately accommodate the

Restrooms see 4.4

clients needs early in the project.

Restroom Exhaust Elevator Lobby see 2.3

Plumbing Chase see 4.4

Service Elevator see 2.2-4 Vertical Risers Service Corridor see 2.3

Electrical or A/V Supply Air see 3.2-3 Egress Stairs

Mechanical Room see 3.2-3

Exhaust Air see 3.2-3 Fig. 12

Core The core is the heart of the office building, especially for high and mid-rise offices. All support systems are compactly situated in this centralized location. The image above points out the major components of the core that are discussed in more Fig. 11

detail later in the book.

0.1 Office Types

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Exterior Wall System Perimeter enclosure of the building. Comprised of glazing, window apertures, insulation, waterproofing, and other materials and systems. See chapter 5 and 6 for more detail

Fig. 13

Floorplate Refers to the shape and size of an entire floor, including vertical penetrations such as the core, columns, or partition walls. See chapters 7 and 8 for layout strategies

Fig. 14

Lease Span Generally the distance from the core to the exterior wall. In cases where the depth is measured from one exterior wall to another, or to a party wall, the lease span is half the actual distance. Typical lease

Fig. 15

spans in the United States range from 40’ to 45’.

Structural Bay Distance from one vertical structural member to the adjacent one. Spans typically range from 30’ to 45’. See 1.2-4 for more detail

Fig. 16

0.1 Office Types

Area Calculations: BOMA Efficient use of area is an important aspect in the design of office buildings and meeting the client’s needs. However, there are many different >50%

dominant portion

nuanced ways in which area is calculated where certain parties use one method and others use a different method. The method used by most developers and owners is outlined by BOMA (Building Owners and Managers Association) in “Standard Method for Measuring Floor Area In Office Buildings.” These methods are outlined and clearly diagrammed in the following pages.

>50%

However, the most current official BOMA

dominant portion

document should be used to ensure the most accurate interpretation of their methods.

Dominant Portion For the use of determining the usable or rentable space of a single office or floor of an office building, the dominant portion the exterior wall is the portion of that wall which constitutes more than

dominant portion

half of the vertical floor to ceiling dimension. The usable area is measured to the interior finished surface of the dominant portion of the exterior walls as demonstrated in the diagrams to the right and above.

dominant portion Fig. 17

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0.1 Office Types

Gross Floor Area Gross floor area is commonly used to discuss the size of a project or floorplate but is not used for renting or leasing purposes. The gross floor area is the area with the exterior finished surface of the exterior walls.

Fig. 20

Gross Measured Area Gross Measured area is the area of a floor within the interior finished surface of the dominant portion of the exterior walls.

Fig. 19

0.1 Office Types

Usable Area To interior finish surface of dominant portion of exterior wall. To interior finish surface of walls separating office from common floor area.

To centerline of partition walls. No deductions made for necessary columns and projections.

Fig. 21

Floor Usable Area Floor usable area is equal to the sum of all the usable areas of the same floor. It can also be measured as the gross measured area minus the floor common area and major vertical penetrations.

Fig. 22

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0.1 Office Types

Floor Common Area Floor common area is the area for use by all the tenants on that floor. It is the gross measured area minus the floor usable area and major vertical penetrations. The floor common area may include janitor closets, electrical closets, restrooms, mechanical rooms, public corridors and elevator lobbies.

Major Vertical Penetrations Major vertical penetrations are the penetrations between floors that are for the private use of a tenant. These may include stairs, elevator shafts, pipe shafts, mechanical shafts, and ducts and their enclosing walls.

Fig. 25

Floor Rentable (Leasable) Area Floor rentable area results from subtracting the vertical penetrations from the gross measured area. This area is also equal to the floor usable area plus the floor common area. This is a very important calculation as it allow the developer to make estimates on how much rent he or she will be receiving from the building.

Basic Rentable Area Basic rentable area is the area which can be charged to the rent of a single tenant. This calculation incorporated a portion of the common area into the usable area for one tenant. The calculation has two steps: 1. Floor rentable area / Floor usable area = r/u ratio 2. Usable area x r/u ration = Basic rentable area

Fig. 24

0.1 Office Types

0.3 Site Considerations

Suburban Site Low rise office buildings are most often the type seen in suburban sites. These are generally much larger then their urban counterparts ranging from 80,000 square feet to more than 400,000 square feet. One of the main determinants of the size of the site needed is parking requirements.

Parking Rules of Thumb Although parking requirements vary from place to place there are general rules of thumb that can be used at the conceptual planning level. See the diagrams on the left for these guidelines. Structured Parking: 3-4 cars per 1000sf of office space Surface Parking:

350-400sf per car*

Parking Strategies The most common strategy for handling parking loads on suburban sites is the surface lot. This

3-4 cars per 1000sf of office space

takes up an immense amount of space, often more

300sf per car*

area then the actual gross office area. Surface parking tends to take up an average of 75% of the total site. Another common strategy is the parking garage. These are often two to three level structures adjacent or attached to the office building. See â&#x20AC;&#x153;Parking: A Pattern Bookâ&#x20AC;? for more detail. *Note that zoning codes typically govern the minimum parking requirements. Numbers shown here are based on accomodating average office building occupant loads. Fig. 27

0.1 Office Types

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Urban Site Urban sites are generally much smaller than suburban ones. They range from 20,000 square feet to 60,000 square feet. Parking loads are also much smaller as site are often close to public

Embedded

transit. Because urban land values are so high, parking strategies try to minimize the amount of site covered solely by parking.

Parking Strategies Parking requirements in urban areas and cities vary greatly from city to city, and even from district to district within the same city. So it is hard to say here in great detail any rules of thumb or specific

Adjacent

numbers pertaining to parking space requirements. However there are several strategies that are useful to know in the conceptual planning phases of office design. Three of the most prevalent strategies are illustrated on the right. The first strategy embeds the parking garage in the middle of a block an below the office tower. It is hidden from street view and allows more active building program to line the streets. The second strategy is a simple attached parking structure adjacent to the office building. The third and most inconspicuous

Below-grade

strategy for incorporating parking is below grade. See â&#x20AC;&#x153;Parking: A Pattern Bookâ&#x20AC;? for more detail.

Fig. 28

1. Structure

Overview

Chapter Contents

Understanding the structural makeup of an office building is crucial to its efficient design.

1.1 Getting Started

While structural strategies have been refined over time to create the most efficient designs, even with a conventional plan there remains a great number of variables that will affect the cost and aesthetics of the building.

Floor Layouts Concrete vs. Steel Selecting the Structural System Tributary Area Live Loads

1.2 Steel Two Way Beam

This chapter intends to give a designer a basic understanding of the structural elements that

Pros and Cons Beam Sizing Column Sizing

compose a typical modern office building. It is meant to be a starting point for selecting a

1.3 Open Web Joist

structural system, and obtaining structural member dimensions of that system for schematic or

Pros and Cons Beam Sizing Column Sizing

preliminary design.

1.4 Two Way Concrete Flat Plate Pros and Cons Beam Sizing Column Sizing

1.5 Lateral Loads Types of Lateral Loads Rigid Perimeter Rigid Core

1.1 Getting Started

Floor Layouts

Concrete vs. Steel

When dealing with office buildings, especially

Both steel and concrete can be ideal materials for

speculative office buildings, the building is

the structure of office buildings. There are several

designed in order to provide tenants with large

factors however, which may sway a designer to

portions of column free space. This offers flexibilty

choose either material.

for any number of space-planning arraingemnts

From an economical standpoint, it is important

& easy desk and cubical placement. With this

to look at the specific local market when choos-

in mind, developers and architects have refined

ing to build with either concrete or steel. In many

the design of office buildings over time, and have

markets, steel can be cost effective because of

developed somewhat of a standard in what is the

its easy fabrication and because there are usually

ideal office plan and column layout.

numerous different contractors who are familiar

As in all structural configurations, a regularized,

and able to provide steel framing services. On the

nearly square structural system is most efficient.

other hand, in many markets, concrete costs less

When looking specifically at urban mid rises and

than steel and there may be several well quali-

high rises office buildings, most floor plans have

fied contractors able to build with concrete. When

columns spaced at 30’ intervals. A typical subur-

choosing either, one must look at both the cost of

ban low rise has a 45’-30’-45’ column spacing con-

obtaining the material in the area and the cost of

figuration. These column spacings have seemingly

labor to actually build the structure using the given

struck a balance between economic structural

material.

efficiency and the spatial qualities desired by the building’s tenants.

Looking at sustainability, each material has positives and negatives. Many raw materials from which steel is manufactured are becoming depleted. Also, it requires an embodied energy of about 19,2000 BTU/pound to produce. On the other hand, about 66 percent of all steel used in construction is able to be recycled. Concrete is the largest consumer of raw materials in the world. It has an embodied energy of 2400 BTU/pound. Concrete however, may also be composed of much recycled material. Buildings made of concrete can be more energy efficient because of its ability to serve as a thermal mass, stabilizing temperature swings.

1.1 Getting Started

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Selecting the Structural System

Member Dimensions

When selecting the structural system for an office

There are several factors that determine the sizes

building, their are a number of things a designer

of structural members. While not all of these have

must consider. First of all, the type of system will

been considered, this chapter intends to give a

determine the floor assembly thickness. This will

designer a good starting point by proving general

effect the floor to ceiling height, and the overall

dimensions of structural members. All informa-

height of the building. The floor thickness will be

tion in this chapter is roughly based on the criteria

highly visible in the facade (See chapter 5), and

described below.

effect how HVAC equipment will be located in the building (see chapter 3). Also, certain systems al-

Tributary Area

low for cantilevering while other systems are better

The tributary area of a column is the floor area that

suited for very tall structures. Based on structural

a column supports. Total tributary area is this num-

and economic efficiency, this chapter describes

ber multiplied by the number of floors a column

three common structural systems including the

supports including the roof. In a 30â&#x20AC;&#x2122;x30â&#x20AC;&#x2122; grid, as

two way steel beam system, the open web steel

in a typical office floor plan, a typical column will

joist system, and the two way concrete flat plate

have a single floor tributary area of 900 sf The total

system. This chapter also describes lateral load

tributary area is 900 sf multiplied by the number of

resistance techniques.

building stories. Perimeter columns have a smaller tributary area but generally receive greater loads because of lateral loads See Fig.1.

Live Loads Live loads include all loads imposed after construction including people and furniture. Office buildings are considered to receive light to medium loading at 30-100 psf. All of the information in this chapter will be based on these loading conditions.

Fig. 1

1.2 Steel Two Way Beam System

Two Way Steel Beam System The two way steel beam system is the most commonly used steel system for office buildings. It provides cost efficiency and can be fabricated

column

quickly. The two way steel beam system easily spans required distances for office buildings and

beam

can achieve greater heights than any other system.

girder

Pros

Cons

very long spans

considerable structural

possible

floor depth required

very strong for its

fireproofing required

weight easliy fabricated and

inefficient for

assembled

cantilevering

better suited to tall structures

steel angle

steel decking

1.2 Steel Two Way Beam System

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column concrete slab steel angle

Building Stories

steel decking

beam Fig.3

Fig.2

girder

Fig.4

Column Sizing

Span

Beam Depth

Girder Depth

Decking Depth

Total Slab Depth

10’

6”

8”

3”

8”

sizes are available with the same nominal dimen-

15’

8”

10”

n/a

8”

sion. The taller the building is , the larger the

30’

16”

20”

n/a

8”

45’

27”

30”

n/a

8”

Fig. 2 is for wide flange steel columns. Columns are listed with their nominal dimensions. Many

column dimensions will be.

Beam and Girder Sizing Fig. 4 lists dimensions for wide flange steel beams and girders. The spans listed are the most common ones found in a typical office building.

Corrugated cellular steel decking sheets with spans up to 10’ are most economical. Decking with a greater gauge may span up to 25’ .

1.3 Steel Open Web Joist System

Steel Open Web Joist System Using steel open web joists and joist girders is an economical alternative to traditional steel framing. Its members are lighter in weight and produce equivalent spans. Another notable benefit is the ability to run HVAC equipment and ducts through the joists.

Pros

Cons

HVAC equipment can

members are deeper

pass through

than traditional steel

joists

framing

costs less than tra-

inefficient for short

ditional steel framing

spans

light weight

fireproofing required and is more costly than on conventional wide flange beams

1.3 Steel Open Web Joist System

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concrete slab

Building Stories

steel decking

open web joist

joist girder

Fig.5

Fig.6

Column Sizing

tubular column

Fig 5. Is for tubular steel columns. It should be noted that most office buildings will use conventional wide flange columns and girders to sup-

Fig.7 Span

Joist Depth

tubular columns are much lighter than wide flange

10’

n/a

3”

Total Slab Depth 8”

columns, they are very limited in allowable height.

15’

n/a

8”

30’

20”

28”

n/a

8”

45’

24”

42”

n/a

8”

port the open web joists. This is because while

Tubular columns are better suited for low rise office buildings when cost and weight is a priority.

Joist Girder Depth

Decking Depth

Joist and Girder Sizing

Corrugated cellular steel decking sheets with spans up to 10’ are most

Open joist can rest on either Joist girders, a

economical. Decking with a greater gauge may span up to 25’ .

heavier version of the joist, as shown, or conventional wide flange girders.

1.4 Concrete Flat Plate System

Flat Plate Concrete System Concrete is unique because it can take the shape of its form and all structural members become a unified system. Though there are many structural approaches using concrete, the two-way flat plate system is ideal for office buildings. It provides the needed spans and allows for a thin, attractive floor slab and minimal floor to floor heights. This structural system is also very easy to cantilever.

Pros

Cons

attractive monolithic

Costly post tensioning

appearance

required for longer spans

large column sizes thin structural slabs

required for very tall structures

easily allows for cantilevers and irregular floor plans no fire proofing required

1.4 Concrete Flat Plate System

Building Stories

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concrete slab Fig.8 concrete column

Fig.10

Column Sizing Fig. 8 shows square concrete column sizes at a strength of 4000 psi for typical office building loading. For round columns add 1/3 of the dimension shown to the diameter. Rectangular column have the same area as square columns and can have

Fig.9

no dimension less than 10”. Significantly greater heights (up to 100+ stories) may be achieved using a higher strength of concrete. For a strength of 6000 psi, multiply the dimension by .8, for 8000psi x .7, for 12000psi x .60 .

Slab Depth Fig.9 provides general numbers for concrete slab thickness. For longer spans, concrete can be post tensioned, which will however add cost.

Span

Conventional Slab Depth

Post-tensioned Slab Depth

15’

5.5”

5”

30’

12”

8.5”

45’

n/a

12.5”

1.5 Lateral Loads

Lateral Loads The previous sections discussed systems for resisting gravity loads. Unlike gravity loads, lateral loads are forces that act upon a building horizontally. These forces include wind and earthquake loads. A tall building must have structural elements that counter these forces.

Rigid Perimeter One way of providing lateral resistance in tall structures is by stiffening the perimeter of the building. This can be done by using either diagonal bracing as shown in Fig. 11, moment connections or shear panels. While diagonal bracing and shear panels will cause design limitations on the buildings facade, using moment connections on steel members will add cost and time to the framing process.

