P32076 Urban Design Issues I “How do we safeguard and deliver high levels of environmental quality of land in the context of increasing intensification of land use?� October 2012
Group 2
Charlotte Fleming Andrew Hoare Mawgan Pengelly
1.0 Preface This document is submitted by Group 2 in response to the Urban Design Issues I Module (P32076).
The Module Issue, or question, will initially be broken down to fully analyse its importance and broadness. The group will explore what is meant by “environmental quality” and “intensification”, which will be addressed in the Introduction section of this document (page 7).
The group will answer the Module question through a detailed, graphically interesting report which will highlight the principles of what makes spaces work for lively and diverse cities at two given densities.
The following students produced this work:
Following on from this, and with a clear definition of both terms, we can develop the Issue through a design toolbox, decribing how we are assessing the terms (page 33).
This work will be completed by the three group members, their differing professional backgrounds and ages will be highlighted for the case study analysis - offering a broader analysis of what makes a good place for a range of people. Specific tasks carried out by each group member were as follows:
Charlotte Fleming, 24, Town Planner Andrew Hoare, 39, Architect Mawgan Pengelly, 34 Landscape Architect / Illustrator “The purpose of this Module is to mark the transition from initial studio-based skills to individual enquiry, where skills learnt from Year 1 are applied and adapted to new and varied contexts. As opposed to site-based work, the Issues I Module provides a significant alternative, being Issue based, and makes no assumptions concerning the principles to be adopted. In essence, this Module addresses current or future problems and opportunities in the design and management of urban form and living” (Urban Design Issues I and II course handbook, September 2012).
These will be based in part on analysis of city districts throughout the world through a series of case studies (page 37). We will apply the results of the case studies (in terms of environmental quality and intensification) to a series of generic models (page 59).
Charlotte Fleming: Case study scoring, analysis and 5 facility plans, Portsmouth facility plan, text and planning policy summary, facilities research. Andrew Hoare:
In turn we will then apply these models to a chosen site in the UK, which will lead on to sketch proposals, conclusions, and the Issues II Module (page 65).
The nominated issue for this Module is:
“How do we safeguard and deliver high levels of environmental quality in the context of increasing intensification of land use?”.
Document text, case study scoring, case study analysis, case study models, hybrid models, Portsmouth proposals, site models and sketch designs, “thought trees”, FAR ratios analysis, 200/500 schedules, powerpoint presentation, Jan Gehl criteria sketches, research.
Mawgan Pengelly: Document text, document graphic design, document illustrations, document title page, case study scoring, case study colour wheels and data charts, powerpoint presentation, neighbourhood model and analysis, Portsmouth site analysis, research.
01
1.0 PREFACE
Finally, the principles gathered from the case studies and models will be applied to a test site, at the two density levels, before being assessed to see if the group achieved its goal. We will finish with a conclusion, offering potential ways to deliver high levels of environmental quality, whilst increasing intensification of land use. Topics will be suggested to take forward into Issues II at the end of this document.
ANALYSIS
Following the case study analysis, the group will create a series of generic models, at given densities of 200pph and 500pph, which operate at a variety of scales, highlighting the required needs of each.
ISSUE
[DEFINE]
PRINCIPLES
[GEHL]
CASE STUDY
[5 NO.]
PROTOTYPE
[MODEL]
APPLICATION
The group’s methodology for Issues I is a simple 3 point investigation, of Introduction, Analysis and Application. We will begin by giving clear definitions of the Issues I question, before selecting an assessment tool for analysing a series of case studies in terms of their levels of environmental quality and intensification.
INTRODUCTION
Methodology
Figure 1.1 - Methodology
SITE
[RESOLVE]
03
2.0 Contents
01
1.0 Preface Module I overview and methodology
29
33 05
5.0 The Human Element 6.0 Assessment Toolbox
59
8.0 Design Models
60
Design model expanded
62
F.A.R. hybrid model principles
2.0 Contents
07
3.0 Introduction
37
7.0 Case Studies
65
9.0 Site Application
10
What do we mean by “high levels of environmental quality”?
38
Amsterdam “Berlage” introduction
66
Ravelin Park introduction
What do we mean by “intensification of land use”?
40
Dresden “Wurfelhaus” introduction
68
Ravelin Park facilities
42
Genoa “Town Palace” introduction
69
Ravelin Park analysis
16
23
4.0 Urban Sprawl vs Compact City
44
New York City “Upper East side” introduction
72
24
Urban Sprawl
46
Sana’a “Towerhouse” introduction
74
Ravelin Park 200pph master plan
25
The Compact City
48
Case study comparison plans
76
Ravelin Park 500pph master plan
50
Case study facilities plans
52
Case study F.A.R. / efficiency values
79
10.0 Conclusions
54
Case study 12 Gehl quality criteria assessment
57
Case study conclusions
87
11.0 References
Note: All figures, illustrations, tables and photographs, unless otherwise stated, are by the authors of this document.
Planning policy, facilities and F.A.R. schedules
05
3.0 Introduction
“No good for cities or for their design, planning, economics or people, can come of the emotional assumption that dense city populations are, per se, undesirable. The task is to promote the city life of city people, housed in concentrations both dense enough and diverse enough to offer them a decent chance at developing city life” Jane Jacobs, “The Death and Life of Great American Cities”
The purpose of this chapter is to answer the Module Issue question in a clear and defined way, and to give a brief overview of the methodology for this project
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1947 “land use planning in the UK has remained fundamentally unchanged since 1947*�
3.0 INTRODUCTION
2007
TODAY
“first time more people on earth are living in urban rather than rural areas**”
“how do we safeguard and deliver high levels of environmental quality in the context of increasing intensification of land use?”
* & ** “Revistiting London’s First Garden Cities” Jeff Risom & Maria Sisternas, Gehl Architects
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“How do we safeguard and deliver high levels of environmental quality in the context of increasing intensification of land use?�. Module Issue
Beijing, China (source: http://gehlcitiesforpeople.dk/)
3.0 INTRODUCTION
What do we mean by “high levels of environmental quality”?
What makes a good place?
In order to assess what is a “high level of...” we must first define what is “environmental quality”? It is an open ended question that could be answered in a number of ways by a variety of professions. An Environmental Scientist may refer to issues such as air quality/pollution, the diversity of flora and fauna, or noise levels in a given area. As Urban Designers, we can answer the question in terms of the quality of the urban space, its quality of space. How this can be assessed is a more complex issue. Many emotional responses are due to the individual, their own perceptions, own tastes, own fears etc. What is possible is to firstly look at some of the key principles of what makes good urban spaces, the fundamentals of Urban Design (Figure 3.1).
Fundamentals of urban design
permeable space social interaction
designing for people not cars
open space provision
?
a mix of uses good public transport
In assessing what is a “high level of environmental quality”, it is worth revisiting the fundamentals of urban design*: • Character - a place with its own identity • Continuity and Enclosure - a place where public and private spaces are clear • Public Realm Quality - a place with attractive and successful outdoor areas • Ease of Movement - a place that is easy to get to and move through
clear public / private distinction
sense of well-being / safety
what is the key?
fundamentals of urban design
legible space sensory richness
walkable access to local facilities a distinct sense of place
• Legibility - a place that has a clear image and is easy to understand • Adaptability - a place that can change easily • Diversity - a place with variety and choice *(source: Better Places to Live By Design, CABE, 2001)
Figure 3.1 - What makes a good place?
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Environmental quality
How to assess the quality of a place?
There are clearly many influences on the quality of spaces, however there is a fundamental link between the quality of the space itself and the quality of the buildings, or architecture around it. These two factors need to work together to create the place.
Part of the methodology of this report is to use an assessment tool that will investigate several case studies - in terms of their environmental quality. There are many noted authors who have produced tables and diagrams that can be used to assess the built form. We are presenting two examples, and will select one of them to use for the case study assessment section
Through good design, the place must be adaptable, safe and must respond to the needs of space at differing scale, from the plot, to the neighbourhood, to larger town and city scales. In order to create truly successful places, the designer needs to address social interaction, walking distances and the provision of uses and local facilities, all under the umbrella concept that both the public realm and architecture need to be high quality and built to last.
Figure 3.3 is an illustration from the seminal design piece “Responsive Environments - A Manual for Designers”. It shows a 7 levels that affect the experience of the individual in a given place. These 7 levels, permeability, variety, legibility, robustness, visual appropriateness, richness and personalisation, are key factors in assessing the quality of the built form. In “Cities for People”, Jan Gehl illustrates the 12 qualities for the pedestrian landscape (Figure 3.4). These 12 topics are split in 3 main categories, protection, comfort and delight. Gehl puts them in this order as before any response can be made to an environment, one first has to feel safe in a place. Overarching all the 12 criteria is that the place should have good design and architecture, and that these are not to be treated as isolated values. The strength of this 12 point assessment is that all 12 are required at a good level to create a good place. By leaving one or more out of the thought process when designing will only create a semi-successful place.