Rigid core Typically, the core of an office building contains the stairs, elevators and mechanical shafts and is located in the center of the building. Because of its centralized location, the core provides an ideal location for resistance against lateral forces. The Fig.11 Rigid perimeter

Fig.12 Rigid core

core can also be stiffened with either shear panels, cross bracing or moment connections. In this condition, the core must remain consistent throughout the entire height of the building. Considerable design freedom with the buildingâ&#x20AC;&#x2122;s facade is allowed using this technique of lateral resistance. See Fig. 12.

2. Vertical Circulation

Overview

Chapter Contents

Vertical circulation is one of the first elements that is initially designed in high rise buildings.

2.1 Elevator Design Guidelines

The number of elevators needed is something that needs to be decided early on, as itâ&#x20AC;&#x2122;s very

Deciding number of elevators Code requirements for elevators and stairs

hard to change later.

2.2 Stairs Critical Dimensions Pressurization Standpipe

This chapter takes a look into the elevator and all of the design strategies that go into selecting the right elevator configuration. It will also take a quick look at stair towers and all of the critical dimensions that go into designing stairs.

2.3 Elevator Types 2.4 Elevator Layout Sectional overview Elevator lobbies

2.5 Latest in Elevator Technology Elevator Call Touch Pad

2.1 Elevator Design Guidelines

Guidelines for Elevators The first thing that should be done when designing any building that will incorporate elevators is to higher an elevator consultant. The systems are so complex that it takes someone full time to understand all the intricacies of elevators. With this said these next few sections will try to help you understand enough about elevators to be able to make educated choices on designing elevators within your office building. When determining the number of elevators for your office building, the general rule of thumb is that you need 1 elevator per 35,000 square feet of office space that the elevator serves. Also 1 service elevator per 265,000 square feet is a good starting point. The chart on the left is a

Area Above the First Floor That Elevators are Servicing Elevators Service Elevators

7E+05

7E+05 665,000

6E+05

6E+05 595,000

6E+05

5E+05 525,000

5E+05

5E+05 455,000

4E+05

4E+05 385,000

4E+05

3E+05 315,000

3E+05

2E+05 245,000

2E+05

2E+05 175,000

1E+05

1E+05 105,000

quick guide to the number of elevators in blue, and

70000

21 20 19 18 18 17 16 15 14 13 12 11 10 9 8 7 6 6 5 4 4 3 2 2 1 0

35000 35,000

Number of Elevators Needed

2.1 Elevator Design Guidelines

service elevators in orange that are needed for any given usable area. This rule of thumb falls apart in the taller of the mid rise buildings and most assuredly in high rise buildings. Otherwise your

Fig. 1

entire floorplate would quickly become covered in elevators. Other systems come in to play to reduce the overall number of elevators needed in these instances. Express elevators and local elevators is the most basic concept that is widely used in order to increase the efficiency out of the number of elevators used. Also two elevators sharing the same shaft is common to reduce the number of hoist ways needed while still having a high level of service. See 2.4 for more detail on elevator layouts and 2.3 for more detail on types of elevators

2.1 Elevator Design Guidelines

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Code for Elevators and Stairs The amount of code that governs elevators and stairs is too much to get into for this book. Entire books are devoted to the subject. We’ll take a look at the general layout of elevators and stairs in lay-

300’ max

ing them out within an office space. For elevators the general guideline for max travel distance is 150 feet. However this isn’t a code rule, it’s only a rule of thumb for designing an office space that doesn’t create a condition that is uncomfortable for the users. Also one elevator cab, 51 inches by 80 inches with a 42 inch clear opening to accommodate a stretcher must be provided

150’ max

and identified. See 2.3 for more on laying out elevators Stairs are more stringently confined by code. 2007 IBC stipulates that the max travel distance from the most remote location in the office floorplate to the

Fig. 2

1/3 total diagonal dimension of floorplate

stair is 300 feet. Additionally a user can only travel a max of 75 feet before they are given 2 choices for exiting. Also stair doors can’t be closer than 1/3rd the overall diagonal dimension of the floor plate. This is to ensure that if a fire is blocking one stairway, it won’t be blocking both stairways at the same time. There is also discussion right now that a third stair be mandatory for high rise buildings, this would be incorporated into IBC 2009. See 2.2 for more detail on stair design

Fig. 3

2.2 Stairs

Standpipe

2 Hour Rating

12”

Stair Pressurization Shaft

Same width as stair

Pressurized Stair Vestibule 25% of stair width 44” min* 1 1/2”

Tread Width + 12”

Fig. 4

Stair Dimensions

solute minimum width of any stair is 44 inches, so

stair in plan are the handrails. In office buildings

The total width of all stairs is based of the oc-

therefore in our example both stairs need to be a

the handrails need to extend 12 inches beyond

cupancy of the largest floor of the building. Once

minimum of 44 inches. The stair landing needs to

the top tread and on the bottom tread they need

this occupancy number is figured out, a factor of .3

have the same clear width as the stairs themselves

to slope for an extra tread width and then an ad-

inches per occupant is used to determine the total

and any doors opening onto the landing can only

ditional 12 inches horizontally.

minimum clear width of all stairs. For example if

interfere with the clear width by 25%. So in our ex-

the largest floor in an office building is calculated

ample of the stairs needing to be 44 inches clear,

In high rise buildings there is also the need for

to have 200 max occupants, then the total width of

then the door swing can overlap the clear path on

stairs to be pressurized in order to keep the stairs

all stairs is 60 inches. In a typical 2 stair building,

the landing by 11 inches.

smoke free in case of fire. There is a dedicated shaft connected to the stair for this purpose.

the width of each stair would be a minimum of 30 inches based on this calculation, however the ab-

The other critical dimensions when laying out a

2.2 Stairs

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Head Height Standpipe

2 Hour Rating

80” min

Continuous Handrail

11” min 12’ Max

4-7” 42” 34-38”

Spaced to not allow a 4” sphere to pass through

Stair Dimensions in Section

to be continuous and also in-between 34 and

marshal on wether they prefer the access to the

Code limits the height and width of each individual

38 inches. There needs to be a guardrail on the

Fig. 5 standpipe to be on the intermediate landings or on

tread on a stair. The tread can only be 4-7 inches

interior portion of the stair that is 42 inches high

the floor levels instead.

in height and a minimum of 11 inches in depth.

and also with intermediate bars so that a sphere of

Also the treads need to be of uniform dimension

4 inches can not pass through.

Other requirements for stairways in high rise buildings are: telephones or other two-way communica-

throughout a flight of stairs. Also a single run can’t go higher than 12 feet total before a landing is

Another requirement in high rise buildings is a

tion systems must be provided at every fifth floor

needed. Throughout the design of stairs it’s also

standpipe that is located either in the stairway or

inside the stairwell, and one stair must continue to

necessary to keep in mind that a minimum head

in a shaft next to the stairway with horizontal pipes

the roof and must be marked.

height of 80 inches is mandatory.

penetrating into the stairway itself. Discussions

The inner handrail of a typical stair tower needs

should happen between the architect with the fire

2.3 Elevator Types

Fig. 6

Fig. 7

Fig. 8

Traction

Machine-Roomless

Roped Hydraulic

The standard in high rise elevators. Operates at

The Machine for the elevator actually fits inside

No need for a well and can reach 60’.

speeds over 500 feet per minute.

the hoist way itself, eliminating the need for a large room on the roof.

Fig. 9

Fig. 10

Fig. 11

Holed Hydraulic

Telescoping Holeless Hydraulic

Holeless Hydraulic

Need for a well but allows a vertical height of 60’.

Same benefits of the holeless hydraulic with the

Hydraulic elevator without the need for a well or

added benefit of being able to reach 44’-1”

buried piping. Max height: 14’.

2.3 Elevator Types

arc G 6 9 1 ty polog y pattern b ook

1400

450

400’+

400 400

1200

1200 1200

Max Speed in Feet Per Minute

300’

300 300 250 250 200 200 150 150 100 100

44’-1”

60’

800 800

600 600 400 400 200 200

350

125

150

14’

Fig. 12

Deciding Which Elevator to Use

Your elevator consultant can also help with com-

When trying to decide which type of elevator to

plex elevator systems that are used in high rise

use, there’s a lot of factors that go into the deci-

buildings such as stacked cabs, where to elevator

sion. How high the elevator needs to reach is

cabs are physically attached and serve 2 floors

usually the first factor that goes into deciding what

at a time, or elevator systems where 2 elevators

type of elevator and it’s the easiest way to elimi-

share the same shaft with the gears of the lower

nate many of the options. Other things to consider

elevator mounted to the underside of the upper

are the environmental impacts of certain elevators

cab.

(mainly for low and mid rise hydraulic applications) the speed of the elevator, and of course, the cost. Ultimately you should consult an elevator consultant when deciding what elevator to go with, but these quick descriptions on the left and the chart on your right should help you get on your way.

Traction

Machine Roomless

Roped Hydraulic

Traction

Machine Roomless

Roped Hydraulic

Holed Hydraulic

Telescoping Holeless Hydraulic

Holeless Hydraulic

Holed Hydraulic

Telescoping Holeless Hydraulic

50 50

1000 1000

Holeless Hydraulic

Max Height in Feet

350 350

Fig. 13

2.4 Elevator Layout

2.4 Elevator Layout Diagramming Elevators in Section The diagram on the right is one of the first diagrams that should be drawn up when designing the vertical circulation of any high rise office building. Figuring out how to get the right amount of service to every floor is a hard task and looking at that in section is the best way to understand it. The blue areas indicate the levels that the elevators stop at whereas the dotted gray lines are the levels that arenâ&#x20AC;&#x2122;t served by that elevator, the solid gray boxes represent the elevator overrides and pits. This diagram will become very useful when conversing with your elevator consultant and figuring out the best ways to design your vertical circulation system as efficient as possible.

Low Rise

Fig. 14

Mid Rise

Fig. 15

High Rise

Fig. 16

The elevators are grouped in the center of the

A large central elevator lobby is the most typical

Elevators are staggered vertically with intermedi-

building in the main lobby area.

and efficient layout. In the larger of the mid rises,

ate transition floor or â&#x20AC;&#x2DC;sky lobbiesâ&#x20AC;&#x2122; denoted with the

elevators that are just used for freight become

dashed red line. There are several different strate-

common.

gies for the type of elevators used, from stacked elevators, to two elevators sharing the same shaft.

2.4 Elevator Layout

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Elevator Lobbies When laying out your elevators you want to group them together so they can share the same shaft. For the user, having all of the elevators in a row is

Bank of 4 elevators

8’ min

the easiest for them to be able to see all of them

in a single line.

at the same time when waiting for an elevator. 4 elevators is considered the largest amount that you want to have in a line with 3 being the optimum. When designing the elevator lobby, keep in mind that if you have all of your elevators in a single line, then your minimum lobby width is 8 feet, however

Fig. 19

if the elevators are opposite of each other across the lobby, then the minimum width becomes 10 feet instead. Fig. 17

Bank of 4 elevators

10’ min

High Rise Upper Level Lobbies

with 2 facing each

The top middle image is an elevator lobby at a

other.

typical upper level lobby and the bottom image is a typical ground floor lobby. In addition to elevator Fig. 20

shafts needing to be 2 hour rated, elevator lobbies above the first floor need to be 1-hour rated. Also doors into these lobbies need to be 20 minute rated. 8’ min

Bank of 2 elevators in a single line.

Fig. 21

Fig. 18

10’ min

Bank of 2 elevators with 1 facing each other. Fig. 22

2.5 Latest Technology

Fig. 24

Latest in Elevator Technology Having an elevator call touch pad instead of an 1

elevator button allows a computer system to de-

cide the most efficient elevator that the passenger

should use. It groups passengers that are going

to floors located near each other to provide a trip

Fig. 25

with the fewest stops. The diagram above shows people upon entering the lobby and proceeding to the call touch pad to enter in what floor they are going to. The computer system determines the most efficient elevator to get you there and a letter that is associated to an elevator is displayed on the screen. The diagram to the left shows the way that the system tries to group people going to similar floors to reduce the number of stops each elevator is making. They also try to reduce elevator overcrowding by trying to limit the number of passengers to 5. After 5 people have been assigned to an elevator, anymore passengers going to the same floor are assigned the next most efficient elevator. They also have a system that integrates the call touch pad with the security gate, so when you

Fig. 23

slide your security card through it knows what floor youâ&#x20AC;&#x2122;re going to and assigns you to an elevator.

3. Mechanical Systems

Overview

Chapter Contents

The functions of mechanical systems serve to create an indoor air environment free of pol-

3.1 General Design Info

lutants and to provide its occupants with a thermal comfort level suitable for each to work in.

Design Objectives Ventilation Requirements System Components & Functions

In office buildings where the life of the structure typically outlives the lease life of the tenants which occupy them, flexibility in design and approach to mechanical systems is important to allow the building to adapt to changing technology and varied usability.

3.2 Mechanical Circulation Load Distributions System Relationships Spacial Requirements

3.3 Localized Air Distribution This chapter discusses general design criteria for low, mid and high rise office building ty-

Variable Air Volume Systems Raised Floor Systems

pologies in relation to flexibility, occupant comfort, and spatial requirements. It discusses its

3.4 Heat Gain / Loss Building Envelope Overview

relevance to heat gain and loss, breaks down system components, their connections, and their individual functions to the system as a whole. The overall flexibility of a building relies largely on the application of air distribution. This chapter will break down the advantages and disadvantages of two typical air distribution systems: variable air volume distribution and raised floor systems.

In today’s world design and building professionals are responsible for thinking more environmentally aware, to build more sustainable, and to design “greener” systems. Lastly, this chapter will offer methods, tips and general insight to improving the efficiency and sustainability of office building mechanical systems.

3.5 System Sustainability Methods, Ideas, and Tips

3.1 General Design Information

Design Objectives The success of a mechanical system in an office building is directly related to its ability to meet certain design objectives. Maximization of Usable Space: Mechanical systems require a certain amount of space in a building, strategically placed and require a great deal of thought and communication between design teams especially early on in the design phases. Typically the sizes of the mechanical spaces required are directly related to the sizes and space requirements of the components of the systems which are decided by the square footage and load requirements individual for each project. See Section 3.2: Mechanical Service for typical space requirements for system components and spaces. Flexibility: There must be the ability to accommodate the needs of a variety of tenants and occupants and their changes in needs over the life of the building therefore it is strategically important to design mechanical systems/spaces accordingly. A well designed office will provide excess space for future tenant build out including extra mechanical room and shaft space. Occupant Comfort: The environment produced and regulated by your mechanical system must provide a very specific com-

Fig. 1 Temperature & Humidity Chart - The highlighted blue areaâ&#x20AC;&#x2122;s represent optimal operating temp.â&#x20AC;&#x2122;s and humidity for winter and summer months when mechanical systems are running most.

fort zone in relation to temperature and humidity needed for a building to be inhabited and to provide a gradient of change to suit individual preferences. In general a Class A office building should operate at 75 degrees DB and 50 percent RH in summer months and 72 degrees DB/25 percent RH in winter (Figure

Ventilation Rates for Office Buildings

3.1.1). Individual occupant comfort can be more efficiently achieved through the choice of your distribu-

Office areas/Public space

20cu ft/min per person

tion systems See section 3.4.

Toilet areas

15 air changes/hour

Life saftey smoke exhaust

8 air changes/hr/floor

Smoking room exhaust

20 air changes/hr

Nightime purges

0.5 air changes/hr/flr

Enclosed parking

6 air changes/hour

Other Design Criteria to be considered: -Provide office lobbies with separate VAV AHU -Empty Shaft Space should be provided for future tenant exhaust requirements. -Provide stair and elevator shafts with pressurization systems w/supply air fans located at penthouse mechanical rooms.