Environmental quality “thought tree” Figure 3.2 shows the Thought Tree for environmental quality. This process chart is about the difference between what people need to make a good place, and what they feel. There are fundamental urban design principles, but these are combined with a variety of personal feelings and perceptions that all combine to create a sense of well-being to the individual.
Yet both of these assessment tools cannot be used in isolation. The benefits of first hand experience, recorded stories, plans/sections and photos are obvious. It is also worth examining the proximity of local facilities / open space and the mix of uses along with other factors.
Figure 3.2 - Environmental Quality thought tree
Figure 3.5 - Gehl 12 quality criteria illustrated
“How do we safeguard and deliver high levels of environmental quality in the context of increasing intensification of land use?�. Module Issue
Sienna, Italy (source: http://gehlcitiesforpeople.dk/)
3.0 INTRODUCTION
What do we mean by the “intensification of land use�? Global and regional population growth (demand) yet limited areas of land and quantities of energy (supply) combined with an increasing desire/necessity to live/work in or around the edge of cities has created the two-tier issue of urban sprawl and unsustainable land use and lifestyles in cities. As the city boundary increases in size due to population and economic growth, often with low residential densities, transport infrastructure becomes strained and inefficient, energy/utility supplies become outdated, the mix of land uses reduce or are placed separately, and the concentration of places of work with places to live weakens and splits.
the city - it will grow in size, but how and where?
if the city build outwards, it is easy to cause Urban Spread / suburbia / a car dependent city, which is inefficient, a poor use of capacity, and an unpleasant sensory experience as a pedestrian
These factors combine to reduce the quality of living in the city - in order for a city to be viable and sustainable, there needs to be a mix of enough people per area, with a variety of building types, uses and good spaces. Figure 3.7 illustrates how a city can grown in different ways, some of which will reduce the vitality of a place.
What is density? The key term to answer the Module question is density. Simply put, density refers to how many residencies or people occupy an area of land. Usually this is assessed as dwellings per hectare (dph) or people per hectare (pph). These figures can be used to both assess existing settlements (against their environmental qualities) as well as proposed new settlements (that are sustainable). In reality not only are higher densities desirable, they will soon be essential for all cities. The intensification of land use should provide a vision of efficient land use solutions that provide a variety of uses and diversities, offering social, economic and energy sustainability with an efficient public transport system, while retaining a sense of place, a hierarchy of spaces and high quality city spaces that are walkable.
if the city build upwards, in the form of towers and skyscrapers it can create very efficient use of land, and high densities - but at the cost of poor quality space around the building, the space that lives in the shadow, as well as a disconnect from the ground, from those who live at the top
the aim should be to provide the right criteria for a city to regenerate from within, with high quality mixed uses and housing that responds to the social, economic and environmental needs of the place, up to, but not exceeding capacity. This helps create a diverse, vital and walkable city.
17 Figure 3.7 - How the city can grow
Intensification
Intensification and number of people
Urban areas are most intense at their centres - usually caused by contextual setting, higher land values and amount of available land to build upon. Taller buildings tend to be placed at centres, to make efficient use of the higher land cost.
Figure 3.9 illustrates the relationship between density of people and the vitality they bring to a place. Each of the 3 examples are shown with a population of 7,500 people, but as the densities vary, so does the efficiency of walking distances, ability to sustain shops and community facilities, as well as provide a viable public transport system.
Around these main centres can be found smaller centres, perhaps served by a reduced number of facilities, or shops. It is here that we can see the variety of scales in intensification, often shown in grid layouts or concentric rings. This grading of intensification, or density, can be used to calculate optimum public transport usage, the placement of schools, health and community centres and shops. Intensification should not strive for a unobtainable perfect efficiency, as often this results in standardization. In fact the point at which standardization becomes apparent in a city is the point at which the environmental quality will begin to slide down. The quality of the public realm and architecture (which as a concept should never result in standardization) has to remain high for the city to be a people place.
Intensification of land use “thought tree” Figure 3.8 shows the Thought Tree for this question. The key starting point is the “How much and what” line, which refers to the quantity of density required. Unlike Environmental Quality, this can be represented as a definitive number, but it is the view of the group that densities when applied to urban design / cities, should not be represented in a series of spreadsheets and numbers - what works in one place may well not work in another. Lifestyle links to Environmental Quality, the making of good city spaces that are livable, with enough diversity of choice to make them exciting places to be. Vision refers to the process of applying which density and land use, or combination or land uses are best suited to a given area or zone. Figure 3.8 - Intensification thought tree (right)
7,500 people Gross density 50 people per hectare • Large land-take • Dispersed facilities - no district centre • 60% are over 500m from the centre so tend to drive for local trips
Difficult to justify bus
7,500 people Gross density 100 people per hectare • Reduced land-take • Clear central facilities • 30% are over 500m from the centre so may tend to drive for local trips • Public transport (bus) should be viable
Bus service begins to be viable
7,500 people Gross density 150 people per hectare • Use of local facilities increases • Only 13% are over 500m from the centre • Able to provide viable and regular public transport services
Figure 3.9- The relationship between density and land-take (source: “Housing for a Compact City” Urban Task Force, 2004)
Bus service fully viable. May justify other forms of public transport
3.0 INTRODUCTION
Quality and style of design Intensification can be applied using a variety of architectural styles or elements. The aim should be to make them high quality as standard. Figure 3.10 shows how three layout styles can all achieve the same density - but they will result in very different qualities of public and private spaces. Intensification (or high densities) tend to lead to a knee-jerk reaction, based in part to the confusion of the term with over populated, disease ridden settlements (like the Dickensian slums that inspired the Garden City Movement), and the memory of the tower block estates of the 1960s / Le Corbusier’s City of Tomorrow (1929). These settlements failed because they were poorly designed and constructed, had limited other land uses around them, and were sometimes filled with those individuals who were deemed too socially diversive to be placed anywhere else.
Terraced housing • 50 dwellings per hectare • Clear private gardens but limited other open space • On street parking
Low-rise flats • 50 dwellings per hectare • No private gardens, but large areas of open space - yet public/private confusion exists • Communal parking areas
High-rise flats • 50 dwellings per hectare • No private gardens, but large areas of open space - yet public/private confusion exists • Shading issues • Communal parking areas • Those living at the top may feel disconnected from ground level uses Figure 3.10- Varying density forms
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Applying ideals and land uses to a city It is the view of the group that previous year’s Issues I assignments missed the importance of human scale and place-making in their application of land uses. We refer to this as the “blanket” approach, wherein the designer treats the page as blank, and overlays a grid or grid like structure (for ease of calculating square metres per person). This inevitably ends with a model that is not adaptable to the real world (unless you are designing a new mega city in the middle east) and is shocking in its starkness and lack of human quality. A model that is not adaptable is pointless, so the group has decided to embark upon a “tailored” approach, based on urban design principles, use of “human” spaces and an awareness that standardization through maximum efficiency is not the answer to the module issue. The use of a standardized layout style (a grid for example) may work well in the proper context, but it can only work at block and neighbourhood level effectively. Even a city like New York occasionally breaks the grid, and creates a varied sense of place through the variety of buildings that line the streets.
Regular grid
Elongated grid
Irregular grid
VS Figure 3.12 - “Blanket” vs “Tailored”
“Blanket” approach?
“Tailored” approach?
• grid or similar large scale zoning
• key concepts, fundamentals of urban design applied creating distinct, diverse, mixed use communities
• based upon statistics, literal land use areas per person - blocks of open space etc
• ADAPTABLE - “human space” responsive to context economically, socially and environmentally
• meaningless - NOT EASILY ADAPTABLE to real world Irregular
Spider web
Leaf
Dart board
Figure 3.11 - Examples of urban layout patterns
Jigsaw
Hexagonal
• examine ratios of built / open space • standardization of buildings and spaces does not create placemaking, good quality city space
• open space network includes “the street”
• tries to tick all the boxes, but is not a “human space”
• cities able to regenerate from within, long term sustainability
• no clear hierarchy of space / scale - a “sim city”
• aware that the density / mix will change over time
3.0 INTRODUCTION
“Tailored” approach key principles
structure intensity of development around access to public transport and local facilities, with a hierarchy of spaces
increase land efficiency on new / existing plots, through good design, whilst improving public realm for walking / cycling, examine area ratios
new housing and other land uses must be high quality, adaptable, and respond to local need and diversity - fundamentals of urban design applied
planning policy must update, locally and regionally, to be able to correctly define and plan the city NOW, not from 1947
Summary In order to accommodate rising populations and city growth, without resulting in “Urban Sprawl” (see section 4.0), higher density settlements are a necessity. They are the only sustainable way to resolve a very complex situation, but each case needs to be addressed on its own merits. As soon as a “standard model” is introduced, the city is at risk as it will not be diverse enough. Densities, land uses, as well as building type, should be varied where possible, and always to a high quality, with a clear hierarchy, offering a large variety of choices for the volume of people within the city and the uses offered to them. It would be simple to create a very densely populated area (such as a slum), but the Environmental Quality of the space must be to the same high standard as the building themselves should be. The qualities of space are various, some of these are very personal and can not be easily measured, but there are some general principles that can be applied to what makes a good space - the fundamentals of urban design. A good public transport system is only possible with a correct density level, and in turn this can reduce car usage and allow more innovative designs of open space (including the street itself), helping to create the walkable city. Yet the Compact City can also lead to additional congestion it is argued - therefore there must be other transportation methods easily available that make car use less necessary, whether through pricing, ease of use, flexibility or convenience. Following on from a brief investigation into Urban Sprawl vs Compact City, and the Human Element of this Module, the group will begin an analysis of several case studies, resulting in a series of generic models that meet environmental quality and density criteria, and could be applied to a test site for further analysis.