Fig. 2

-Parking structures to be naturally ventilated. -Ventilation Rates

3.1 General Design Information

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Mechanical System Components This section serves as a brief breakdown of

Standby Generators: provide alternate power

system components and descriptions of their func-

source that runs off fuel to power mechanical

tions.

system components in the case of electrical power outage

Chiller Plant: Produces chilled water as a cooling

Fig. 3

30’

medium, circulated by pumps throughout the build-

Boilers: Heat domestic hot water through electri-

ing. The water is used in various AHU systems

cal coil system and pump to domestic water tanks

throughout the building to cool air. Water is re-

for storage, as well as to AHU and fan coils.

8’

turned at a warmer temperature to be cooled again and recirculated. Typically housed in mechani-

Fan Coil Units (FCU): provides localized, non

cal levels or basement levels as this component

ducted heating and cooling.

requires spaces with head rooms of 16+ clear ft. Cooling Towers: Heat generated by chillers is

Fuel Storage Tanks: provide storage and supply

rejected to condenser water circuits and pumped

of fuel oils needed for system components such as

to cooling towers where outdoor air enters the sys-

generators, fans and air handling units to run.

tem, evaporates the water and carries it away from

38’

Fig. 4

15’

he building in an air stream via fans. Typically

Fig. 3

located on all size office building at roof top levels

Typical air handling unit (AHU) sized for mid to

or high-level setbacks.

high rise office building. See Section 3.2 for spacial req.’s

Air Handling Units (AHU): Centralized unit consisting of a blower, heating and cooling elements, and

Fig. 4

a humidifier. Receives cooled water from main

Typical air cooled chiller assembly sized for mid to

chillers or hot water from boilers and cools/heats

high rise office buildings

air and distributes it to different zones within the

See section 3.2 for spacial req’s.

building. Fig. 5 Stair Pressurization Fans: provide constant flow of

Roof-top cooling tower unit for high rise office

air to egress stairwells to ensure, in the case of a

buildings

fire, relatively smoke-free egress areas.

See section 3.2 for spacial req’s.

25’

40’

Fig. 5

3.2 Mechanical Circulation

3.2 Mechanical Circulation Load Distribution Mechanical equipment have stringent require-

the vertical and horizontal trade-offs have greater

ments for space which are critical to the efficiency

consequences. Tall buildings exert large hydrostat-

of space utilization and system performance,

ic pressures on water systems and must be broken

equal to the importance of programmatic require-

down and organized into pressure zones so that

ments. Typically in office buildings, mechanical

there is a pressure break in the circuit. This break

spaces and components are housed in mid-level

requires mechanical space with-in the tower. Typi-

or penthouse level spaces, designated strictly for

cally in high rise structures, mechanical levels can

mechanical use. For tall buildings there is more

be found to serve 10-15 levels in each direction

intense competition for space at the base of the

individually and require large clear heights, usually

structure because of demands of parking, lobbies,

16 + feet; therefore most mechanical levels will

loading docks and retail that is typically associ-

encompass two full floor levels.

M48-49

M34-35

ated with an office project. In very tall buildings space utilization becomes even more critical, as

M11-12

M10-11

L1-3 B1

L01

L01-02

B01-02 Fig. 6 In typical Low Rise office buildings one small roof-top Air Handling Unit (AHU) is sufficient to supply the entire building space with conditioned air.

Fig. 7 In a Mid Rise office building, depending on design preferences, either all mechanical components can be placed on the roof-top or a single penthouse level will be designated to house all system components serving the entire building.

P01-03 Fig. 8 In High Rise offices, mechanical loads are broken down into zones with intermediate mechanical spaces throughout the building. As a rule of thumb, each mechanical level typically serves from 10-12 floors in each direction.

3.2 Mechanical Circulation

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Typical Mech. Space Req. for High Rise Office Penthouse Levels

Typical Mech. Space Req. for Mid Rise Office Penthouse Levels

Air-cooled chillers

3,200 Sq. Ft.

Air-cooled chillers

2,500 Sq. Ft.

Cooling towers

7,000 Sq. Ft.

Cooling towers

3,000 Sq. Ft.

Tenant standby generators

1,000 Sq. Ft.

Tenant standby generators

1,000 Sq. Ft.

House domestic water tanks

600 Sq. Ft.

House domestic water tanks

600 Sq. Ft.

Fuel oil piping

Stair Pressurization Fans

800 Sq. Ft.

Stair Pressurization Fans

400 Sq. Ft.

Supply Ducts

500 Sq. Ft.

Mechanical fan room

Life saftey & tenant generators

800 Sq. Ft.

Life saftey & tenant generators

500 Sq. Ft.

Fuel oil storage

1,000 Sq. Ft.

Fuel oil storage

300 Sq. Ft.

Boiler & chiller plant

15,000 Sq. Ft.

Boiler Room

1,500 Sq. Ft.

Typical Floor Levels Mechanical fan room

Air Handlers Back-up Generator

Typical Floor Levels

Basement Levels

400 Sq. Ft.

Return Ducts

Basement Levels Chiller Stair Pres. Fans Exhaust Chases

Fuel Oil Piping System Components Return Air Supply Air Exhaust

Boilers

Fuel oil storage

Fig. 9 Diagrammatic section of a typical low rise office building showing mechanical components and connections

Fig. 10 Diagrammatic section of a typical mid rise office building showing mechanical components and connections

Fig. 11 Diagrammatic section of a typical high rise office building showing mechanical components and connections

3.3 Localized Air Distribution Systems

3.3 Localized Air Distribution Systems 45’

Variable Air Volume System (VAV) Typically in office building settings, the most efficient and cost effective way to distribute air is a VAV system (Variable Air Volume). These systems use an air handling unit (supply fans w/filters and cooling coils) to

3’

distribute conditioned air at pre-determined temperatures in sufficient quantity to offset heat gains See sec-

2’

tion 3.3. The space temperatures would be controlled 14’

by varying the volume flow rate of supply air by the use of VAV control dampers above the ceiling. The on-floor

9’

VAV system is a re-circulating system in which the air from the space is returned above the hung ceiling acting as a plenum. The air is then returned to the fan room at the core and back to chiller plants to be re-cooled. Fig. 12

Cooling loads distributed vary along with occupancy

Typical VAV system air distribution showing above ceiling supply and return ducts and overhead diffusers to cool office spaces.

levels and solar gain through the exterior skin. See sec-

45’

tion 6.2

Raised Floor Distribution System In response to the demand for flexibility and change in an office building, raised floors for distribution of air

3’

and cabling are another design choice that provides

4”

easy modification and relocation options after they are installed. Typically raised above the slab 12-18 inches,

14’

raised floors utilize lift-out floor modules that allow for easy cable and outlet modification. In this case owner-

9’2

occupied buildings use this system more frequent because the occupant derives most of the benefit through the buildings life. Air is supplied to the space from floor

18”

diffusers instead of overhead, while on floor handlers Fig. 13

blow air into the floor cavities via supply ducts. Warm air

Typical raised floor air distribution diagram showing under floor air supply ducts fed by a local AHU and plenum return duct back to the core. Floor swirl diffusers allow for a cleaner striation of cool air below to warmer air above.

is returned to the air handlers by way of open plenum above the hung ceiling as the cool air, diffused low, begins to heat and rise.

3.3 Localized Air Distribution Systems

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Advantages and Disadvantages of VAV vs Raised Floor

45’

VAV Advantages Centralized maintenance, quick, easy construction timeline, up front cost is cheaper than installing a raised floor.

VAV Disadvantages Less opportunity for personalized comfort zones with dampers, requires local mechanical room, even air distribution is sometimes compromised due to operating at high turn down; tends to mix supply air with return air at a higher percentage,

2’-6”

resulting in less efficiency.

Raised Floor Advantages 1’

Raised floors allow for lower life cycle costs

1’

because of their flexibility of re-configuring, rewiring and re-arranging office configurations. The

3’

3’ 2’

absence of overhead ducting in this system can

2’

allow for an increase in floor to floor height or a reduction in overall building height by close to 10 4”

percent. Comfort for occupants is increased by creating more personalized zoning options. This system also allows for a more efficient use of air as

14’ FL.FL.

1’-8

cooler air is distributed low and gradually makes

9’4 F.F.

its way to the plenum as it becomes warmer. The overall result is improved indoor air quality.

Raised Floor Disadvantages Larger up front construction costs.

9’ to F.F.

Fig. 14 - VAV

Fig. 15 - Raised Floor

3.4 Heat Gain/Loss

Building Envelope Overview Depending on the choice of building skin and the 45â&#x20AC;&#x2122;

exterior envelopes design approach, structures experience various levels of heat gain and loss that influence the design of distribution systems as well as the efficiency of the system. The greatest contributor of heat gain in an office building is usual sunlight. Solar heat gain is the percentage of heat gained through both direct sunlight and absorbed heat. The larger the percentage of heat gain in a building the more the mechanical systems will work to counter-balance, therefore engineers use a heat load calculation to determine the mechanical needs of these areas. Determining

Fig. 16

the specific heat gain for a design with an engineer

Raised Floor perimeter diffusers distribute air up across window walls

is pertinent to maximizing efficiency of mechanical system. Curtain wall systems (a typical choice for office skins) and other envelopes with large

45â&#x20AC;&#x2122;

surface areas of glass require additional mechanical design attention to counteract heat loss or gain. See chapter 5

Perimeter Diffuser Air Distribution To counteract heat gain at curtain walls or window walls, areas with high solar exposure, perimeter diffusers are used. Usually supplied by extra perimeter VAV boxes, they produce cooler and higher volumes of air typically to offset the heat being gained through the skin. This strategy is typically used in all distribution schemes including Fig. 17 Overhead VAV systems use seperate perimeter diffusers in the ceiling to distribute air down across windows.

raised floor.

3.5 System Sustainability

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Tips for Building “Greener”

The use of humidifiers in outside air streams keeps

When designing a building, base system size and

AHU coils wet. This condensate typically tends to

equipment on a long-term plan, one which has a

absorb pollutants in the ventilation air.

3.5 System Sustainability

significant amount of flexibility, not just focusing on the current building occupant’s needs and require-

Use daylight responsive lighting to reduce heat

ments.

gain from electric lights

Research systems that provide larger number of

In appropriate area, consider the use of mixed

control zones than conventional systems. Applica-

HVAC systems that can operate in tandem with

tions such as raised floors provide air distribution

natural ventilation. In certain weather conditions

on a wider and more individual basis which allows

the system can be de-activated and operable win-

more occupants to have control over their spaces

dows can perform the cooling and drying functions

environment.

of the mechanical systems.

Consider carefully factors that influence comfort

Energy Recovery Ventilation

see section 3.1. Consider operating spaces at

To reduce the load on primary air handling sys-

lower relative humidity during the cooling season

tems that take on the task of conditioning various

to widen the dry bulb temperature comfort band

levels of outdoor ventilation air, outdoor units that

See operating temperature chart in section 3.1.

employ pre-conditioning strategies are an efficient consideration. These recovery units moderate

Greater comfort can result from improved wall

temperature and humidity content of outdoor air

insulation or high performance glass systems (See

coming into the building and pre-condition it so to

chapter 6 for information on wall system options for

allow for the zone AHU’s to concentrate on trim

office buildings). The building envelope alone can

control rather than having to take on the much

have huge effects on how well or how sustainable

larger load variations that are imposed by outdoor

your mechanical systems can operate. Also using

ventilation air. These units will reduce demands

solar screening or shades can drastically ease the

on heating & cooling equipment and result in cost

strain on a systems typical load requirements.

savings with a short payback period.

- Provide heat exchangers within the toilet exhaust air to reduce ventilation air pre-heating requirements.

Fig. 18 Building energy disbursement breakdown highlighting the large percentage (39% of total buiding energy) used on mechanical systems

4. Common Program

Overview

Chapter Contents

Common programming and back of house spaces provide the lifeblood of any office build-

4.1 Front of House

ing. Some of them tend to be forgotten in the initial design process which can become very

Lobby Information Vestibule Requirements Security types

detrimental to the design of the building later on. Having a firm grasp of all of the common programs early on in the design process can be very beneficial to the overall design of the building.

4.2 Cafeteria Types of Spaces Location Suggestions Requirements

4.3 Back of House This chapter examines the different types of spaces that are typically associated with all office

Waste Removal Ramp Requirements

buildings. We will gain an insight of these spaces through a better understanding of the code

4.4 Restrooms Requirements

requirements and minimum space requirements. Diagrams and equations will be shown to illustrate the main points and also additional possibilities.

4.5 Ground Level Leasable Types of Leasors Requirements / Considerations

4.1 Front of House

Door types

can be adjusted to allow for higher rates of traffic,

Single doors are perfect for slower pedestrian traf-

open/close responses and verification setting. The

Lobbies

fic. There is the option to use an automatic single

gate can be left open to allow maximum flow and

The lobby is the first point of which individuals will

door which would allow the door to remain open

only close when an individual can not be identified

interact with the building. The lobby has multiple

longer, allowing for a slightly higher flow of traffic.

or set to open at a certain speed to increase or

functions; to advertise for the offices of the build-

Double doors; allow for varying traffic levels of me-

decrease traffic flow

ing, create an identity, serve as a security check-

dium to high. The option of automatic doors would

point. The lobby is the home for the Concierge,

increase the rate of traffic allowing for a higher

Guards, Speed gates, and seating area. The

density of individuals as well as any individual not

Concierge is there to provide information about

able to use their hands.

the building, what floors office or individuals can

Revolving doors are able to control the climate and

be found on and as a check in point. The guards

also the individual flow of traffic in places where

are there to verify those that have passes visually.

security is an issue. These doors will slow a

Speed gates are used to verify an individual’s ID

higher flow of traffic so that guards or speed gates

quickly and accurately. They are typically used

or not overwhelmed. Operation during emergen-

more in Urban High rises and some Urban Mid ris-

cies needs to be considered due to this slower

es due to the larger volumes of individuals. Sub-

flow. Solutions vary from double doors located

urban may utilize them if there is a large enough

near the revolving doors or collapsible doors with

number of employees. The security level can be

in the revolving door assembly.

adjusted to allow for differing rates of traffic.

Security Vestibule

A concierge and a guard are similar in purpose

A vestibule, the space separating the exterior

but different in use. Guards are serve as a visual

of the building and the lobby, is an efficient way

security check point by verifying an individuals

to control the climate with in the office and also

identity. Concierges serve not only as security

control traffic flow. A vestibule has to adhere to

but also information. They can inform individuals

specific ADA requirements. The minimum size

in the offices of a clients arrival or direct a client

that a vestibule can be is 44” wide x 72”, in the

a specified location. The number of occupants

direction of travel, and the ceiling must be 20” or

should determine the use of one or both of these.

more above the doors.

Speed gates are a more efficient and accurate way to verify the identity of individual. Varying settings

4.1 Front of House

arc G 6 9 1 ty polog y pattern b ook

Elevators to offices above

Ground level Offices

Security/Concierge

Visual Security Verification

Figure 1 Suburban Office Lobby

ents with information and check in. Offices are

This is a partial plan diagram showing the basic

typically located on the ground floor and may have

implementation of requirements in a Suburban

little separation from the lobby space.

office building lobby. The use of Speed gates may not be necessary depending on the size of the office and number of employeeâ&#x20AC;&#x2122;s. A concierge would serve as the security barrier and provide cli-

4.1 Front of House

Elevators to offices above

Speed Gates

Security/Concierge

Visual Security Verification

Fig. 2 Urban Mid Rise Office Lobby

Fig. 3 Urban High Rise Office Lobby

Depicted above is a partial plan of a Urban Mid rise

Depicted above is a partial plan diagram of a

office lobby. The need for security is greater

Urban High rise office lobby. The need for security

because of the number of employee’s and the abil-

is greater because of the volume of employee’s

ity of anyone to enter the building. The use of

and the use of more security guards and speed

speed gates may be necessary based on the num-

gates is necessary to verify employee’s quickly and

ber of employee’s and level of security required.

accurately. Rest rooms or Locker rooms maybe

Locker rooms or rest rooms may be required for

required for guards or by leasable occupants.

guards or by the occupants of possible leasable space.

4.1 Front of House

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Possible locations for sensors.

Typical elevation of a speed gate. The doors slide into the base allowing individuals access.

48” 36”

7’

Elevation of Revolving door. 11”

20”

11”

Fig. 6 Elevation of Revolving Door

Fig. 4 Elevation of Speed Gate

Interior

11”

Diagram of a revolving door in a regular use. Inside Dimension 6’ min

Typical plan diagram showing the possible locations of sensors and the movement of the gates 60”

into the consoles. Exterior Possible locations for sensors. Interior Emergency Situation Diagram of a collapsed revolving door during a fire alarm emergency. Two of the doors will fold

Fig. 5 Plan of Speed Gate

towards the exterior of the building.

Exterior Fig. 7 & 8 Revolving Door/Emergency Revolving

4.2 Cafeteria

terfering with anyone else entering. The first thing

Locker Rooms and Cleaning

to determine is the number of individuals that will

The locker rooms are required for the staff to

Cafeteria’s may be required in low rise offices

utilize the cafeteria. Once determined, divided the

change and prepare for their shifts. The clean-

and Urban High rises. Low rise office buildings

total number of individuals by the number of shifts

ing station should be located close to the kitchen

may not be located close to other food services,

for serving and then multiple by ten. Ten is the av-

and dining area so that clean plates and utensils

which would mean that employee’s might have to

erage square foot of space that an individual takes

can be transferred efficiently. These should fit in

drive during their lunch breaks to get food, if they

up. All of the other spaces will be determined from

the same amount of space as the storage and the

do not bring their own. Their use in Urban high

this space.

same equation can be used.

rise offices is based on the time it would take for SA

an employee to leave and return. A second factor is the volume of employee’s that leave during the same time, as this would affect all employee’s that

Total to be served

x 10

Shifts

Kitchen

efficient use of the employers and employee’s

The kitchen serves as a transition space as well

time.

as food preparation. An individual should have to pass through the kitchen to and from the loading

Cafeteria’s have a large range of spaces that need

dock. In this way, food can be easily accessible,

to be accounted for. Spaces include; Kitchen, Din-

as well as removed from the kitchen and cleaning

ing area, Service Area, Storage and Locker room

stations efficiently. The kitchen is should be ap-

for staff. Each category has their own set required

proximately one half the size of the dining space.

spaces with in them. The Kitchen requires cold

food preparation, range/grill, vegetable station,

SA 2

both cold and dry, should be close to the kitchen

Storage

and loading dock for quick storing and preparing

The storage should be approximately one fourth of

of food. The Service area is the space between

the space of the seating area. This is total space

the Kitchen and the Dining or Seating Area where

for storage, so dry and cold split this space.

individuals arrive and get food. The flow of traffic

through the cafeteria should not be hindered. An

individual should be able to enter, get food, seat and eat, return tray and plates and exit without in-

point and may need to be adjusted to accommodate specified appliances, or ADA requirements.

leave during that time. Cafeteria’s allow for a more

bakeshop, meat station and cleaning. Storage,

These spaces are just to give a preliminary starting

= SA 4

4.2 Cafeteria

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Locker rooms

Kitchen: allow for meat prep, vegetable prep, cold prep, range/grill, bakeshop and service line Exit to loading dock

Storage areas: Cold and dry.

Cleaning Station and Office

Dining Area Arrows represent the flow of traffic. Traffic should move in one general direction and should not impede any other traffic. Trash collection

Fig. 9 Required Cafeteria spaces and relative sizes

Kitchen Dining Area

Storage cleaning Lockers

Fig.10 Relative comparison of Space Requirements

4.3 Back of House

4.3 Back of House Several different aspects occur as a part of the back of house or support system within an office environment. The loading dock, and surrounding functions, account for most of this category, Several different layers are included when addressing the design of back of house programming. From an organizational standpoint, the juxtaposition of other back of house elements to the loading dock is the most logical. All of these features of an office building are not what the typical employee or visitor wants to have noticeable, so often times, these elements are shifted to the back or basement levels of the building. All of these aspects may have some involvement with large truck access, for delivery or shipping purposes, waste pick-up, or building and employee safety and security. Therefore it makes sense that all of these elements are located within the vicinity of the loading dock.

Criteria for Office Loading Docks Low Rise Mid-Rise x x

Dock Master's Office Central Mail Room Receiving Room Mail Room Storage Sorting Room Screening Room Explosive Anti-Room Tenant Pick-up Security Truck Checkpoint at entrance Security offices Maintenance Offices Machine Shops and Storages Building Engineers Waste Management Recycling Dumpsters Trash Dumpsters Compactors

x x x

High-Rise x

x x x x \ x

x x x x x x

\ x

x x

1 1

1 1 1+ 1+ x x 1 cu. Yd. of waste per 10,000 sq. ft. of office space Additional dumpsters may be required for leasable space on first floor. Restaurants and/or retail.

Restrooms

Occupancy of a loading dock is 1 person for every 300 square feet 1 toilet per sex will be required for anything less

4.3 Back of House

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Loading docks can be tricky when deciding on dimensions and locations. There is a lot to think about, and more often then not is approached as a case by case basis. There is no industry standard for how many bays are required for a buildings loading dock, there are only guidelines that should be explored when approached with the task of implementing one, and a lot of this has to do with the types of trucks that will be visiting the dock. Low rise, suburban, office buildings are the easiest to accommodate as there is not much in the way of space requirements. As long as it’s taken into account the maneuverability and size of a full 18 wheel tractor trailer, externally, there is not much more to cover. What does have to be considered though is a landing zone for the trailer. This zone should be made of a harder substance, so that the trailer does not sink into asphalt on a hot summer’s day. This zone can be calculated by taking the longest truck accessing the yard and subtracting 7’ from that. As well, an apron space is required, which is twice the size of a truck plus 10’ to account for the turning and reversing capabilities that these large vehicles lack. Commonalities can begin to be shown between low, mid and high rise offices at the actual dock. Docks should be designed to align with the height of the bed of a delivery truck. However, there are several different types of truck that vary in height. Commonly average dock heights are from 48” to 52”, and other variations can be accommodated by the use of dock levelers.

60° Turn 24’6” Wide Road

30° Turn 16’6” Wide Road

The Loading Dock 114”

96”-108” 90° Turn 27’ Wide Road

varies

48”-52” 120° Turn 27’ Wide Road

Outside Turning Radius 96”-102”

Inside Turning Radius 180° Turn 33’ Wide Road

96”-108” For the mid rise and the high rise office building the design may get a little more challenging. With these two options the loading dock may have to be located within the foot print of the building as there may not be enough space around the building to accommodate truck access. When the loading dock is brought within the building, more has to be identified in the terms of security. First, the area has to be blast proofed and second is how the dock is accessed, through ramps and security. Depending on extraneous services may depict how many docking bays there are in general. The offices alone may need a couple, but an extra service such as retail, or restaurant may want there own docking bay to accept their own deliveries.

150° Turn 35’ Wide Road

Minimum Road Width Requirements for truck turning purposes

Landing Strip Truck Length - 7’

Apron space = truck lengthx2 + 10’

4.3 Back of House

Approaching a Loading Dock

Approach

Loading docks are used several times everyday. How these area are accessed and kept secure is the main consideration. Low rise office buildings, generally don’t require strict security checkpoints on the approach to the building, and in most cases they are accessed by a solitary access road that brings the vehicles around to the back of the building to keep them out of site of the building’s daily users. Mid rise and high rise office buildings approach the concept of the loading dock very differently where they bring the traffic into and beneath the building. This accomplishes the same task of getting the trucks out of the sight of the buildings daily users, while throwing in other design chal-

Low Rise Mid Rise High Rise

Access Road At grade

Ramped access below grade Land Usage

Within Building Footprint Waiting Area

Security Checkpoint at entrance

Inspection Pullover Area

40’ Recommended slope of an access ramp to prevent runaway trucks.

20%

8’

15%

6’

10%

4’

2’

lenges. With the dock within the building footprint, considerations of possible threats have to be taken into account. At building entrances often times, a pull off area will be designed into the access road to allow for safety and security officials to inspect vehicles going to the loading dock. Other factors in accessing mid and high rise office loading docks include the grade of the ramp getting down to the loading dock. A dock ramp cannot be too steep for the fear of the runaway truck. It is recommended that a ramp should be between 10 and 15 % grade.

4.3 Back of House

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Waste Removal

Relative Programming

Other uses for the loading dock are also found in the waste collection and removal services. An office typically creates a total of 1 cubic yard of waste for every 10,000 square feet of usable space. Therefore, the larger the building, options arise in using up more space with more dumpsters, or using the means of compactors which can reduce the volume in a ratio of 4 or 5 to 1. Low rise offices will generally contain two dumpsters on site. Like the loading dock they would generally be pushed to the back of the building accessed by the same road that accesses the loading dock. If the lot does not allow for this, masking the appearance of the dumpsters is another option by providing an enclosed dumpster cage dressed

Around the loading dock other integral office support programming resides. For the dock itself, a dock master needs an office where the schedules can be organized to attempt to avoid an overcrowded dock. Also, as the dock is where the daily mail generally passes through, a central mail room is required in this area. Here we may see a difference from low rise offices to mid and high rise offices where security doesn’t matter so much. In low rise, all that may exist is the receiving and shipping room and the sorting room, along with a tenant pick up space. In the mid and high rise typologies, this space may also include a screening room for potential life threatening packages, explosive and chemical based. This is added se-

with excessive landscaping. Providing two 10 yard dumpsters, at 12’x8’x4’, unless otherwise specified, is the most logical explanation for this type, where one dumpster would be used for waste and the other for recycling. In mid and high rise, once again, the dumpsters are brought into the building generally at the same level as the loading dock. Space may begin to get a little bit more tricky as the building gets larger. In the mid rise an additional dumpster for more waste could be acceptable, but it may also be time to start looking at compactors, especially for the high rise, This minimizes the amount of space that the waste takes up and as well minimizes the amount of floor space that the dumpsters occupy. Similar to the amount of docking bays required, extra dumpsters may be required if extra program is included in the building design.

curity program that otherwise may not be deemed necessary. As well, the mail room, and the bay itself need storage capacity to hold shipments that are being processed for acceptance or for delivery, the mail room especially Along with these issues, there is also a building maintenance crew that needs space to complete their work, that doesn’t interfere with the general function of the offices.

4.4 Restrooms

Overview All office environments require the functions of rest rooms within the design of the building. Low, mid and high rise office buildings all require adequate rest room functions. This means that the design has to comply with state and local codes and the Americanâ&#x20AC;&#x2122;s with Disabilities Act (ADA) requirements, as well as expressing interest in aesthetic quality and functionality. Knowing these requirements and having a basic knowledge of installation requirements can prevent redesigning a layout or having casework that cannot be installed properly due to a disregard for fixture layout. Redesigns can become costly and unless the architect pays particular attention to wall types and chase dimensions to accommodate piping and supports the architect will need to readjust the spaces to meet certain code requirements in space allocation. In general, the rest rooms shall be located towards the center of the building, within the boundaries of what is the core. This is the nearest point of access for all tenants single or multi. In the case of multi tenancy the rest rooms become a public facility, unless a tenant to occupy the space requests a private facility of, which is between the architect, developer and tenants discretion.

4.4 Restrooms

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Rest Room Fixtures Rest room design for an office environment requires several different acknowledgments by the architect. One needs to know the basic principles behind the plumbing and bracket supports for the various fixtures involved in a rest room layout. There are many different types of fixtures from wall mounted toilets and urinals to the floor mounted version of the same. As well, sinks come in various shapes, sizes and materials from wall mounted to counter-tops; porcelain to stainless steel. The major factors that the architect has to worry about are aesthetics, functionality, and the product installation process. Aesthetically there are a number of choices that the architect can choose. Products are so varied that architects have innumerous possibilities, when it comes to colors, finishes, and shapes, even as far as themes for fixtures, faucets and trim. Functionality of the fixtures goes to how the facilities are used, and how the fixtures can be selected to accommodate the users more efficiently, including handicapped access. Installation and fixture types are the most important aspect of the plumbing design. In multi-story office buildings, wall hung fixtures are more logical as they provide better sanitation. This also means that space has to be accounted for within the chase wall for a bracket system that will support the fixtures. As there are many products available, the chase dimension cannot be assumed. This dimension will have to be determined after products have been selected, based on the manufacturers recommendation. To the right are the minimum requirements for chase wall depths.

6” min 12” min*

14” min*

16” min*

* Note: Add 2” for 5”-6” waste stacks

6” min

12” min

4.4 Restrooms

Rest Room Layout 7’ min

18” min

5’

5’ min

2’-8” 5’

5’ 16” min

14” min

Minimum Toilet Facilities Water Closets Female Male 1/20

Lavatories

Urinals

each sex

33%

1/50

1/25

Example 30000 sq. ft. floor plate 1 person/100 sq. ft. 150 Male

= 300 people

@ 1/25 = 4 toilets and 2 urinals

150 Female @ 1/20

= 8 toilets

Lavatories

= 3 each

A lot has to be considered when designing and laying out a rest room within an office environment. After the design of the building is determined, then the core layouts can be deciphered. Rest rooms generally are considered part of the core as this is the central location easily accessible by all. The size of the rest room is to be determined by the overall square footage of the building, and the occupancy rating of the building. For an office the occupancy rating is 1 person for every 100 square feet. Of the result number this is divided in half for men and women. For every 25 males and 20 females a separate water closet is required. The men’s rest room, has the exception with that 33 % of the water closets are required to be urinals. Lavatories, are also required at 1 for every 50 people, male and female. These are considered minimum requirements, so having more is not necessarily bad. Cost and space ultimately limit this number to the minimum, but this should not be held as a design restraint. Other functions incorporated with the rest room core include a water fountain, and a janitor’s closet with mop sink. As well, as the dimensions discussed in the previous section, other dimensions have to be considered for comfort purposes as well as handicapped accessibility. A double entry door is recommended for privacy with minimum dimensions as noted in the drawing on the left, along with the minimum dimensions of a single stall, that allow for comfort entering and using the facilities. Along with this can be addressed the handicapped accessibility requirements.

4.4 Restrooms

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ADA Compliance In accordance with the American’s with Disabilities Act, an office environment requires that at least one stall, male and female, be handicapped acces-

32” min

sible. At least one lavatory will need to meet these requirements, too. The code is regulated so that a person in a wheel chair can be granted the same

4” max 40” max

18” 56” min 42” min

34” max

amenities as everyone else.