open space treated as overall concept, not just green squares on a plan must have a connected network including “the street” itself 21
4.0 SPRAWL vs COMPACT
Summary Dense city populations (such as The Compact City) can be a major benefit to a city. Yet this is not a mathematical magical number that can be applied to every city throughout the world. There is clearly a sliding measure, based upon points at which lively city life, diversity, and economic prosperity can flourish and be strong enough to regenerate within the city radius. “Proper city dwelling densities are a matter of performance they cannot be based on abstractions about the quantities of land that should ideally be allotted for so-and-so many people. We ought to look at densities in much the same way we look at calories and vitamins. Right amounts are right amounts because of how they perform, and what is right differs in specific instances”. Figure 4.7 - (Above) Kowloon walled city 3D model (source: Trimble 3D Warehouse) Figure 4.8 - (Below) section through Kowloon (source: http://www.deconcrete.org)
Jane Jacobs, “The Death and Life of Great American Cities”
Urban Sprawl is fundamentally unsustainable, in terms of the growing population, energy and cost requirements, limited supply of land, and because it fails to address the developing size of most cities. The Compact City also has many flaws, the greatest of which is its capacity to destroy itself by becoming too dense. Potential benefits over public transport use and the use of cars causing congestion have yet to be definitively proved, as many studies suggest higher congestion in The Compact City. Perhaps the ideal solution is to have The Compact City settlement model, surrounded by buffer zones of green (to contain and regenerate the city through the years) in addition to having limits on developments on the edge of the city or buffer zone. Internally, the Compact City must have a good public transportation system, with mixed land uses across it (rather than single land use blocks), have city spaces that people enjoy to be in, and have restrictions and reviews on maximum density levels.
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5.0 The Human Element
“If we are to encourage pedestrian and cycle traffic and realize the dream of lively, safe, sustainable and healthy cities, we must begin with a thorough knowledge of the human scale” Jan Gehl, “Cities for People”
The purpose of this section is to highlight the importance of the human element in city design, in terms of quality of spaces / environment, diversity of people and places, and the mix of facilities that a city needs to be vital
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People and space
Facilities for people 3
Failing to recognise the importance of people, and especially huProviding local facilities for people, easily accessible by either walkman scale in a development can result in unpleasant, over powering, cycling or public transport are essential foundations for a sucImportantly, the traditional neighbourhood is nearly always laidshould out on the ing and frightening places to be in. As soon as the city is designed cessful design model of what a city be. Facilities should be primarily for the car, or spaces become too large, we immediately placed in groups in nodal points, or centres, which offer good links basis of convenient, pedestrian accessibility with the edge rarely being lose a connection with the place. for people.
1
more than a 5 minute walk away. Usually, neighbourhoods link up along established transport corridors to form a chain of development that 22 “The human body, senses and mobility are the key to good the ur- centre The traditional UKneighbourhood. neighbourhood is structured so that as a pedesincreases in density towards of each Preserving ban planning for people. All the answers are right here, encaptrian, the edge is rarely more than 400m / 5 minute walk away. Muland reinforcing this hierarchy of density is fundamental to achieving a sulated in our own bodies. The challenge is to build splendid tiple neighbourhoods are linked along transport spines which forms urbanabove form. cities at eye height withsustainable tall buildings rising the beautiful a “string of pearls” of development, each of which has a higher lower stories”.
3
density centre (Figures 5.2 and 5.3).
Jan Gehl, “Cities for People”
All the elements that make up a liveable city are3best understood as a pedestrian, either walking or cycling through a space. The relationship between people and space is based upon our ability to see details at certain distances, be comfortable or uncomfortable with certain numbers of people around us etc. Therefore the human 1 scale, the walkable city, the details that can only be seen at ground level as we move, are what form the identity of place - the sense of place.
Close contact
Distance
Multiple levels
2
Low speed
2
One level
3 Lack of orientation
ENHANCING SOCIAL CONTACT
3
Speed
2
1. Urban centre 2. Neighbourhoods 3. Transport corridors
0m
40
1. Urban centre 2. Neighbourhoods
Image 7
Figure 5.3 - Neighbourhood centres (source “The Urban Place Supplement”, Essex Design Guide, 2007)1. Urban centre
2. Neighbourhoods 3. Transport corridors
The size of population will also inform the type and number of facilities required, from primary / secondary schools, health centres, shops, leisure centres, public transport etc. As a group we propose that these uses be distributed where possible in mixed-use centres, rather than as single land use plots. This is to encourage diversity and vitality in the city life.
Sense of orientation
Figure 5.1 - Spatial conditionsImage and social7contact (source “Life Between Buildings”, Jan Gehl, 1987)
2
3
Overlap
Separation
PROHIBITING SOCIAL CONTACT
2
basis of convenient, pedestrian accessibili more than a 5 minute walk away. Usually, established transport corridors to form a c increases in density towards the centre of and reinforcing this hierarchy of density is sustainable urban form.
Image 8 Figure 5.2 - Neighbourhood walking distances (source “The Urban Place Supplement”, Essex Design Guide, 2007) Neighbourhood (400m radius/5 minute walking distance)
Im
N w
5.0 THE HUMAN ELEMENT
Social activity and public space
Facilities for people
It is ironic that at a time when more people live closer to one another than ever before in the UK, that our levels of social interactions with neighbours, strangers etc, have probably never been lower. Table 5.1 shows how the scale of the place can affect our social activities.
A given number of people will require certain land uses in order to support them in their life, from shops to health centres. Figure 5.4 and Table 5.2 outline some basic figures for calculating what facilities are required, and at what level. The three concepts in the provision of local facilities/services are:
The UK suffers from “Little England” mentality, and as a nation we are very defensive of our personal space. This combined with the more isolated social lifestyle that many people now live does not create an ideal combination, we are socially inward looking.
density of population - people per hectare (pph)
SOCIAL ACTIVITIES
‘Intimate’
• Limited number of people • Common interests or background
Elaborate social contacts
Residential streets, Streets near schools, Public space near working places etc
People know each other (only by face) • Many people
Mainly passive
City streets, City centres etc
• Many different backgrounds
Seeing and hearing each other
‘Anonymous’
• No direct physical contact
None
Primary school
4000+
Secondary school
8000-16000
Health centre (four doctors)
10000-12000 5000-7000
Post office
5000-10000
accessibility standards - how far a given amount of people can walk
Community centre
4000-15000
urban structure - the directness of routes that lead to facilities
Library
12000-30000
District centre (superstore)
25000-40000
Leisure centre
25000-40000
Table 5.2 - Population catchments for key services (source “The Plot”, Tarbatt, 2012)
Summary The design of a place should be based upon the way people use the space. That is a fundamental principle. Pedestrians must come first, at a time when the car is often given priority and rule over the street. This only creates areas that people do not want to be. It is important to remember that high density does not necessarily create lively places. It can often have the opposite effect. Liveliness can be a combination of many factors, including the compactness of the city, the walking distances, the priority of the car over other forms of transport, and good quality architecture and public realm. Once again we can see a sliding scale, where a certain number of people are required to make a space diverse and vital enough to sustain itself, but that this number has to relate to the quality of the spaces available, and a whole host of technical, contextual, social, economic and environmental factors.
Motorways, infrastructure Table 5.1 - Relation between social activity and public space (source “Urban Theory and Design of Public Space”, presentation by Gehl Architects, 2004)
2000-4000
Pub
Greetings, conversations, discussions, games
‘Public’
Nursery school
1500-5000
Perhaps through the design of the spaces we inhabit, we can reignite this feeling amongst us? CHARACTERISTIC
Indicative catchment population
Local shop
Good urban design can play a role in bringing people together, even if it is as a collective, rather than friends - but this is a defining feature of the human condition, we, as a species, have always grouped together, whether to hunt, create places or to give us a sense of identity and belonging.