29” min

Handicapped citizens deserve the same rights as everyone else. To not include them would be dis-

27” min

12” max

criminatory, and illegal, for that matter. The images

9” min

max 6”

min 8” 6” max 17” min

to the right give a brief overview of what is required for ADA design in a typical office setting.

17”-19” 36” min

6” max

36” max

33”-36”

27” min 9” min min 8”

6” max

48” min 12” max 36” max

40” min

17”-19”

toilet paper

33”-36”

30” min 17”-19” 19” min

24” max

4.5 Leasable

4.5 Ground Level Leasable Urban Mid-rise and Urban High rise have the

Kitchen Exhaust

Access to Loading Dock

Direct Daylight

Ventilation/Cooling

High Fire Proection

Restaurant

Light Food

the large number of groups that can occupy these spaces and the different requirements that they each require. The common uses that can occupy these spaces can range from: Retail, Light food, Restaurant, and Health Club. Each will require a unique set of design and code requirements that will need to be addressed. Spaces that require exhaust systems and HVAC systems can be problematic because of the need for venting. One solution is to place these spaces close to the core. This will allow you to combine the mechanical spaces for the building and run the shafts up through the whole building. Issues may arise because of the need for separate ventilation systems and therefore more space occupied on the above floors. The second solution is to vent through the side of the building. This will require the use of separate fans and may take up leasable space at ground level if they can not be mounted on the ceiling. Another issue of this method is where it is venting, as it may affect the surrounding buildings or spaces. Each of these consideration require careful planning and you may need to consult with a consultant about specific issues.

Street Visibility

Kitchen

level. This is not an easy thing to plan for due to

Noise Barrier

ability to have leasable space on the ground floor

Retail

Health Club

4.5 Leasable

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There are usually multiple spaces that can be

Urban High rise also have the possibility of Leas-

gained in an Urban Mid-Rise building. The high-

able space on the ground floor. The highlight

lighted section show two spaces; the left space

space is approximately 10,600 sq ft.

is approximately 9,000 sq ft and the space on the right is approximately 11,000 sq ft.

4.5 Leasable

The restaurant will require access to the loading dock for shipments and waste removal. The kitchen should be located near the core of the building so that any kitchen exhausts can go up through the core without needing to be re-routed or interrupt any office layouts above. The same equations for sizes for cafeteria still relates to these spaces. Retail Space

Storage

Kitchen Access to Loading area and Dumpsters Cleaning Area Office

Employee Lockers / Rest rooms

Dining Area Public Rest rooms

Restaurant and Retail setup

5. Exterior Wall System

Overview

Chapter Contents

There are many available systems to choose from for a buildingâ&#x20AC;&#x2122;s exterior walls. In this

5.1 Exterior Wall Systems

chapter, we will be looking at typical exterior wall systems that are used in office building.

Curtain Wall System Stud Backed Wall System Precast Concrete Wall System

Each has implications in areas such as cost, time of erection, field work, efficiency, quality of work, or the complexity of assembly. This chapter will survey the different types of exterior wall systems and provide information on which is the most efficient system to use for low, mid, and high-rise office buildings. It will also provide a fundamental understanding of the process of exterior wall construction as a basis for design decisions. Below is a organizational chart outlining the chapter and the relationships between these various wall systems.

5.2 Curtain Wall System Design 5.3 Stud Backed Wall System 5.4 Precast Concrete Panel System 5.5 Window Systems Window Wall System Curtain Wall System Storefront System

5.6 Window Appearance Exterior Wall Systems

Window Systems

Window Appearance

Stick-Built Curtain Wall

Unitized Curtain Wall

Curtain Wall System

Punched Window

Stud-Backed Wall System

Precast Concrete Panel

Window Wall System

Storefront System

Ribbon Window

Storefront Window

Ribbon Window Storefront Window

5.7 Double Skin Facade

5.1 Exterior Wall Systems

5.1 Exterior Wall System

Curtain Wall System Rigid Insulation Light Gauge Metal

Window Wall System

Metal Stud Backed System

Precast Concrete Wall

(may also be cmu wall)

Spray Insulation

Exterior sheathing

Light Gauge Metal

Air/Moisture Barrier Membrane Rigid insulation 2â&#x20AC;? Min. Air Space Exterior Finish

Curtain Wall System

Stick-Built Stud-Backed Wall System with Punched or Ribbon Windows

Precast Concrete Panel Wall System

A curtain wall is defined as thin, usually aluminumframed wall, containing in-fills of glass, metal

(may also be cmu wall)

structurally adequate to resist lateral forces while

panels, or thin stone. The framing is attached to

A stick built stud backed wall system can have

spanning between floors to between columns.

the building structure and does not carry the floor

many exterior cladding. It is erected on site by mul-

It resistance to tornado/hurricane damage; fire,

or roof loads of the building. The wind and gravity

tiple specialized teams. Studs are framed between

termite, and dry-rot.

loads of the curtain wall are transferred to the

building structure. It requires minimal hoisting time.

building structure, typically at the floor line.

Minor imperfection can be made, and transportation costs are minimized. Stick built construction is the most affected by weather conditions at the site and requires scaffolding to apply the finish.

A precast concrete panels are durable and

5.1 Exterior Wall Systems

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Cost

Time of

Stick Curtain Wall

Unitized Curtain Wall

Stud-Backed Wall

Precast Concrete Panel

Cost effective for smaller size or

More cost effective for larger

Costs are lowest for low-rise

Costs depends on number of

low and mid-rise building.

size or high-rise building.

building.

picks for low and mid-rise building

Long time to assemble on-site.

Short time to assemble on-site.

Long time to assemble on-site.

Short time to assemble on-site.

Single specialized team for in-

Multiple specialized team for

Two specialized team for instal-

stallation. they are erected piece

stallation. Each unit is connected

installation. One team needs to

lation. Only the precaster and

by piece on-site.

to form the faรงade.

finish until the next team installs.

insulator.

Single system controls thermal

Multiple system controls the

Requires less insulation for

expansion and contraction; seis-

efficiency of the building. Effi-

energy.

mic motion; building sway and

ciency depends on the quality of

movement; water diversion; and

the material chosen and details

thermal efficiency.

done by the architect.

Quality control can be strictly

Corrode when exposed to

Quality control are strictly moni-

monitored in the factory.

continuous moisture, deflect

tored by fabricators specializing

more than masonry, and act as a

in this type of construction.

Erection Field Work

Efficiency

Quality Control Presents some quality control issues. because components are erected piece by piece.

thermal bridges conducting heat to or from the exterior. Assembly 1. Anchors

1. Anchor

1. Metal Stud

1. Anchor

2. Mullion

2. Pre-Assembled

2. Exterior Sheathing

2. Precast Concrete

3. Horizontal rail

3. Rigid Insulation

3. Sprayed Insulation

4. Spandrel Panel

3. Insulation as required

4. Adhered Membrane

4. Light Gauge Metal Interior

5. Horizontal Rail

4. Light Gauge Metal Interior

5. Air Space

6. Vision Glass

Frame Unit

Finish

6. Flashing

7. Interior Mullion Trim

7. Exterior Wall

8. Insulation as required

8. Window

9. Light Gauge Metal Interior

9. Interior Finish

Finish

5.2 Curtain Wall System Design

Spandrel Glass

Shadow Box

Vision Glass

Cost: Lowest

Cost: Medium

Cost: Most

Aesthetic: Strong

Aesthetic: Less Strong

Aesthetic: Flexible

Horizontal Band

Efficiency: Require

Efficiency: Good Thermal

Efficiency: Bad Moisture

Lower U-Value glass for

Insulation

Control

better insulation

5.2 Curtain Wall System Design

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What can go wrong Curtain wall systems range from manufacturerâ&#x20AC;&#x2122;s standard catalog systems to specialized custom walls. Custom walls become cost competitive with standard systems as the wall area increases. This single system controls thermal expansion and contraction; seismic motion; building sway and movement; water diversion; and thermal efficiency. Subject to failures are extremely rare as it is designed in a very controlled environment. A curtain wall is defined as thin, usually aluminumframed wall, containing in-fills of glass, metal panels, or thin stone. The framing is attached to the building structure and does not carry the floor or roof loads of the building. The wind and gravity loads of the curtain wall are transferred to the building structure, typically at the floor line. Aluminum framed wall systems date back to the 1930â&#x20AC;&#x2122;s, and developed rapidly after World War II when the supply of aluminum became available for non-military use.

Vision Glass with Steel Construction

Vision Glass with Concrete Construction

On a steel construction, even with a cantilever,

On a concrete construction, the distance between

there still needs to be a girder at the end. So the

the curtain wall to the soffit can span a great

distance between the curtain wall to the soffit are

distance which gives a thin slab aesthetic from the

very close so the soffit can be viewed from the

exterior.

5.3 Stud-Backed Wall System

5.3 Stud-Backed Wall System (May also be CMU) This type of backup wall represents a large

Window Wall System

percentage of modern wall construction for several types of cladding. The reason is that steel studs are lightweight, fast to erect, economical,

Metal Stud Backed System

noncombustible, and are not susceptible to rot

(May also be CMU Wall)

or infestation. They do, however, have their

Exterior Sheathing

shortcomings. They corrode when exposed to continuous moisture, they deflect more than

Air/Moisture Barrier Membrane

masonry, and they act as thermal bridges

Rigid Insulation

conducting heat to or from the exterior.

2â&#x20AC;? Min. Air Space Exterior Finish (Shown on Right)

Note: It is important that no insulation is inside the stud cavity and have the insulation outside the stud cavity regardless of the climate condition.

5.3 Stud-Backed Wall System

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Masonry

What can go wrong

Efflorescence and cracking are the major problem

Studs systems are subject to more flexural move-

for masonry. Efflorescence is caused by moisture

ment than masonry or concrete wall systems. They

migrating through the mortar, dissolving salt with it,

are more prone to damage caused by water or

and leaching to the surface.

moisture penetrating behind the sheathing or interior finish. This incipient deterioration can continue

Wood Siding

for a relatively long time before detection. By that time, the structural stability of the stud system may

It requires periodic maintenance. Wood stain lasts

have reached a point where the whole system has

longer than paint. Using wood that has a natural

to be replaced at a cost that could reach as much

resistance to the effects of heat, wind, and rain is

as three times the original cost of construction. For

advisable to the applications. Redwood, cedar, and

this reason, it is imperative that the details be

cypress are recommended is the budget permits.

developed with full understanding of the various

Stucco It is hardy and durable finish if executed properly. It has a tendency to develop cracks if the supporting studs are not stiff enough, have wider spacing than usual, or lack frequent control joints.

defenses against water penetrations. Head, jamb, and sill details at window and door opening must be drawn at a large enough scale to show the termination and sealing of the edges of the adhered membrane, damp-proofing or waterproofing membranes, as well as air barriers. Although the work does not guarantee it will be executed correctly,

EIFS Delamination and moisture accumulation behind the insulation board is the bane of their system. Gypsum sheathing is not suitable. A masonry wall, cement board, or fiberglass faced GWB sheathing fastened to metal studs should be used instead.

Tile Veneer Tile is impervious to water, so it provides one of the better defenses against water penetration from the exterior. However, it is susceptible to attach by water vapor migrating from the interior of the building. This vapor can accumulate behind the tile, freeze and cause it to spall.

frequent site visits to spot check execution and provide guidance are also very important to prevent bad execution.

5.4 Precast Concrete Panel Wall System

window wall system 1” min. window placement from edge of panel

Precast concrete panels are shop-fabricated by experienced technicians under controlled conditions. The choice of finishes can be predetermined

precast concrete wall panel thickness

by sample selection. A full size mock-up can be constructed and tested for leakage or appear-

spray insulation

ance problems. Each panel is completed in one

light gauge metal

pour, thus avoiding the need for concealment of construction joints, and, in many cases, the panels are prestressed to minimize hairline cracks, resist bowing, and reduce deflection. In addition to these advantages, precast panels are durable and structurally adequate to resist lateral forces while spanning between floors to between columns. Panels may be used as a loadbearing wall element to combine both appearance and functions.

Guidelines for panel thickness for overall flat panel stiffness consistent with suggested normal panel bowing and warping tolerances. Note: It should not be used for panel thickness selection.

Panel dimensions

8’

10’

12’

16’

20’

24’

28’

32’

4’

3”

4”

5”

6”

7”

6’

3”

4”

5”

6”

7”

8’

4”

5”

6”

7”

8”

10’

5”

6”

7”

8”

5.4 Precast Concrete Panel Wall System

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What can go wrong Architectural precast concrete is produced under strict quality control by fabricators specializing in that type of construction. Examples of failure are extremely rare. A properly constructed precast panel with support points designed to accomodate Horizontal Spanning

Vertical Spanning

thermal movements, deflection, and supporting structure deformation due to lateral loads is one of the most dependable wall systems. There are, however, a few design decisions that can affect the optimal performance of the system. Avoid Deflection: - Support the panels directly on the column

Closed Shape

Open-ended Shape

Avoid Bowing: - Increase panel thickness - Stiffening ribs may be added to the back - Double layer of reinforcing steel may be used Avoid staining and streaking: - Use rough textured surface and darker colors - Cant the panels either upward or outward - include drips in the soffits to reduce streaking - Break up large blank surfaces with horizontal projections

Column and Spandrel

Multi-Story

Beam Cover

- Create vertical grooves below mullions and fins to channel the stain - Use rounded or splayed corners to reduce the concentration of rain at these locations

Panel Types This is a schematic representation of different ways in which panels may be configured.

5.5 Window Systems

5.5 Window Systems Window systems come in three major framing and glazing types: window wall, curtain wall and storefront. Each window systems create different facade expression, it can be combined to form any type of office building.

Window Wall System

Curtain Wall System

Storefront Systems

â&#x20AC;&#x153;Window wallâ&#x20AC;? is a term that can be used to

Typically used to glaze large areas of build-

Storefront systems are used for larger areas

describe various applications of glazing sys-

ings and is identified by the fact that it is

of glazing than standard windows; they typi-

tems that install between floor slabs and are

suspended outside of the building structure,

cally span from the floor to structure in the

set within a wall. This term can be used for

spanning past floor levels. Curtain wall gener-

ceiling above. Frequently, storefront systems

punched windows, ribbon windows, store-

ally is glazed from scaffolding erected on the

include entrance doors and vestibules, typi-

fronts, or other glazed openings that form a

outside of the building.

cally in the ground floor. Glass in storefront

wall of glass in a single story application.

systems is generally field installed, with contractors working from the floor of the building.

5.5 Window Systems

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Vision Glass Height Consideration As a general rule of thumb, for moderate to cold climate, using standard e-glazing window, the maximum vision glass height is 7’-0” to avoid

Window Wall System

Curtain Wall System

Storefront System

(stud-backed or precast concrete panel) 5’-0”

(stick-built or unitized)

(stud-backed or precast concrete panel)

5’-0”

energy loss. If the vision glass is greater than 7’-0”, a baseline heating needs to be provided in the interior to accommodate for the cold transfer

7’-0”

into the building. Shading device, reflective glass, or higher u-value glass (refer to chapter 7) are needed as part of the design decision to control the amount of heat transfer into the building.

5’-0”

Structural Glass Height Consideration Also as a general rule of thumb, for a standard size window wall system, the maximum window height span is 9’-0”. Higher window height, such as 10’-0” may need other means to support the

9’-0”

span such as thicker window mullion or using high-spanning steel reinforcement which can increase structural costs.

Mullion Spacing 5-ft module is chosen because it allows for a minimum room dimension of 10-ft as well as larger offices and conference rooms. Note: On the right, a schematic illustration of the different window system is shown to understand the achievable facade aesthetic but with the acknowledgement of the factor stated above to help you better evaluate your design decision.

10’-0”

5.6 Window Types

5.6 Window Appearance 60’-0”

Window Sizes Can Vary

Punched Window “Punched” window gets its application term by the

30’-0” 5’-0”

can vary greatly in cost due to their size and configuration. They require the most field work

13’-0”

a window. Like storefronts, punched windows

10’-0”

in the exterior wall of the building and filled with

5’-6” 7’-0”

concept that a cookie-cutter type hole is punched

Stud-Backed or Precast Concrete Panel Punched Window (Any Height)

because of individual window framing.

Ribbon Window “Ribbon” window gets its application term by simulating the look of a ribbon wrapped

modest and modules are kept repetitive. These types of systems can be designed to install in a

13’-0”

cost-effective, so long as opening heights are

10’-0”

floor slabs. Ribbon windows are typically most

5’-6” 7’-0”

horizontally. It can be any height between typical

Stud-Backed or precast Concrete panel Ribbon Window (Any Height)

variety of ways including shop-glazed (unitized) or field-glazed (stick-built).

Storefront Windows “Storefront” applications can sometimes be the

steel-reinforced glass wall. Storefronts can be very simple in nature or highly complex due to their various applications and design presence statement.

13’-0”

a typical 10 ft height. It requires a high-spanning

10’-0”

building. It normally span from floor to ceiling, at

2’-6” 10’-0”

heaviest and most costly glazed wall system on a

Stud-Backed or Precast Concrete Panel Storefront Window (Floor to Ceiling Height)

5.6 Window Types

arc G 6 9 1 ty polog y pattern b ook

Full Bay Expression

Split Bay Expression

Double Window Expression

60’-0”

30’-0” 5’-0”

VERTICAL EXPRESSION

HORIZONTAL EXPRESSION

PUNCHED OPENING EXPRESSION

30’-0” 5’-0”

Facade Expression: Schematic representation of possible design. Design Variable: Exterior Wall System, Window Types, Window Heightm Column Width, and Detail

30’-0” 5’-0”

5.7 Double-Skin Faรงade

5.7 Double-Skin Faรงades

Types of Construction

Generally speaking, double-skin facades are

Comparison of single-skin and

appropriate when buildings are subject to great ex-

double-skin facade onstruction.

ternal noise and wind loads. This can apply both to high-rise and low-rise structures. If buildings are to be naturally ventilated via the windows for as great a part of the year as possible, the double-skin construction offers distinct advantages in practice. Double-skin facades have a special aesthetic of their own, and this can be exploited architecturally to great advantage. The visual impression of transparency and depth, often in conjunction with a frameless form of construction in the outer skin, opens up new design paths.

Double-skin facades are based on a multilayer

Up to now, the external skins of this type of facade

principle. They consist of an external facade, an

have generally been constructed as a layer of sin-

intermediate space and an inner facade. The

gle glazing in toughened safety glass or laminated

outer facade layer provides protection against the

safety glass. An adjustable sunshading device

weather and improved acoustic insulation against

is usually installed in the intermediate space to

external noise. It also contains opening that allow

protect the internal rooms from high cooling loads

the ventilation of the intermediate space and the

caused by insolation. As a rule, the inner facade

internal rooms. The flow of air through the interme-

will consist of a supporting framework with a layer

diate space is activated by solar-induced thermal

of double glazing, which provides the necessary

buoyancy and by effects of the wind. To achieve

protection against thermal losses in winter. In

greater adaptability in reacting to environmental

almost all cases, the inner facade can be open to

conditions, it may be possible to close the open-

permit natural ventilation.

ings in the outer facade layer.

5.7 Double-Skin Faรงade

arc G 6 9 1 ty polog y pattern b ook

Box Windows The box window is probably the oldest form of a

Elevation of box-window facade. The division between each bay mean that

Solid wall

an opening light is also required for each bay,

two-layered facade. Box windows consist of a frame with inward-opening casements. The single glazed external skin contains openings that allow the ingress of fresh air and the egress of vitiated air, thus serving to ventilate both the intermediate space and the internal rooms. The cavity between the two facade layers is divided horizontally along the constructional axes, or on a room-for-room basis. Vertically, the divi-

Section through typical box-window

sions occur either between stories or between indi-

facade with separate ventilation for

vidual window elements. Continuous divisions help

each bay.

to avoid the transmission of sounds and smells

Inner and outer facade layer Solid wall

from bay to bay and from room to room. Box-type windows are commonly used in situations where there are high external noise levels and where special requirements are made in respect of the sound insulation between adjoining rooms. This is also the only form of construction that pro-

Plan of box-window facade. The divi-

vides these functions in facades with conventional

sions of the facade intermediate space

rectangular openings. Each box window element

are set on the construction area.

requires its own intake and extract openings, which have to be considered when designing the outer facade.

Room 1

Room 2

Room 3

5.7 Double-Skin Façade

Shaft-Box Facades

Elevation of a shaft-box facade. The arrows indicate the route of the airstream.

The shaft-box facade is a special form of box window construction. It is based on the “twin-face” concept developed by the Alco company in Munster and consists of a system of box windows with continuous vertical shafts that extend over a number of stories to create a stack effect. The facade layout consists of an alternation of box windows and vertical shafts segments. On every story, the vertical shafts are linked with the adjoining box windows by means of a bypass opening. The stack effect draws the air from the box windows into the

Section through a shaft-box facade.

vertical shafts and from there up to the top, where

Ventilation opening to shaft Inner facade layer

it is emitted. As a means of supporting the thermal uplift, air can also be sucked out mechanically via the vertical shafts.

The arrows indicate the route of the airstream flowing through the box windows into the common ventilation shaft.

Outer facade layer Horizontal division

Shaft-box facades require fewer openings in the external skin, since it is possible to exploit the stronger thermal uplift within the stack. This also has a positive effect in terms of insulation against external noise. Since, in practice, the height of the

Plan of a shaft-box facade. There are

stacks is necessarily low-rise and mid-rise build-

side openings in the shaft divisions in

ings. An aerodynamic adjustment will be neces-

the facade intermediate space.

sary if all the box windows connected to a particular shaft are to be ventilated to an equal

Room 1

Room 2

Room 3

degree. shaft

Shaft-box facades are suited where particularly high levels of sound insulation are required. because of the smaller size of the external openings.

shaft

5.7 Double-Skin Faรงade

arc G 6 9 1 ty polog y pattern b ook

Exhaust air opening

Services

Diagram of ventilation principle in the 8-story high shaft facade sections.

Ventilation stack Casement

7th floor Opening to shaft

6th floor

5th floor

4th floor

3rd floor Air-intake opening

Air-intake opening

View along intermediate space between facade layers in mock-up facade con-

2nd floor

struction. In every third bay, there is an extract shaft, which is open at the top. 1st floor

Room Depth

Bay width

5.7 Double-Skin Faรงade

Corridor Facades

Elevation of corridor facade. Air flows on the diagonal to prevent vitiated air

In corridor facades, the intermediate space

from the lower story being sucked in

between the two skins is closed at the level of each

with the air supply of the floor above

floor. Divisions are foreseen along the horizontal

(recontamination).

length of the corridor only where this is necessary for acoustic, fire protection or ventilation reasons. In the context of ventilation, this will usually be necessary at the corners of buildings where great differences in air pressure occur, and where openings in the inner facade layer would result in uncomfortable drafts from cross-currents. This problem can generally be avoided by closing off the corner

Section through a corridor facade.

spaces at the sides. In the rest of the corridor,

Separate circulation for each story.

there are likely to be only relatively small differences of air pressure, and these can be used to

Inner facade layer

support the natural ventilation.

Outer facade layer Horizontal division

The air-intake can extract openings in the external facade layer should be situated near the floor and the ceiling. They are usually laid out in staggered form from bay to bay to prevent vitiated air extracted on one floor entering the space on the

Plan of corridor facade. The intermedi-

floor immediately above. Where a corridor-facade

ate space is not divided at regular inter-

construction is used, the individual spatial seg-

vals along its horizontal length.

ments between the skins will almost always be adjoined by a number of rooms. Special care should, therefore, be taken to avoid sound transmission from room to room.

Room 1

Room 2

Room 3

5.7 Double-Skin Faรงade

arc G 6 9 1 ty polog y pattern b ook

Multistory Facades

Elevation of part of a multistory facade. The arrangement of the casement

In multistory faces, the intermediate space

opening lights depends on the ventila-

between the inner and outer layers is adjoined ver-

tion and cleaning concept chosen for

tically and horizontally by a number of rooms. In

the facade.

extreme cases, the space may extend around the entire building without any intermediate divisions. The ventilation (air-intake and extract) of the intermediate space occurs via large openings near the ground floor and the roof. During the heating period, the facade space can be closed at the top and bottom to exploit the conservatory effect and optimize solar-energy gains.

Section through a multistory facade. The external skin is set independently

Multistory facades are especially suitable where

in front of the inner facade. The inter-

external noise levels are very high, since this type

Inner facade layer

mediate space can be ventilated in all

of construction does not necessarily require open-

Outer facade layer

directions.

ings distributed over its height. As a rule, the rooms behind multistory facades have to be mechanically ventilated, and the facade can be used as a joint air duct for this purpose. As with corridor facades, attention should be paid to the problem of sound transmission within the intermediate space.

Plan of a multistory facade. The intermediate space is undivided and can be freely ventilated. Room 1

Room 2

Room 3

6. Lighting

OVERVIEW

Chapter Contents

Lighting is one of the most important factors affecting the interior spaces of an office and

6.1 Critical Dimensions

the psyches of those who work there. The quality of a space’s lighting will affect the way

Distance to Daylight Typical Layout & Variations

that space feels and is perceived by its occupants. An effective architect must realize the

6.2 Glazing

influential and evocative power of lighting and understand the numerous factors that affect

Properties of Glazing Common Types & Attributes Single, Double & Triple Pane

a space’s quality of light. In addition to providing a more pleasant working environment, an effective daylighting strategy can reduce an office’s electricity and heating costs, and thus

6.3 Quality of Daylight

should play a key role in any environmentally responsible design.

Window Size Effective Aperture Depth of Daylight Penetration Window Height

This chapter will discuss general strategies for using daylighting to achieving a favorable level

6.5 Shading Systems

of lighting in an office building. It will describe the many factors that affect daylight quality and methods for controlling it. It will also discuss ways to supplement daylighting with artificial light

Applications Integrated Shading Depth of Shading Light Shelves Seasonal Strategies

to achieve ideal lighting levels for various spaces within an office.

6.4 Atria Geometry & Ratios Roof Type Reflectivity of Materials Drawbacks

6.6 Lighting & Office Layout Ideal Lighting Levels Direct & Indirect Lighting Effect on Furniture Arrangement

6.1 Critical Dimensions

Distance to Daylight The floorplate of a typical office building has been refined throughout history based on several key factors affecting office use and construction. One of the most important such factors is the access of the office’s occupants to natural light. Most office buildings maintain a critical dimension of 45’ between the inside of the building’s exterior walls and the central core (Fig. 1). This is typically considered to be the farthest distance that any

45’

occupant can be from a window while still enjoying the benefits of the natural light and views that the window provides. Any spaces beyond this 45’ dimension are typically reserved for functions such as mechanical rooms, rest rooms, and vertical circulation. These are areas that people do not inhabit continuously for extended period of time and where access to daylight are not a priority. 45’ It is important to note that, while these dimensions are a good rule of thumb to use in American office buildings, daylighting requirements are much more stringent in other countries. In Europe, for example, every worker is required to have access to natural light. This requirement effectively limits typical European floorplates to 25’ deep or less.

Fig. 1

6.1 Critical Dimensions

arc G 6 9 1 ty polog y pattern b ook

45’

Fig. 2

85’

45’

Fig. 3

Fig. 4

Typical High Rise Floorplan

Atrium High Rise Floorplan

Articulated High Rise Floorplan

Daylit Wall Length: 600’

Daylit Wall Length: 720’

Daylit Wall Length: 760’

Maximum Floorplate Depth: 45’

Maximum Floorplate Depth: 85’

Maximum Distance To Daylight: 45’

Maximum Distance To Daylight: 22’-6”

Maximum Distance To Daylight: 45’

In a high rise floorplan of typical dimensions, the

An atrium scheme can effectively cut an occu-

Increasing the building perimeter allows for a

building perimeter will equal approximately 10 to

pant’s maximum distance to daylight in half, allow-

deeper floor plate and a greater overall floor area

15 times the depth of the floorplate. Increasing

ing for better working conditions and a more even

while keeping the daylighting level and maximum

the perimeter will provide more area for daylight to

quality of natural light throughout the building. See

distance to daylight constant.

enter and thus increase the building’s daylighting

chapter 6.5 for more information.

performance.

100

6.2 Galzing

6.2 Glazing

The type of glazing used in a building’s windows

Daylight Transmission vs. Heat Gain

will have a profound effect on the quality of light in its interior. There are several important factors to consider when selecting a glazing system:

Solar Heat Gain Coefficient (SHGC) 0.9

Measures the amount of solar energy that is transmitted through the glass. Windows with a low SHGC will transmit less heat to the interior, leading

0.8

to greater occupant comfort and reduced cooling costs. See Chapter 3.x for more information.

Heat Gain Coefficient

Solar Heat Gain Coefficient

0.7

Visible Transmittance (VT) Measures the percentage of visible light that is

0.6

able to pass through a window. An increase in VT generally means an increase in SHGC as well

0.5

(Fig. 5).

Luminous Efficacy Constant ( Ke)

0.4

Measures a window’s ability to simultaneously transmit daylight and prevent heat gain. It is

0.3

expressed as the ratio of (VT) to (SHGC). The higher the Ke Value, the greater the daylighting

0.2

performance of a glazing system. Ke =

0.1

VT 1.5 (SHGC)

U-Value & R-Value 0

Daylight Transmission (%)

Daylight Tranmission (%)

Fig. 5 - Daylight Transmission vs. Solar Heat Gain

100

U-Value & R-Value are inverse measurements. While U-Value measures a material’s ability to conduct heat, R-Value measures its ability to resist heat flow. Windows with a low U-Value (and thus a high R-Value) will provide greater insulation and moisture control, especially in cooler climates.

6.2 Glazing

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101

Single, Double & Triple Pane Glass Double-pane glass is the standard for most office applications but triple-pane may be used where energy efficiency is a high priority. Single-Pane glass is almost never used in offices due to its poor thermal performance and relatively low strength. There are many kinds of low-e coatings and films that may be applied to the glass to further increase its performance. In colder climates, where the main goal is to retain heat, these coatings are usually applied to the outer surface of the innermost pane. In warmer climates, where the goal is to prevent solar gain, these coatings are applied to the inner surface of the outermost pane. Another option for increasing thermal performance is to fill the gaps between panes with an inert gas, typically Argon. These gasses have a higher RValue than air, and thus provide better insulation.