KIND OF SPACE
Service
Figure 5.4 - Accessibility standards for key services (source “The Plot”, Tarbatt, 2012)
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6.0 Assessment Toolbox
“Good analysis of the site and its context are necessary if the principles of sustainable development are to be converted into practice in the development scheme. It is critical that the designers engage with this appraisal and understand its significance” Barton et al, “Shaping Neighbourhoods”
The purpose of this section is to detail the assessment methods and criteria that will be applied to the case studies in section 7.0
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3 = Agree, these qualities are present
(green)
FE
CU CE RE
V C E L I O L RIM SE E N E / CR CE FE VICU IM EL OL R SE ENE E /
TRAFFIC / ACCIDENTS FEEL SAFE
TRAFFIC / ACCIDENTS FEEL SAFE
T
I G
D E L
ES
1 = Disagree, these qualities are not present (red)
Based upon the scoring system, a colour will be applied to each of the qualities, which will then be represented in a colour wheel, shown blank in Figure 6.2. Each member of the group has a different background, different age, and different profession. Therefore as well as individual marks we can work out average scores for the group. Clearly this is subjective, and a larger survey would yield a more conclusive study, but with time short, this is our method.
ES
OP
PO
S ITE EE
IT UN RT PO ALK P O W TO
OP TO POR S T ST TUN AY AN D / ITES
(blue)
UN
2 = Some of these qualities are present
IT UN RT PO LK OP WA TO
I
OPPORTUNITES FOR PLAY OP AND PO EXERCISE
SCALE
S S RT TO PO ITE E OP UN SE RT TO PO OP
(intensification)
ER
OPPORTUNITES FOR PLAY AND EXERCISE
OPPORTUNITES TO SIT
3. Examining the F.A.R. percentage/efficiency of the case studies
P EX
OPPORTUNITES TO SIT
(walkable local facilities)
T AN Y R AS T LE ANN S O ES P SE R Y C UN AS IEN E O PL XPNESR CES UN SEE EN
SCALE
2. An assessment of local facilities within a 400m/1km radius
P
OP TO POR S T ST TUN AY AN D / ITES
(environmental quality)
H
T H I G
D E L
1. Jan Gehl’s 12 quality criteria (from “Cities for People”)
OP
TO OR OP AS ENJ TUN PE OY ITI TO POR E CT S C POS S AS ENJ TUN LIM ITIV PE OY ITI E A CT TE E S C POS S LIM ITIV E AT E
N
The 12 point Jan Gehl quality criteria (Figure 6.1) will be applied to the case studies by each member of the group, and assigned a score of 1, 2 or 3. The score reflects whether the group member believes these qualities are present:
P R OP T RO ET CE C T T I I OO N
The toolbox for assessing the case studies chosen by the group will consist of the following four tools:
VE TI Y ES SI O R NC PO N S RIE S E PE EX
1. Environmental quality - Jan Gehl VE TI Y ES SI O R NC PO N S RIE S E PE EX
The Toolbox
R F O C OM
R F O C OM
3 2
RT TA UNIT LK ES LIS AND TE N
RT TA UNIT LK ES LIS AND TE N
1
T
T
Figure 6.2 - Blank colour wheel, for case study assessment of environmental quality
2. Walkable local facilities 4. Case study research text
Using Google Maps or similar, the group will draw 400m and 1km radii from the case study itself. These reflect a 5 minute walking distance and just over 10 minute walking distance respectively, and these values are fundamentals in providing a good range of local facilities, without the need to get into a car and travel great distances.
(social / economical / environmental context)
We will list the facilities under the following headings:
Figure 6.1 - The 12 quality criteria concerning the pedestrian landscape (Source: “Cities for People”, Gehl, 2010)
Primary / secondary school Recreation Health Worship Retail Open space Office / industry
o
6.0 ASSESSMENT TOOLBOX
3. Intensification efficiency We will examine the potential for intensification through two efficiency calculations. The first of these is F.A.R. which stands for Floor Area Ratio (Figure 6.3). At a time when developable land is scare and expensive, especially in cities, the designer must be aware of providing spaces that are more efficient in their use of land. If space can be saved, or more used efficiently for residential, commercial or other uses, then additional land can be given for open space. F.A.R. works out the relationship between site or plot area, and the total floor area within that plot. For example a tower placed on a tight site would have a high F.A.R. score, due to the number of stories in the block, whereas a single bungalow on a very open site would have a very low score (F.A.R. is usually expressed as a percentage, above 100% would infer an efficient use of the land, below 100% would infer an inefficient use of the land).
2
m (FLOOR AREA)
The second efficiency rating we will use will be Habitation Efficiency (Figure 6.4), which calculates the population in a block or plot against the percentage coverage of built form.
gross population plot coverage %
Summary This 4-point toolbox for assessing each of the case studies will provide a broad response to the chosen examples. Yet the group is aware that isolating each of these tools on their own is not what makes a good place for people. The efficiency ratings we will be assessing with could easily give positive results to an overcrowded slum, such as Kowloon City, as investigated earlier in section 4.0. Therefore the results must be viewed as a whole, balanced against one another, but remembering that the key concept we have identified is making good quality places for people.
= Habitation Efficiency Figure 6.4 - Calculating Habitation Efficiency
4. Research text The group will also provide a written background article to each of the case studies, examining contextual, social, economic and environmental issues, as well as the history of the place. This will help shape an overview as to how and why the place came to be, and what helped shape its growth or form.
2
m (SITE RATIO) = FAR Figure 6.3 - Calculating F.A.R. efficiency
les in the project the density is
35
7.0 Case Studies
“it is important to recognise the diverse needs of a locality different ages and life stages, income levels, varied ethnic, household and family groupings, different cultures, lifestyles and levels of mobility. The spatial design of the neighbourhood can either support or restrict and frustrate it” Barton et al, “Shaping Neighbourhoods”
The purpose of this section is to assess, using the method described in section 6.0, five international case studies of varying density levels - the five studies will be introduced with background information before being assessed
37
5 case studies - compared Amsterdam, “Berlage” Perimeter block
Dresden, “Wurfelhaus” Urban villa • High land values force intensification
• Intensification with broad loose grain
• City constraints led to intensification
• Perimeter block with streets
• Low density block
• High density block
• Street width 20m
• Street width 16m
• Building height 17.5m
• Building height 23m
• Street width 19.5m • Building height 17.5m
Case study plan / sections 1:5000
Genoa, “Town Palace” Courtyard
Case study plan / sections 1:5000
Case study plan / sections 1:5000
7.0 CASE STUDIES
Summary New York City, “Upper East Side” Tower
Case study plan / sections 1:5000
Sana’a, “Towerhouse” Townhouse
• Land scarce and huge population
• Urban Sprawl corrected by intensification
• Grid layout
• Organic street pattern
• Street width 30m
• Street width 4m
• Building height 60m
• Building height 18m
Case study plan / sections 1:5000
The group decided to study what social, economic and cultural drivers underpinned the development of the case study cities and how this influenced and generated a vernacular typology. Our selection of 5 case studies cannot be regarding as fully comprehensive and it can only be regarded as an abstraction or ‘snapshot’ of residential typologies from the wider urban form and neighbourhood to the specific urban block. However our case study cities each have a particular method of dealing with intensification. Density has become a major topic in urban design and architecture in recent times. The case study examples have also been selected for their approach to safeguarding quality. For example Sana’a is quite unique in being an ancient city that had to deal with intensification approximately 2000 years before industrialized cities. Sana’a could be applied to modern urban design in so far as the typology suits fine grain yet dense development and is structured on the relationship between street and public open spaces. Our study of New York focused on the early 20th century buildings rather than the mega towers now common in developed economies throughout the world. The Upper East Side of New York is characterized by mid rise towers which offer a fine balance between intensification and quality. The quality of the street scene can only be described as urban and yet however due to the street and building proportions the quality of the place is not overly affected by intensification. If we were to offer criticism of New York it would be the shattered scale between people and built environment. The approach taken to address intensification in Dresden and Genoa offers a subtle yet significant development of a similar urban form and typology. Due to very different cultural and economic drivers the cities approach to intensification led to a development of the urban villa and courtyard villa both used in generous perimeter block situations. However if we apply our quality assessment tool against these typologies we can measure and demonstrate a shift in environmental quality. A tipping point is reached when an abstract qualitative assessment records a poor environmental quality associated with higher densities. The most common typology studied here can be seen in Amsterdam Zuid and the Berlage perimeter blocks. The typology is characterized by the most recognizable urban form, the street, lined each side by four storey housing with steep pitched roofs. However the city needed intensification and the basic elements of street, house and block have been fine tuned to deliver very high levels of floor space which for the most is also of a very high quality.
Site photos / plans (source: The Urban Housing Handbook, Firley & Shahl, 2009)
49
Local facilities Amsterdam, “Berlage” Perimeter block
Dresden, “Wurfelhaus” Urban villa
400m radius
Primary school Secondary school Recreation Health Worship Retail Open space Offices / light industry
aerial imagery shown not to scale (source: Google maps)
1km radius
Genoa, “Town Palace” Courtyard
1km radius
1km radius
400m radius
400m radius
7.0 CASE STUDIES
Summary New York City, “Upper East Side” Tower
Sana’a, “Towerhouse” Townhouse
Testing the non-residential facilities of the five study sites against the suggested criteria, indicates non-residential Testing the non-residential faciltieis of how the five little study sites against the suggestedarea there criteria, indicates how little non-residential area there are in existing cities which are in existing cities which appear to be still developing. appear to be still developing. Genoa
1km radius
400m radius
1km radius
400m radius
Genoa per ha
Sana
Sana per ha
New York
New York per ha
Dresden
Dresden per ha
Amsterd am
PPH
424.00
158.00
232.00
139.00
439.00
Study area (ha)
314.16
314.16
314.16
314.16
314.16
Amste rdam per ha
Primary School (DB)
3.00
0.0095
1.00
0.0032
4.00
0.0127
4.00
0.0127
6.00
0.0191
Secondary School
4.00
0.0127
3.00
0.0095
6.00
0.0191
1.00
0.0032
3.00
0.0095
Community Buildings
8.00
0.0255
8.00
0.0255
17.00
0.0541
5.00
0.0159
0.00
0.0000
Health Centres
8.00
0.0255
2.00
0.0064
6.00
0.0191
5.00
0.0159
6.00
0.0191
Shops, Pubs, Creche
8.00
0.0255
4.00
0.0127
5.00
0.0159
7.00
0.0223
4.00
0.0127
14.00
0.0446
5.00
0.0159
10.00
0.0318
8.00
0.0255
6.00
0.0191
Open Space Parks Total nonresidential per ha
0.1432
0.0732
0.1528
0.0955
0.0796
Applying the open space principle – just the outdoor sports and recreation place,
the study areas should be atleast 25% test areas as opendecades, space to The 21st century home is having evolving andof the over coming is support the population density, however as indicated in the faciltieis plans, this is also not the case. likely to bear little resemblance to the suburban product that we have become so used to in Genoa the 20thSana century. New per Dresden Amsterdam Study areas
Primary school Secondary school Recreation Health Worship Retail Open space Offices / light industry
per ha
ha
York per ha
per ha
per ha
PPH 158 232 study 139cities all 439 The neighbourhoods analyzed in424the chosen case of Study 133203.54 72884.96 43668.14 and 137915.93 have goodPop links toarea retail, leisure and49637.17 education resources faciliOpen Space 79.42 69.87 220.67 ties. We have chosen to study213.13 the cities using116.62 the standard 400m pedestrianPercentage movement zone and 1km wider zone. In each case the of study 67.84 25.28 37.12 22.24 70.24 area should be outdoor neighbourhoods have a range of local facilities and can begin to function as polycentric cores within the wider city. For example our study of Sana’a revealed that the organic street layout and position Portsmouth facilities of public spaces could sustain a certain level of density and intensiTherefore the Portsmouth development with a population of 9650 and a density of fication. 500pph requires a total of 29.52 ha of non-resdential space for the scheme to be
The urban form of case study sites has been tailored to provide certain critical neighbourhood facilities such as schools and convenience stores. In New York city it is common for the ground storey of the tower blocks to have cafes, delicatessens and local shops. This provides the neighbourhood with active ground stories and all day activity and contributes to the bustling urban quality of New York.
51
Case study 3D models with F.A.R. values
Amsterdam, “Berlage” Perimeter block
Dresden, “Wurfelhaus” Urban villa
Genoa, “Town Palace” Courtyard
New York City, “Upper East Side” Tower
Sana’a, “Towerhouse” Townhouse
• 183 dph / 439 pph
• 58 dph / 139 pph
• 177 dph / 424 pph
• 97 dph / 232 pph
• 66 dph / 158 pph
• F.A.R. 265%
• F.A.R. 93%
• F.A.R. 227%
• F.A.R. 1381%
• F.A.R. 326%
models shown with relevant human scale
7.0 CASE STUDIES
Case study efficiency values
Summary
F.A.R. value plot area*
Our study starts at the city levels and develops to the level of the block typology and reveals interesting statistical data on the performance of each development model.
Habitation efficiency value gross internal floor space** F.A.R.
plot coverage
population
habitation efficiency*
plot coverage 100%
population
habitation efficiency*
100% AMSTERDAM AMSTERDAM
AMSTERDAM
DRESDEN DRESDEN 270%
GENOA AMSTERDAM GENOA NYC AMSTERDAM DRESDEN NYC
DRESDEN 90%
SANA'A DRESDEN GENOA SANA'A AMSTERDAM GENOA NYC
GENOA
DRESDEN NYC SANA'A
230%
GENOA SANA'A NYC
NYC SANA'A AMSTERDAM DRESDEN
1380%
439 habitation efficiency* 6.0%
plot coverage population 139 100% 139 plot coverage population
6.0% habitation efficiency* 424 439 424
100%
232 2.7% 439 6.0%habitation efficiency* plot coverage139 population 232 2.7%
SANA'A GENOA NYC
8.2% 8.2%
11.5% 8.2%
11.5%
8.2%
100%
158 2.0% 139 6.0% 158 2.0% * gross population expressed over plot coverage % * gross population expressed 232 2.7% over plot coverage % 139
424 439 424
11.5% 8.2% 11.5%
6.0% 232 2.7% 158 2.0%
* gross population expressed over plot coverage 158 % 2.0%
424
11.5%
* gross population expressed232 2.7% habitation efficiency* plot coverage population over plot coverage % 100% 158 2.0% * gross population expressed 439 over plot coverage % plot coverage population habitation efficiency* 139 6.0% 100%
GENOA AMSTERDAM NYC DRESDEN
SANA'A
439
Our analysis of the Upper East Side tower reveals that the tower model can potentially yield a very high residential area compared to its land take there is a drop off in quality at the street level but also the wider human scale seen both inside the building but also in the streetscape. The disconnection between interior environment and street is stark. In this case the tower on the corner of Lexington Avenue and 78th Street contains only 2 luxury apartments per floor plate. In reality current market forces would drive more efficiency in this model. The resulting FAR at first seems impressive but only delivers a finite number of dwellings.
424 439 139
The Amsterdam super blocks have a lower FAR and yet have a very good habitation efficiency which enables the typology to deliver large numbers of dwellings. The benefit of the Amsterdam typology is that generally good environmental quality is provide to both residents and street alike. The Genoa courtyard blocks have the highest habitation efficiency but reveal a drop off in quality.