Glazing Type

Fig. 6 - Single, Double, and Triple-Pane Glass

Thickness (inches)

Solar Heat Gain Coefficient (SHGC)

Light Transmittance (VT) (%)

U-Value

R-Value

Luminous Efficacy Constant (K e)

Standard Single-Pane Glass

0.25

0.81

0.89

1.09

0.92

0.73

Single-Pane Glass w/ Heat-Rejecting Laminate

0.25

0.46

0.73

1.06

0.94

1.06

Double-Pane Insulated Glass

0.70

0.79

0.48

2.08

0.75

Tripple-Pane Insulated Glass

0.67

0.74

0.36

2.78

0.74

Low-e Double-Pane Glass

0.71

0.75

0.33

3.03

0.70

High Efficiency Low-e Glass

0.25

0.37

0.7

0.29

3.45

1.26

Suspended Coated Firm Glass

0.25

0.35

0.55

0.25

4.00

1.05

0.34

0.53

0.10

10.00

1.04

Double Suspended Coated Film Glass Fig. 7 - Properties of Common Glazing Types

102

6.3 Quality of Daylighting

Window Size In general, the larger the windows a space has, the more daylight that space will receive. A facade’s Window Wall Ratio (WWR) is the most effective way to measure window size as it relates

WWR

Glazing Type VT EA Single Pane

Glazing Area: 200 sf ÷ Fig. 8 - Punched Windows

Total Area: 810 sf

.25

.89 .22

to daylighting potential. WWR is defined as a facade’s net glazing area to its total area.

Double Pane .79 .20

Effective Aperture

Triple Pane

As discussed in Chapter 6.2, the Visible

.74 .18

Transmittance (VT) of a window’s glazing has a great impact on the amount of light allowed to enter a space. For this reason, WWR alone is not an effective measure of daylighting performance. A more accurate measurement is the glazing

WWR

Glazing Type VT EA Single Pane

Glazing Area: 240 sf ÷ Fig. 9 - Ribbon Windows

Total Area: 810 sf

.30

Window Wall Ratio by the Visible Transmittance of

Double Pane .79 .24

its glazing. A higher Effective Aperture will mean

Triple Pane

more daylighting potential, however, it will also

.74 .22

mean more solar gain and glare. See Chapter 5.x

WWR

Glazing Type VT EA Single Pane

Total Area: 810 sf

.67

Triple Pane

WWR =

Glazing Area Total Facade Area

.89 .60

Double Pane .79 .53

Aperture is determined by multiplying a facade’s

.89 .27

for more information on facade composition.

Glazing Area: 540 sf Fig. 10 - Curtain Wall

system’s Effective Aperture (EA). Effective

.74 .50

EA = WWA x VT d =

h x 2.5

6.3 Quality of Daylighting

arc G 6 9 1 ty polog y pattern b ook

Depth of Daylight Penetration The distance that daylight will penetrate into a space depends on several factors. The geometry of the space - its width and the angle of its walls

4’

6’-6”’

- will effect how far light is able penetrate. The reflectivity of a space’s materials is another

16’-3”

important factor; spaces containing many highly

45’

Fig. 11

reflective surfaces will allow light to penetrate much deeper that an identical space with matte finishes. However, the most important and easily quantified factor effecting the depth of

4’

daylight penetration is the positioning of a space’s

9’

windows. 22’-6”

Window Height

45’

The dimension from the finished floor to the top of

Fig. 12

the window (h) is the single most important factor in determining the distance that daylight from that window will penetrate into the building (d). A good rule of thumb to use when trying to determine the depth of daylight penetration is that d = 2.5h. (Fig.

9’

11-14). Windows placed higher on the wall will allow light entering the building to reflect off of the

22’-6”

ceiling and thus penetrate further into the room.

45’

Raising the ceiling height in a room is one way

Fig. 13

to take advantage of this principle (Fig. 14). See Chapter 1.x for more information. The size of a window will affect the intensity of the light emitted into a room, but will not alter the depth

9’-6”

of light penetration (Fig. 12 - 13). 23’-9” 45’

Fig. 14

103

104

6.4 Shading Systems

Applications While effective natural lighting is important for the success of an office building and for the health and well-being of its occupants, it is also important for that daylight be carefully controlled and regulated. Direct daylight leads to solar heat gain which can increase the demands on a buildingâ&#x20AC;&#x2122;s mechanical systems (See Chapter 3.x for more information). It also results in sharp contrast between areas of light and shadow and an uneven lighting of the buildingâ&#x20AC;&#x2122;s interior spaces. One of the best ways to prevent these problems is through the implementation of an exterior shading system. Shading will provide a much more diffuse and even

Fig. 15 - Exterior Shading

quality of light (Fig 15). The ideal strategy for shading a building will vary greatly depending on the climate that it is located in, its latitude, and its elevation. For this reason, 3D modeling, solar path analysis, and shading studies are indispensable tools in the design of an effective shading system. Horizontal louvers are the most effective way to deal with direct light. In the Northern Hemisphere, where the strongest afternoon sun is in the southern sky, these louvers are usually installed on the southern and sometimes the northern facade of a building. For a finer level of daylighting control, vertical louvers, or fins, may be installed

Fig. 16 - Integrated Shading

on the east and west facades of a building to regulate indirect light.

6.4 Shading Systems

arc G 6 9 1 ty polog y pattern b ook

Integrated Shading As an alternative or a supplement to exterior shading, a wide variety of glazing options are available to control direct light. Glazing that incorporates reflective films or metallic particles can be very effective at preventing solar gain. Translucent glass can also be used to block direct sunlight where exterior views are not a priority (Fig. 16).

÷4

Depth of Shading When assessing the effectiveness of a particular shading system, it is important to remember that the depth of individual shading elements is not as significant as the combined depth of all elements in the system. For example, ten feet of total shading will provide the same amount of protection from solar gain and glare whether its is arranged as one ten-foot deep louver, five two-foot deep louvers, or twenty six-inch deep louvers, as long as those

÷6

elements are evenly spaced on the building’s

÷6

facade (Fig. 17-18).

Fig. 18 - Equivalent Options for Distribution of Shading Elements

Fig. 17 - Depth of Horizontal Louvers

105

106

6.4 Shading Systems

Light Shelves One specific type of exterior shading that is particularly effective is the light shelf. A light shelf is a horizontal louver that is located at near the top of a wall of fenestration. In most applications, light shelves are used both on the exterior and on the interior of the building. The light shelf blocks direct light from entering the window, thus reducing solar gain and glare. At the same time, it reflects light up onto the spaceâ&#x20AC;&#x2122;s ceiling, lighting it and producing a more even quality of light that penetrates deeper into the room (Fig. 18). One particular advantage to light shelves is that, Fig. 18 - Light Shelf

even if the shades are drawn on the lower portion of the window, light will still enter the space through the upper portion. This allows occupants to close the shade to further decrease glare and solar gain while still receiving the benefits of natural light (Fig. 19).

Fig. 19 - Light Shelf with Shades Closed

6.4 Shading Systems

arc G 6 9 1 ty polog y pattern b ook

Seasonal Shading While preventing solar gain is an important requirement of shading during the spring and summer months, solar gain can often be beneficial during the colder months of the year. Allowing solar gain in winter can reduce the amount of mechanical heating required to achieve a comfortable working environment, thus reducing a buildingâ&#x20AC;&#x2122;s total energy costs. For this reason, some of the most effective shading systems are those that take advantage of the difference in solar angle between winter and summer. In addition to the solar heat gain benefits, these strategies will allow sunlight to penetrate deeper into the building during the dimmer winter months. One way to take advantage of this principle is to size and position a buildingâ&#x20AC;&#x2122;s louvers so that they block direct sunlight in the summer, when sunâ&#x20AC;&#x2122;s azimuth is greater, and allow sunlight to enter in the winter, when the angle is lower (Fig. 18). Another effective strategy is to use strategically placed trees as a form of natural shading. In the summer, the trees will block sunlight and provide the building with shade. In the winter, when their branches are bare, they will allow sunlight to pass through and enter the building. (Fig. 19)

Fig. 18 - Seasonal Shading, Summer

Fig. 19 - Natural Shading, Summer

(above) and Winter

107

108

6.5 Atria

In buildings with deeper floorplates or where a high quality of natural light is a design priority, an atrium is an excellent way of increasing the amount of daylight that enters a building. The implementation of an atrium effectively cuts an occupants maximum distance to daylight in half and allows h

Attached

for a higher and more even level of daylighting

throughout the space.

The best way to quantify the daylighting performance of an atrium is by measuring

Fig. 21 - Atrium Measurements

its Daylight Factor (DF). The Daylight Factor describes the ratio of outside illuminance over inside illuminance, usually expressed as a

Linear

PAR =

w l

percentage. The higher the DF, the more natural light is available in the atrium. The Daylight Factor is affected by the geometry of the atrium, as well as its roof form and the reflectivity of its materials.

SAR =

h w

Plan Aspect Ratio (PAR) The most efficient shape for the plan of an atrium is a circle. In atria with non-circular plans, the PAR can be used to measure the effectiveness

Enclosed

WI =

h x (l + w) 2xlxw

of the space’s geometry. The PAR is equal to the atrium’s width divided by its length. An atrium with a PAR closer to 1 (square) will have better dayighting performance than one with a PAR closer to 0 (linear).

Semi-Enclosed Fig. 20 - Atrium Types

Section Aspect Ratio (SAR) The SAR measures the ratio of an atrium’s height to its width. A low SAR indicates a shallow atrium and a relatively high Daylight Factor.

6.5 Atria

arc G 6 9 1 ty polog y pattern b ook

Well Index (WI) The WI combines the PAR and SAR into one vertical surface area of the atrium’s walls to the horizontal surface area of its plan. An atrium with a low WI will be shallower and have a greater Daylight Factor than one with a higher WI. As

Daylight Factor

comprehensive measurement that compares the

Fig. 24 - Flat Roof

WI increases, Daylighting Factor decreases exponentially (Fig. 22)

Roof Form There roof of an atrium can take many shapes depending on the atrium’s geometry, structure,

Well Index

Fig. 22 - Well Index vs. Daylight Factor

and design intent. An atrium with an open roof will allow for the maximum Daylight Factor, however, this is not always practical. Three common roof forms are shown in Figures 24-26 and Figure 23 shows the effect that each of these forms have on

In a shallow atrium, a flat roof will provide the greatest DF, however it also allows for the most Solar Heat Gain. A sawtooth roof will decrease solar gain and is also more effective at providing light to lower floors. In any atrium, the performance of the roof structure will depend

Contribution to Daylight Factor (%)

an atrium’s Daylight Factor.

Flat Monitor Sawtooth

with respect to the sun. For example, light entering at a low angle which make them very

Fig. 25 - Light Monitor

largely on the building’s location and orientation monitors are very effective at admitting light

Flat Monitor Sawtooth

Depth of Atrium (Number of Floors)

Fig. 23 - Effect of Roof Form on DF

useful at high latitudes or in winter months.

1 Because of this, 2 lighting studies 3 should be 4

conducted before finalizing any atrium design.

Fig. 26 - Sawtooth

109

110

6.5 Atria

Reflectivity The reflectivity of an atrium’s materials will also affect its Daylight Factor. Surfaces with a higher reflectivity will allow light to penetrate farther into an atrium and increase daylighting performance. Because an atrium’s effectiveness is dependant on so many varied factors, it is possible to compensate for shortcomings in one area by increasing performance in another. For example, if building or site geometry prohibits the atrium from having a low Well Index, a desirable Daylight Factor could still be achieved by using more reflective materials on its interior surfaces.

Drawbacks To Atrium Buildings In spite of the daylighting benefits that atria Fig. 27 - Daylighting in Typical Building and Atrium Building

provide, there are several drawbacks which should be carefully considered before an atrium scheme is implemented. First of all, the empty space taken up by the atrium on each floor will reduce the building’s Net to Gross Ratio and its Floor Area Ratio with respect to its site. See Chapter 0.X for more information. In addition, any atrium that is three or more stories tall must conform to strict smoke and fire control regulations. See International Building Code (IBC) Section 909 for specific requirements.

6.6 Lighting & Office Layout

arc G 6 9 1 ty polog y pattern b ook

6.6 Lighting & Office Layout An effective daylighting strategy supplemented

Fig. 28

by intelligent use of artificial lighting is one of the

Private Office:

most crucial factors contributing to the success

50 - 70 Foot-Candles

of an office space. The standard unit of measure for light in a space is the foot-candle (FC), which measures the amount of light that falls on a given surface. Foot-candles can be measured with a photometer or any camera with a built-in light meter. The optimal level of illumination varies greatly depending upon the type of space in question and the specific tasks being performed there. A private

Fig. 29 Conference Room: 30 - 50 Foot-Candles

office usually requires between 50 and 70 footcandles of illumination (Fig. 28). This can usually be achieved with a combination of natural light and one or two artificial light sources. A conference room must be much more adaptable due to the wide variety of uses they have, including meetings and presentations (Fig. 29). Thus it will usually have several independently controllable

Fig. 30

light fixtures and either blinds or shades for

Open Workspace:

daylight control.

60-80 Foot-Candles

Open workspaces require a higher level of illumination (Fig. 30). A high level of daylighting is very important in these spaces. Artificial lighting is usually provided by indirect fixture mounted on the ceiling, however individual fixtures can be provided at each workstation to provide more flexibility and reduce energy costs.

111

112

6.6 Lighting & Office Layout

Direct Lighting vs. Indirect Lighting

Fig. 31

Fig. 32

Direct Lighting, or “downlighting”, is the most

Indirect Lighting, or “uplighting”, uses a diffused

energy efficient method of lighting a space.

light to illuminate a space. This is achieved by

Light from the fixture is allowed to directly enter

bouncing light off of a reflective surface and

the space, allowing for the maximum amount of

usually off of the space’s ceiling. Lighting the

illumination. However, this method of lighting

ceiling provides a softer, more even light and

provides a higher level of contrast which can lead

greatly reduces glare. The relative pros and

to uneven lighting and glare.

cons of direct and indirect lighting are outlined in

Fig. 33 - Energy Consumption in a Typical Office

Figure 34.

Pros

Direct Lighting

Indirect Lighting

Cons

Suggested Applications

Most Energy Efficient Wide Range of Manufacturers Lower Initial & Maintenance Cost Can be Integrated into HVAC System

Less Architectural Hard to Avoid Glare on Computer Monitors Requires more Wiring and Mounting

Reception Areas Private Offices Utility Spaces

Best for Glare Control More Innovative & Architectural

Less Energy Efficient Higher Initial Cost

Open Workspaces Circulation Spaces Conference Rooms

Fig. 34 - Direct Lighting vs. Indirect Lighting

6.6 Lighting & Office Layout

arc G 6 9 1 ty polog y pattern b ook

Furniture Arrangement

Direct View to Outside

The location and orientation of office furniture with respect to sources of daylight will have a Glare

great impact on the comfort and productivity of a building’s occupants. Studies have shown that access to natural light and exterior views have a beneficial effect on the health and psyche of workers. A scheme such as the one shown in Figure 35 will provide occupants with the greatest amount of natural light and direct views to the exterior; however, it also exposes the them to direct glare which leads to eye strain and visual discomfort. Another option is to orient workstations as shown in Figure 36. This configuration reduces

Fig. 35

the occupants’ visual contact with the outside; Oblique View to Outside

however, it also greatly reduces the amount of direct glare that they have to deal with. In spite of this they are still subject to indirect glare reflecting off of their computer monitors and workstation walls. In both schemes, the window’s shades must be closed in order to avoid glare, thus negating any natural light or views to the outside. See Chapter 7.x for more information on Layouts.