8.2%
The key principles that we take from the case studies in terms of performance reveals a dramatic range of densities and dwellings which enables various generic models to be developed. 8.2%
11.5%
232 2.7% 6.0% 158 2.0%
424
11.5%
* gross population expressed over plot coverage % 232 2.7%
330% SANA'A * plot areas vary but are shown at comparable scales ** Floor Area Ratios shown against size of plot
158 2.0% * gross population expressed over plot coverage %
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DRESDEN - URBAN VILLA
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R F O C OM
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SCALE
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Case studies 12 Gehl quality criteria
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GENOA - COURTYARD
AMSTERDAM - PROTECTION
AMSTERDAM - COMFORT CHARLOTTE
V C EL IOL RIM SE EN E / CU CE RE
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CHARLOTTE ANDREW
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MAWGAN
AGREE AMSTERDAM - DELIGHT THESE QUALITIES ARE PRESENT
CHARLOTTE SOME OF THESE QUALITIES ARE PRESENT
ANDREW
DRESDEN - OVERALL R F O C OM
DRESDEN - PROTECTION CHARLOTTE
MAWGAN DISAGREE THESE QUALITIES ARE NOT PRESENT DRESDEN - DELIGHT
DRESDEN - COMFORT
SANA'A - TOWNHOUSE
NEW YORK - TOWER CHARLOTTE
CHARLOTTE
ANDREW
ANDREW
ANDREW
MAWGAN
MAWGAN
MAWGAN
CHARLOTTE
CHARLOTTE
ANDREW
ANDREW
ANDREW
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V C EL IOL RIM SE EN E / CU CE RE FE
MAWGAN
MAWGAN CHARLOTTE
CHARLOTTE
GEHL "12 QUALITY ASSESSMENT" CASE STUDY RESULTS ANDREW HOARE: 39, ARCHITECT
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MAWGAN
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SOME OF THESE QUALITIES ARE PRESENT
SANA'A - TOWNHOUSE
NEW YORK - TOWER
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GEHL "12 QUALITY ASSESSMENT" CASE STUDY RESULTS CHARLOTTE FLEMING: 25, TOWN PLANNER
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ANDREW
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7.0 CASE STUDIES MAWGAN
AVERAGE
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T
SCALE
RT TA UNIT LK ES LIS AND TE N
ES NIT EE TU O S OR T
R F O C OM
C
MAWGAN
PO
P OP
T
OP TO POR AS ENJ TUN PE OY ITIE CT S C POS S LIM ITIV AT E E
ANDREW
OP
S ITE UN RT PO LK OP WA O T
OPPORTUNITES TO SIT
OP TO POR S T ST TUN AY AN D / ITES
OPPORTUNITES FOR PLAY AND EXERCISE
ES NIT EE TU O S OR T
R F O C OM
CHARLOTTE
P OP
OR T TA UNIT LK ES LIS AND TE N
P OP
OPPORTUNITES TO SIT
AVERAGE
NT SA Y EA O R PL N S ES UN SE IENC ER P EX
SCALE
OP P
ES
V C EL IOL RIM SE E N E / CU CE RE
OP TO POR AS ENJ TUN PE OY ITIE CT S C POS S LIM ITIV AT E E
O
OP TO POR S T STA TUN AY N D / ITES
SCALE
FE
T H
I G
D E L
OPPORTUNITES FOR PLAY AND EXERCISE
MAWGAN
TRAFFIC / ACCIDENTS FEEL SAFE
V C EL IOL RIM SE E N E / CU CE RE
T
H
TRAFFIC / ACCIDENTS FEEL SAFE
FE
NT SA Y EA O R PL N S ES UN SE IENC ER P EX
T
I
RO T E
N
I G
O
R F O C OM
T
GENOA - OVERALL GENOA - COURTYARD
DRESDEN - URBAN VILLA
AMSTERDAM - PROTECTION
CHARLOTTE
CHARLOTTE
CL SIT IM IVE AT E
S ITE
DRESDEN - COMFORT
CHARLOTTE GENOA - PROTECTION
V C EL IOL RIM SE EN E / CU CE RE
RT UN IT DRESDENTA-LDELIGHT K ES LIS AND TE N
CHARLOTTE ANDREW
R F O C OM
ANDREW
ANDREW
MAWGAN
MAWGAN
DRESDEN - PROTECTION MAWGAN
DRESDEN - COMFORT CHARLOTTE
CHARLOTTE
ANDREW
ANDREW
ANDREW
GEHL "12 QUALITY ASSESSMENT" CASE STUDY RESULTS MAWGAN PENGELLY: 34, LANDSCAPE ARCHITECTMAWGAN MAWGAN AVERAGE
MAWGAN
AGREE GENOA - PROTECTION THESE QUALITIES ARE PRESENT
T
GENOA - DELIGHT
GENOA - COMFORT CHARLOTTE
CHARLOTTE
SOME OF THESE QUALITIES ARE PRESENT
ANDREW
ANDREW
ANDREW
MAWGAN
MAWGAN
NYC - OVERALL MAWGAN DISAGREE THESE QUALITIES ARE NOT PRESENT
CHARLOTTE NYC - PROTECTION
NYC - DELIGHT
NYC - COMFORT
SANA'A - TOWNHOUSE CHARLOTTE
CHARLOTTE
CHARLOTTE
ANDREW
ANDREW
ANDREW
MAWGAN
MAWGAN
MAWGAN
ANDREW
CHARLOTTE
CHARLOTTE
ANDREW
ANDREW
ANDREW
MAWGAN
MAWGAN
MAWGAN
ANDREW
MAWGAN
MAWGAN NYC - PROTECTION CHARLOTTE
NYC - COMFORT
SANA'A - PROTECTION
NYC - DELIGHT
SANA'A - COMFORT
SANA'A - DELIGHT
CHARLOTTE
CHARLOTTE
CHARLOTTE
ANDREW
ANDREW
ANDREW
ANDREW
ANDREW
ANDREW
MAWGAN
MAWGAN
MAWGAN
MAWGAN
MAWGAN
MAWGAN
AVERAGE
SANA'A - PROTECTION CHARLOTTE
CHARLOTTE
CHARLOTTE
The case studies also have an underlining cultural component which impacts on the quality assessment. This can be compared with traditional UK, US and Australian cities where generally people prefer more space and therefore regard the Genoa model as lower quality. In the Yemen for example it is very desirable to have society mixing within the constraints of an Islamic city and yet the model offers similarities with UK Victorian cities which comparable models of dense living. Our research for this module is deliberately based on an issue driven abstract tool kit which we could legitimately apply to any city to obtain a gauge of environmental quality within the context of increasing intensification.
SANA'A - DELIGHT
SANA'A - COMFORT CHARLOTTE
AVERAGE
The relationship between Dresden and Genoa is interesting for many reasons as it reveals a sharp drop in environmental quality which is most obviously but not exclusively linked to the plot coverage ratio. It would seem that when a site is developed with a FAR approaching 225%-250% and a target population of say 400 then quality drops away. Despite this finding it is still possible to develop FAR ratios in excess of 250% provided the plot coverage is smaller for example as seen in Sana’a and New York. Obviously the typological model is different but the quality is higher than say Genoa courtyards.
DRESDEN - DELIGHT
CHARLOTTE
CHARLOTTE
GENOA - DELIGHT
GENOA - COMFORT
NEW YORK - TOWER CHARLOTTE
PO
MAWGAN
MAWGAN
ANDREW
OP
ES NIT
S ITE E UN SE RT TO
T
OPPORTUNITES FOR PLAY AND EXERCISE
PO
R F O C OM
CHARLOTTE
ANDREW
SA Y EA O R PL N S ES UN SE IENC ER P EX
MAWGAN
U RT PO LK OP WA TO
CHARLOTTE
MAWGAN
O
OP
S ITE E UN SE RT TO
ANDREW
GENOA - OVERALL
MAWGAN
I
AMSTERDAM N-TDELIGHT CHARLOTTE
OPPORTUNITES TO SIT
CHARLOTTE
PO
OPPORTUNITES TO SIT
OP TO POR S T ST TUN AY AN D / ITES
- PROTECTION OP
N TU DRESDEN R PO LK OP WA TO
OP P
OR T TA UNIT LK ES LIS AND TE N
T
ANDREW SCALE
OP TO POR S T STA TUN AY N D / ITES
AVERAGE
ANDREW
OP TO POR AS ENJ TUN PE OY ITIE CT S C POS S LIM ITIV AT E E
ANDREW OPPORTUNITES FOR PLAY AND EXERCISE MAWGAN
SCALE
MAWGAN
CHARLOTTE
AMSTERDAM - COMFORT
C
FE
T H
ANDREW
I G
NT SA Y EA O R PL N S ES UN SE IENC CHARLOTTE ER P EX
D E L
PE OY ITIE CT CHARLOTTE S PO S
O
P R O T E
TRAFFIC / ACCIDENTS FEEL SAFE
I
V C EL IOL RIM SE EN E / CU CE RE FE
TRAFFIC / ACCIDENTS FEEL SAFE
T H
D E L
OP TO POR AS ENJ TUN
T
AMSTERDAM - DELIGHT
AMSTERDAM - COMFORT
CHARLOTTE
N
AMSTERDAM - PROTECTION MAWGAN
C
VE TI Y ES SI O R NC PO N S RIE S E PE EX
I G
P R O T E
N
VE TI Y ES SI O R NC PO N S RIE S E PE EX
ANDREW
The case study cities and typologies each have a unique approach to intensification and all have very different quality receptors. A reading of our analysis reveals that each typology has differing yields of capacity which corresponds to a quality threshold.
DRESDEN - OVERALL P C
VE TI Y ES SI O R NC PO N S RIE S E PE EX
I
P R O T E
N
OP TO POR AS ENJ TUN PE OY ITIE CT S C POS S LIM ITIV AT E E
ANDREW
IT UN RT PO LK OP WA TO
T VE TI Y ES SI O R NC PO N S RIE S E PE EX
D E L
C
N
VE TI Y ES SI O R NC PO N S RIE S E PE EX
CHARLOTTE
R O T E
D E L
AMSTERDAM - OVERALL P
Summary
CHARLOTTE
SANA'A - OVERALL
NYC - OVERALL ANDREW
ANDREW
ANDREW
MAWGAN
MAWGAN
MAWGAN
CHARLOTTE
CHARLOTTE
ANDREW
ANDREW
MAWGAN
MAWGAN
AVERAGE
AVERAGE
55
Amsterdam, “Berlage” Perimeter block
models shown with relevant human scale
Dresden, “Wurfelhaus” Urban villa
Genoa, “Town Palace” Courtyard
New York City, “Upper East Side” Tower
Sana’a, “Towerhouse” Townhouse
7.0 CASE STUDIES
5 case studies conclusions
Summary
• the typologies that scored highest in the Gehl 12 environmental quality analysis were:
The quality audit of the case studies revealed that the Sana’a typology scored the highest and Genoa typology scored the lowest. In our analysis it is not the FAR ratio which triggers quality but rather the population concentration over a tight plot coverage. We call this the ‘herding’ principle which reveals that the balance between an individual’s private space and communal shared space is essential to ensuring quality with increasing densities.