Glare In a schemes such as these, the implementation of an exterior shading system, such as those discussed in Chapter 6.4, are ideal because they will reduce glare while still giving occupants the benefits of natural light and views.

Fig. 36

113

7. Floorplan

Overview

Chapter Contents

The geometry and constraints of the human body are the generator of the office environment

7.1 Human Scale + Constraint

at its finest grain, and all other component parts of the workspace must respond to that

Standing Seated Plan

geometry. These elements are arranged in space to facilitate one of a variety of modes of work, and to facilitate or segregate the interactions of the individual workers according to this collaborative philosophy.

7.2 Planning Modules + Components 5’ Module 240°/120° Degree Module Modular Components/Workstations

7.3 Spaceplanning Patterns This chapter is a study, first, of the spatial generator of the human form. The chapter will then outline the planning modules and physical components of the workplace in relation to that form. Finally, the chapter will study the patterns in which these physical and human components can be combined within a space to suit a given mode of work. The intent of this chapter is to give the designer the means with which to generate office landscapes tailored to the particular needs of the individual and the broader corporate entity, either by assembly of pre-manufactured modular components, or through design of custom elements.

The Farm Linear Cubicles The Organism 240° 120° The Epicenter Hard Walled Offices + Hierarchical Plans

116

7.1 Human Scale & Constraints

7.1 Human Scale + Constraints

7.1 Human Scale & Constraints

arc G 6 9 1 ty polog y pattern b ook

Fig. 1 Standing Figure

Fig. 2

Fig. 3

Vitruvian Man, ca.1487

Le Modulor, 1948

Leonardo da Vinci

Le Corbusier

117

118

7.1 Human Scale & Constraints

7.1 Human Scale + Constraints

arc G 6 9 1 ty polog y pattern b ook

Fig. 4 Seated Figure

7.1 Human Scale & Constraints

119

120

7.1 Human Scale & Constraints

7.1 Human Scale + Constraints

arc G 6 9 1 ty polog y pattern b ook

Fig. 5 Figure In Plan

7.1 Human Scale & Constraints

121

122

7.2 Planning Modules / Compoents

7.2 Planning Modules/Components

Fig. 6 Linear Worksurface + 5â&#x20AC;&#x2122; Grid

Fig. 7 Cubicle + 5â&#x20AC;&#x2122; Grid

7.2 Planning Modules / Compoents

arc G 6 9 1 ty polog y pattern b ook

Fig. 8 240째 Workstation + Hexagonal Grid

Fig. 9 120째 Workstation + Hexagonal Grid

Fig. 10 Casework + Hardwall + Grid

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124

7.3 Space Planning Patterns

7.3 Space Planning Patterns The Farm

LINEAR Program Precedents- Financial, Creative -Maximum Density -Maximum Acoustic Transmission -High Potential Shared Worspace/Team Overlap -High Project Team Mobility -High Visibility -Minimum Personal Identity -Minimum Net Workspace Within Primary Reach -Minimum Enclosure

Metrics

Fig. 11

Workspaces-

SF Per Worker-

32 sf

LF worksurface-

420 lf

LF Per Worker-

5 ft

Floor Area-

2,700 sf

Total Area of Worksurfaces-

1,050 sf

Worksurface Area Per Worker-

12.5 sf

Floor Area : Worksurface Area-

2.57:1

7.3 Space Planning Patterns

arc G 6 9 1 ty polog y pattern b ook

Low

High

Sound Intesity

Low

High

Visual Overlap

Plan Detail

Fig. 12

125

126

7.3 Space Planning Patterns

7.3 Space Planning Patterns The Farm

Cube Program Precedents- Call Center, Corporate -High Density -High Net Workspace Within Primary Reach -Moderate-High Enclosure -Moderate Personal Identity -Low-Moderate Acoustic Transmission -Low Potential Shared Worspace/Team Overlap -Low Project Team Mobility -Low-Moderate Visibility

Metrics

Fig. 13

Workspaces-

SF Per Worker-

90 sf

LF worksurface-

300 lf

LF Per Worker-

10 ft

Floor Area-

2,700 sf

Total Area of Worksurfaces-

705 sf

Worksurface Area Per Worker-

23.5 sf

Floor Area: Worksurface Area-

3.83:1

7.3 Space Planning Patterns

arc G 6 9 1 ty polog y pattern b ook

Low

High

Sound Intesity

Low

High

Visual Overlap

Plan Detail Fig. 14

127

128

7.3 Space Planning Patterns

7.3 Space Planning Patterns The Organism

240째 Program- Creative, Corporate -High Density -High Net Workspace Within Primary Reach -High Acoustic Transmission -High Potential Shared Worspace/Team Overlap -Moderate-High Visibility -Moderate Personal Identity -Moderate Project Team Mobility -Low-Moderate Enclosure

Metrics

Fig. 15

Workspaces-

SF Per Worker-

85 sf

LF worksurface-

320 lf

LF Per Worker-

10 ft

Floor Area-

2,728 sf

Total Area of Worksurfaces-

768 sf

Worksurface Area Per Worker-

24 sf

Floor Area : Worksurface Area-

3.55:1

7.3 Space Planning Patterns

arc G 6 9 1 ty polog y pattern b ook

Low

High

Sound Intesity

Low

High

Visual Overlap

Plan Detail Fig. 16

129

130

7.3 Space Planning Patterns

7.3 Space Planning Patterns The Organism

120째 Program Precedents- Creative, Corporate, Real Estate, Education -High Density -High Project Team Mobility -High Acoustic Transmission -High Potential Shared Worspace/Team Overlap -Moderate-High Visibility -Low Enclosure -Low Net Workspace Within Primary Reach -Low Personal Identity

Metrics

Fig. 17

Workspaces-

SF Per Worker-

62 sf

LF worksurface-

264 lf

LF Per Worker-

6 ft

Floor Area-

2,728 sf

Total Area of Worksurfaces-

528 sf

Worksurface Area Per Worker-

12 sf

Floor Area : Worksurface Area-

5.17:1

7.3 Space Planning Patterns

arc G 6 9 1 ty polog y pattern b ook

High

Sound Intesity

Low

High

Visual Overlap

Plan Detail Fig. 18

131

132

7.3 Space Planning Patterns

7.3 Space Planning Patterns The Epicenter Hardwall/Casework Program- Creative, Corporate, Legal, Financial -Maximum Enclosure -High Personal Identity -High Net Workspace Within Primary Reach -Moderate Potential Shared Worspace/Team Overlap -Low-Moderate Visibility -Low Density -Low Project Team Mobility -Low Acoustic Transmission

Metrics

Fig. 19

Workspaces-

Executive

General

SF Per Worker-

Executive

225 sf

General

100 sf

LF worksurface-

Executive

60 lf

General

180 lf

LF Per Worker-

Executive

15 lf

General

10 lf

Floor Area-

2,700 sf

Total Area of Worksurfaces-

603 sf

Worksurface Area Per Worker-Exec.

45 sf

23.5 sf

Gen.

Floor Area : Worksurface Area-

4.48:1

7.3 Space Planning Patterns

arc G 6 9 1 ty polog y pattern b ook

High

Sound Intesity

Plan Detail

Low

Visual Overlap

Fig. 20

133

8. Sociology

Overview

Chapter Contents

Office Buildings are usually constructed for one of two purposes. One is a more speculative

9.1 Hierarchical Plan

approach, in which developers foresee a market need for a new office building. The second is a privatized approach, in which large companies want to create a flagship office building or have the resources and need for an office building of their own. In the latter there is room for innovation as well as a driving force which wishes to create a high-quality structure.

The layouts of office buildings; however, are driven by the users. This can result in one of three typical floor plans. One is the hierarchical layout, in which private offices and conference rooms are located on the perimeter of a floor and the general employees and their cubicles are located at the center. The second one is an inverted-hierarchical layout. In this plan the workers and their workspace are located at the perimeter of the plan and the private offices and rooms are at the center. The third layout is the non-hierarchical layout. This is an open plan, in which workers have more interaction and are able to be more productive.

This chapter will explore all three of these types of layouts and how they are used in office buildings. Multi-tenant plans will also be explored, in which a mix of these three plan layouts can be applied to one floor.

Professional Uses Basic Floor Layout Typical Bay Section Office Infrastructure / Interaction

9.2 Inverted-Hierarchical Plan Professional Uses Basic Floor Layout Typical Bay Section Office Infrastructure / Interaction

9.3 Non-Hierarchical Plan Professional Uses Floor Layouts Bay Section Office Infrastructure / Interaction

9.4 Multi-Tenants Floor Configurations Office Infrastructures / Interactions Floor Requirements

136

8.1 Hierarchical Plan

Private Outer Ring Common Inner Ring

In this type of plan there is a private outer ring and a communal inner ring. Located in the outer ring

Core

are private offices and conference rooms. The inner ring contains the lower ranked workers as well as spaces for them to collaborate, eat, and

45’

Typical Bay

interact.

45’ Typical Upper Level Plan

This type of hierarchy was the typical office layout, but more companies are moving towards an inverted- hierarchical plan. In the hierarchical plan, the common worker aspires and strives to have his or her own office. They can move up the ladder of

Private Outer Ring Common Inner Ring Core

success, and it will be solidified and commended by having their own personal space.

45’

Typical Bay

Typical Mid-Level Plan

In this flow of hierarchy the highest ranked workers

45’

are on the outer ring and those at the lower ranks are centralized and surround the core. This location of rank allows for those in charge to open their doors and delegate to those below them. Such is the scenario in law firms, corporate offices, and other companies with a ladder of success.

Private Outer Ring Common Inner Ring Core 45’

Typical Bay

Typical Suburban Plan

45’

8.1 Hierarchical Plan

arc G 6 9 1 ty polog y pattern b ook

Core

Common Inner Ring

Private Outer Ring

Typical Bay In this perspective view, you can see the typical bay of a hierarchical plan, and it becomes evident of the aspiration that a lower ranked employee could have. The conference rooms and private offices on the perimeter of the building provide both the clients and those in charge a sense of importance. Sunlight and views are very important as they make employees more productive. For this reason companies are now using glass walls to separate the private offices and conference rooms. The glass allows more light to come into the office, thus making everyone a more productive employee. The glass also allows easier for those in charge to interact with those below them. Making a better work environment.

Typical Hierarchical Bay

137

138

8.2 Inverted-Hierarchical Plan

Common Outer Ring Private Inner Ring

The inverted-hierarchical plan is self explanatory. The private offices and conference spaces that

Core

crowded and blocked the outside world are moved towards the core and the lower ranked employees are given the perimeter. As a result of increase

45’

Typical Bay

productivity from natural light and fresh air, this

45’

model is more appealing to companies that are

Typical Upper Level Plan

driven by average employee. It still provides the hierarchy required to evoke aspirations and competitiveness amongst the employees who want to climb the ladder of success, while making the work environment friendlier and more productive.

Common Outer Ring Private Inner Ring Core

These types of layouts are found in progressive

45’

Typical Bay

law firms and corporate offices as well as in design fields such as architecture firms, engineering firms,

Typical Mid-Level Plan

advertising, and other such fields.

45’

Inverted-hierarchical plans also allow workers to interact and collaborate easier than the hierarchical plans. They force interaction within the open plan in the outer ring and the private offices in the inner ring.

Common Outer Ring Private Inner Ring Core 45’

Typical Bay

Typical Suburban Plan

45’

8.2 Inverted-Hierarchical Plan

arc G 6 9 1 ty polog y pattern b ook

Core

Private Inner Ring

Common Outer Ring

Typical Bay In this perspective view, you can see how those in charge can oversee more efficiently the employees around them. It is also easier to see how the average workers would become more productive when they have a better light and ventilated working environment. This plan focuses those in charge to look

Typical Inverted

and interact with those working for them, thus mak-

Hierarchical Bay

ing office interaction and communication easier. The workers are happy, those in charge still have their private office, and hierarchy still exists.

139

140

8.3 Non-Hierarchical Plan

Scattered Private Spaces Common Open Plan

As the office layout evolves the plans become more worker oriented and open, with minimal privatization. In the non-hierarchical plan the

Core

private ring is consumed by the open plan ring, and the necessary private offices and conference

45’

Bay

rooms are then brought back and scattered around

45’

the plan. Factors driving this type of office layout

Upper Level Plan

are the increase in employee productivity, environmental agendas, and economical planing. Common Open Plan In this open plan the employee interaction is facilitated through open plan. Collaboration is easier encountered and productivity increases. This is why this layout is currently very popular in creative

Scattered Private Spaces Core 45’

Bay

professional environments. These fields include architecture, engineering, planing, advertising, and

Mid-Level Plan

other such fields.

This type of plan also allows developers to create more office buildings without being hindered by speculation of use and marketability. The layout can be manipulated and laid out to accommodate the users more easily because of the nature of the

Common Open Plan Scattered Private Spaces Core

plan. 45’

Bay

Suburban Plan

45’

8.3 Non-Hierarchical Plan

arc G 6 9 1 ty polog y pattern b ook

Core

Scattered Private Spaces

Shared Open Plan

Scattered Private Spaces

Bay In this perspective view it is evident how an open plan can facilitate office interaction while at the same time keeping its necessary private spaces. The conference room is on the outside of the plan, while the office stays closer to the core, keeping blurred the line of hierarchy. If hierarchy does need to be established, this can be done more openly and subtly through the assigned office furniture. It puts those in command in direct contact with the lower ranked employees.

Non-Hierarchical Bay

141

142

8.4 Multi-Tenants

1 Open Plan

When dealing with one tenant per floor, it is easier to locate a receptionist space. However, when dealing with multi-tenants more careful planning is required to keep the separate offices independent

Core Open Plan Reception Spaces

while allowing them to share common program, such as rest rooms and means of egress.

Two Tenant Open Plans If two or more tenants occupy a space, it becomes necessary to create a dedicated reception space

Private Spaces

for each tenant. This creates the need for a corridor connecting the different offices. In these

Common Open Spaces

layouts you can find two of the same types of

Core

layouts divided in one floor or two or more different office configurations in one floor. These office floors are usually taken up by smaller firms who

Corridor Reception Spaces

donâ&#x20AC;&#x2122;t need an entire floor to themselves. This can

Four Tenant Mixed-Plans

create a bigger profit for developers, depending on how they are charging the rented space. They can charge the various offices for use on the common space, making profit on what would normally be charged once by charging it two, three or even four times.

Open Spaces Reception Spaces Common Egress

Private Spaces

Two Tenant Mixed-Plans

8.4 Multi-Tenants

arc G 6 9 1 ty polog y pattern b ook

Multi-Tenants Perspective In this perspective we see just one of many configurations in which a multi-tenant floor plan can be laid out. It shows the approach that needs to be considered when arriving to the offices. As well as the very different atmospheres created within each office as a result of the layout.

Private Spaces Reception Spaces Core Open Plan

Tenant 4

Tenant 3 Multi-Tenant Perspective

143

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OFFICE BUILDING ARCH G691 GRADUATE DEGREE PROJECT STUDIO FALL 2008 This publication has been prepared as part of a five week graduate thesis studio assignment in the Northeastern University School of Architecture for the Fall 2008 Architecture G691 course. Other publications in this series include urban retail, hotel, and parking garage typologies, all produced by graduate students in the Northeastern University architecture program.