1. Sana’a - Townhouse 2. Dresden - Urban Villa 3. Amsterdam - Perimeter Block
• the typologies that scored highest in the F.A.R. intensification analysis were:
1. New York - Tower 2. Sana’a - Townhouse 3. Amsterdam - Perimeter Block
• environmental quality vs intensification - quality begins to lessen with a varying density value based upon the social / economic and environmental context
The Sana’a townhouse provides model for intensification which allows a certain level of population to be efficiently housed. However there is a comfort ceiling which can be easily exceeded of density is increased too much. The Amsterdam super block provides the capacity to house a very large population in relative comfort. The super blocks provide good levels of shared space for residents with a high degree of privacy.
The relatively density of Sana’a would seem to trigger lower quality and yet this city contains so many of the generic urban design principles which underpin the work of the Urban Design Task Force. In ‘Towards an Urban Renaissance’ the proximity to local services and facilities is the key to ensuring the city is genuinely walkable. The urban form of Sana’a at first glance seems organic and chaotic but on closer analysis the neighbourhood elements are clustered around spikes of intensity. The Sana’a tower/town house has good provision of personal privacy and space and yet is extremely well connected.
The Dresden typology provides good environmental quality through a development model ensures good provision of personal space and space separation. The Striesen district of Dresden is loose • hybrids of these models could create places that are both F.A.R. grain with villas forming perimeter blocks and wide streets. The intensified and yet retain good environmental quality levels minimum suggested FAR %’s as targets to reach 200pph = 150%, nature of the development has sufficient ‘breathing’ space between fellow residents. 500pph = 200% (these figures could change following testing) • private / public open space balance must give more to public space to facilitate higher density
The Amsterdam typology defined by the street also provides a good quality environment and yet has a very high FAR and population. However despite the high population there is no ‘herding’ as the land take is reasonably large and again breathing space is provided. The New York towers provide seemingly limitless yield but there relatively poor habitation efficiency required greater emphasis on vertical solutions. The down side of this is the affect on the street and public realm. The shattered scale of standing close to 70 storey tower is very uncomfortable and the individual almost has little awareness of the size of the building beyond 4-7 stories. The presence of towers within the urban pattern needs carefully attention as problems of visual connection and ground storey activity can result.
57
8.0 Design Models
“model: an example or pattern that people might want to follow, a theoretical description of the way a system or process works” “Colins English Dictionary”
The purpose of this section is to apply the case study findings to a developing generic model at the given density levels. This will enable further analysis of the spatial implications of the varying densities and scales
59
Design model expanded This next stage sees the case study models refined for use in a generic model showcasing the principles of environmental quality and intensification. This process will involve the 5 typologies from the case studies (Figure 8.1) being pushed and pulled, extruded or shrunk - forming new shapes and hybrids, that fully respond to the module issue. Sketch ideas for this development, as well as additional ways to make land use more efficient can be seen in Figure 8.2.
Perimeter block
Urban villa
Courtyard block
Tower
Townhouse
Figure 8.1 - Case study typologies
Figure 8.2 - Sketch ideas
5 Case Studies
8.0 DESIGN MODELS
5 Generic Typologies Expanded
Further development The generic blocks can be altered in scale and some elements of other types of form to make the land use more efficient whilst retaining a good level of environmental quality. However, it became clear to the group that certain typologies could be combined, in the form of hybrid models, which could offer much better land efficiency and environmental quality. These next pages show the development of that modeling and the revised F.A.R. values that were achieved (Figures 8.3 and 8.4).
Perimeter Block Typology
Urban Villa Typology
Courtyard Block Typology
FAR- 151%-369%
FAR- 76% - 169%
FAR – 121%-533%
FAR (Floor Area Ratio) Gross Internal Floor Area Site Area Ratio = Intensification factor
Tower Typology
Tower/Town House
FAR – 600%-1200%
FAR – 170% - 216%
Figure 8.3 - Generic typologies analysed and recomposed, with relevant F.A.R values
Figure 8.4 - Generic typologies combined into hybrid models
61
F.A.R. hybrid model principles Tower Typology FAR 2400% 24 storey Site Area: 175 sq m Net Residential Area: 4200 sqm Plot Coverage: 100%
Perimeter Block Typology
Habitable Rooms: 52 DPH: 2971 PPH: 7131
FAR 231% 5 storey Site Area: 6445 sq m Net Residential Area: 14910 sqm Plot Coverage: 46% Habitable Rooms: 186 DPH: 288 PPH: 547
Podium Tower Typology FAR 296% 5+24 storey Site Area: 6445 sq m Net Residential Area: 19110 sqm Plot Coverage: 46% Habitable Rooms: 238 DPH: 369 PPH: 886
Podium Tower Typology Option 1 (+2 x2)
Podium Tower Typology Option 2 (-2 x4)
Podium Tower Typology Option 3 (-2 x 1 mega)
FAR 416%
FAR 247%
FAR 373%
+2 perimeter block stories x2 Tower blocks
-2 perimeter block stories x4 Tower blocks
-2 perimeter block stories x1 Mega Tower
7storey perimeter +17 x2 storey tower
3 storey perimeter +10 x4 storey tower
3 storey perimeter +32 storey tower
Site Area: 6445 sq m Net Residential Area: 26824 sq m Plot Coverage: 46%
Site Area: 6445 sq m Net Residential Area: 15946 sq m Plot Coverage: 46%
Site Area: 6445 sq m Net Residential Area: 24050 sq m Plot Coverage: 46%
Habitable Rooms: 335 DPH: 519 PPH: 1247
Habitable Rooms: 199 DPH: 308 PPH: 741
Habitable Rooms: 465 DPH: 308 PPH: 1117
(left) SITRA programme by REX architecture (source: www.rex-ny.com) !"#$%&'()*"+,"-.&/$0.$%11(&& 2%#3%4%%$"&5(+4"-3"&6"-+%-,& 78&'9:&;$<="#(#<*$(&
8.0 DESIGN MODELS
Neighbourhood model The key structuring elements at a neighbourhood scale that can be transferred to a site are defined at a conceptual level by 12 Jan Gehl quality criteria. Our conceptual city will feature all 12 aspects (to varying degrees) in order to safeguard quality.
Neighbourhoods such as these exist in abundance in every town, although the degree to which they match the ideal model is dependent upon a number of influences such as decisions to rationalise school and service provision or the loss of a major employer. They also represent a past investment that is capable of being exploited and enhanced in preference to abandonment and re-provision elsewhere. Most neighbourhoods contain deficiencies of one sort or another and new development will provide one Layer 1 -and Urban centre opportunity to help remedy this, making them more viable sustainable in the process (see Context Appraisal Methodology on page 18). These 50 ha clusters of existing or potential urbanity are referred to as 0m 80 ‘Units of Sustainability’ within this guidance.
Within Neighbourhoods, only the following Development Types shall The sketch layouts developed for the 200 PPH and 500 PPH modapply: els include a range of spaces and details described by Gehl. For inCompact Development (see page 124) stance the street network is well connected and leads to a range of Image 92 Robust Urban Form (see page 125) urban spaces that can support a vibrant range 116 of activities. Figure Urban Centre Small Infill (see page 126) 8.5 illustrates how the neighbourhood scale is built up, through a series of layers, but all focusing on the human scale of the development. Neighbourhoods m
400m
Layer 4 - Large urban infill site
Image 95
117
Large Urban Infill site
119
Large Urban Infill
Occasionally, development opportunities arise on large urban sites. These may have once been in institutional use for instance and, provided these 400m 0 sites are at least 50 ha in size, they are capable of being developed as 40 Most traditional towns in Essex developed in an outward pattern along the sustainable urban infill containing a mixed-use centre, space for Smallmain Urban InfillSuburbs were laid out with walking in mind and radial, streets. 0m good access to public transport with close proximity to employment, services and schools and a compact residential community. frequently combined 40 within Opportunities exist every town to build within small urban gaps that If a site contains buildings, their potential for retention and re-use should be Key neighbourhood principles important services, schools At and shops, a compactcompletes residential are not required for such otheras purposes. best, suchand development examined within any Context Appraisal and there should always be a catchment nearby. They were, and mainly still represent, a unit of liveability Image 93 the continuity of frontage of a street and removes a local eyesore. The presumption for retaining the better buildings that exist. that is a good model of a sustainable physical limitation of available site areacommunity. imposes particular challenges for centres Neighbourhood Layerin2a -larger Neighbourhood centres Layer 5 - Sustainable urban extension town (left) If less than 50 ha in area, the development type will be determined by the designer but the of the advice contained within this guidance Athe neighbourhood unitprovisions can be considered to 0be around 50 hectares within an m 0 and small urban centre 4 • A hierarchy of centres - neighbourhood centres based around area ‘fit’ of the site to the other scenarios in Diagram 5 (see page 123). Like all still apply. For it is still possible for a represents single building to contain a scribed byinstance, a circle of 400m radius which a(below) 5 minute, the spatial criteria scenarios, it is essential for a large urban infill site to be non-residential use on the ground floor,able-bodied to incorporate a rainwater walking distance for most people. It should ideally 400m/5 minute walking distances for key facilities, connections, comfortable capable of being adequately connected to its surroundings via a network of harvesting system with storage, have anofexcellent contain a compact and underground varied housing stock, to a variety greenspace from and public transport usage, and urban centres at 800m with larger parks environmental performance andhealth to accommodate biodiversity within the streets, footpaths, cycleways and green links and that its centre be wellto small squares, shops, and learning facilities and sufficient 0m m structure. served by public transport. commercial and civic uses 00 choice of employment to satisfy many40needs. Although the 400m and 4800m radii represent a 5 minute and 10 minute walk for most people, in practice theWithin streetthese system is likely to make the journey from perimeter centre situations, only the following Development Typetoshall Within these situations, only the following DevelopmentImage Type shall 96 longer and convoluted. Nevertheless, the use of a measured radius has the apply: apply: Sustainable Urban benefit of simplicity and inclusion of all land that has potential for adding to • New development should make a contribution to creating an Extension Small Infill (see page 126) Large Sustainable Development (see page 125) 121 Image 97 integrated open space or green network, including the street, ratherthe sustainability of the location.
than parks and squares at key junctions.
118
Assembled town diagram and small urban centre
Within these situations, only the following Development Type shall 400m apply: 3 Large Sustainable Development (see page 125)
• Commercial uses placed at urban centres, with smaller mixed uses spaced around the 400m radius. Uses must respond to the needs of the context.
4
400m
Layer 3 - Small urban infill sitesSites beyond these locations
• Residential units increase in density towards neighbourhood and urban centres, although the use of tall buildings must be assessed from a street level view, taking into account sun path studies. • For higher densities, public open space can be increased by reducing private open space, clutter from the street and placing car parking areas behind or under the building.
Assembled town diagram m
0 122 It is important not to seek high density development 40 on land that is poorly
0m public transport. connected to other places80by Doing so increases the 2 5 number of unnecessary journeys made by car, adding to local traffic 1 and carbon emissions. These developments represent congestion, pollution 0m 0m and have the least potential 40 for those parts of an urban area that are not, 5 40 2 2 becoming, sustainable communities. In these situations it would be expected that densities would be below 50 dph.
Image 94 Small Urban Infill sites
Figure 8.5 - 5 layers of neighbourhood model combined - not to scale (source “The Urban Place Supplement”, Essex Design Guide, 2007)
1. 2. 3. 4. 5.
Urban centre Neighbourhood /small urban centre Sustainable urban extension Large urban infill Small urban infill
Railway station Green space Bus route
63
9.0 Test Site
on the City of Portsmouth - “too full of drugs, obesity, underachievement and Labour MP’s” Boris Johnson, Mayor of London
This section examines a test site for the application of the generic models and concepts. Following assessment of the site as it currently is, the density proposals for the chosen site will be illustrated through two 3D master plans
65
Chosen site - Ravelin Park, Portsmouth Portsmouth is unique on the south coast of England, in that it is a densely populated urban area, but also very compact. This means that potentially the City is walkable, but sadly that is not the case at the moment due to poor quality public realm and many physical and non-physical barriers when moving through the space. The history of Portsmouth is synonymous with The Royal Navy and its Dockyard in the City - the home of the oldest dry dock in the world, built by Henry V in the 15th Century. To this day a tenth of the cityâ&#x20AC;&#x2122;s workforce work there, with other linked technological industries setting up in the surrounding areas (BAE Systems). Yet the future of the naval dockyards and the size of the UK Naval Fleet is reducing year-upon-year. The group believes the substantial land area in Portsmouth owned by the Navy is now inefficient, especially in a dense city. The group therefore feels that choosing a site currently in owner ship of the Navy is forward thinking. The chosen site area is called Ravelin Park, shown right in both map and aerial form. Currently the site is mainly used as a sports facility/grounds by the Navy, surrounded by security fencing. Due to cut backs in funding, and advances in technology, there have been talks to relocate the sports usage over to the main Navy base in Portsmouth.
Site boundary 19.3ha
Figure 9.1 - Contextual location of Portsmouth within the UK
Existing site plan 1:5000 (source: OS mapping)
9.0 TEST SITE
The wider context of the site offers two train stations within walking distance to the north, the Gunwharf Quays shopping centre to the west, and a Southsea Common, a large area of open space to the south.
Queen Street Victoria Park
In addition to rail links (which connect to London stations and Southampton Airport), there are good road links via the A3 Spine Road and A2030 Link Road. Through recent development, including Gunwharf and the Spinnaker Tower, the site is surrounded by a combination of tall buildings and dense impermeable residential areas.
Portsmouth & Southsea Station
Portsmouth Harbour Station
A key city spine runs through the centre of the site, which is criscrossed to form 3 large parcels of land. The overall site area for Ravelin Park is 19.3 ha. Gunwharf Quays A2030 Link Rd
At 19.3 ha in size, the group can begin to workout the density requirements: Therefore 200pph = 3860 A3 Spine Rd
Therefore 500pph = 9650 200pph / 83dph =
1601 units
500pph / 208dph =
4014 units
The group will now assess the site â&#x20AC;&#x153;as isâ&#x20AC;?, using the Gehl 12 quality criteria, facilities study and site analysis plans.
Site boundary 19.3ha Existing aerial plan 1:5000 (source: Google maps)
67
Ravelin Park local facilities
1km radius
The Ravelin Park scheme, with a population of 9650 and a density of 500pph requires a total of 29.52 ha of non-residential space for the scheme to be in keeping with UK guidance. According to the guidance with a density of 500pph 15.55ha of outdoor space needs to be provided, and 7.72 ha for childrenâ&#x20AC;&#x2122;s play. Overall 52.79ha of non-residential use needs to be provided to comply with the guidelines (excluding any infrastructure requirements) to provide a sustainable development site with a density of 500pph, however the Portsmouth site is only 19.3 ha and doesnâ&#x20AC;&#x2122;t have the capacity to provide enough non-residential uses for a 500pph density scheme. As well as uses, a site needs to be well connected and have the correct infrastructure, such as being within 200m of a bus stop. Portsmouth Harbour and Portsmouth and Southsea Railway stations are just over 1km away along with an International Ferry Port located to the North of the site. Due to these non-residential facilities problems, we have developed stackable and mixed use non-residential uses on the site, yet not all uses can be stacked - some of the non-residential uses have to be allocated off site, within a 400m or 1km walking distance, such as Southsea Commmon and waterfront and Gunwharf Quays retail outlet.
Primary school Secondary school Recreation Health Worship Retail Open space Offices / light industry
Figure 9.2 (right) - Portsmouth facilities plan - not to scale
400m radius
9.0 TEST SITE
Ravelin Park Gehl 12 quality criteria and analysis The analysis drawing shown in Figure 9.4 is a sketch analysis of the site, showing the group’s initial responses. It is important to highlight the spine road that runs through the site, as well as teh proximity to other land uses / facilities, including 2 train stations, a large commercial centre (Gunwharf Quays) and a large area of open space (Southsea Common). The number of tall or landmark buildings that surround the site area are also highlighted, as well as key nodal spaces or gateways. The group also assessed the site (as a whole) through the use of the Gehl 12 point quality criteria colour wheel, which can seen in Figure 9.3. Although the group recognises that one assessment for a site this large is not ideal, it does however raise clear issues, especially with the sections under “protection” and “comfort”.
Site boundary Key space / gateway Impermeable space Tall / landmark building Figure 9.3 - Ravelin Park 12 Gehl quality assessment (group average)
Key city spine Figure 9.4 - Ravelin Park analysis (not to scale)
69
SiteApplication Application- -Ravelin RavelinPark ParkPortsmouth Portsmouth Site Site Application - Ravelin Park Portsmouth Site Site Application Application - Ravelin - Ravelin Park Park Portsmouth Portsmouth neighbourhoodstructuring structuringelements elements • •neighbourhood Site Site Application Application - Ravelin - Ravelin Park Park Portsmouth Portsmouth • neighbourhood structuring elements • neighbourhood • neighbourhood structuring structuring elements elements • neighbourhood • neighbourhood structuring structuring elements elements Ravelin Park structuring elements
MainNetwork NetworkofofStreets Streets Main PublicTransport Transportand andNodes Nodes Public
PedestrianAccessibility Accessibility Pedestrian
Main existing movement pattern Main existing movement pattern Public Transport and Nodes Public Public Transport Transport and and Nodes Nodes Public transport and nodes Public Public Transport Transport andand Nodes Nodes Main existing movement pattern Main Main existing existing movement movement pattern pattern
Movement hubs andrange range Movement hubs and Pedestrian Accessibility Pedestrian Pedestrian Accessibility Accessibility Pedestrian accessibility Pedestrian Pedestrian Accessibility Accessibility Movement hubs and range Movement Movement hubs hubs and and range range
• Main existing movement patterns
Main Main existing existing movement movement pattern pattern
Block and Street layout Block and Street Main street network Main Network oflayout Streets Main Main Network Network of of Streets Streets • Block and street layout Main Main Network Network of Streets oflayout Streets Block and Street layout Block Block and and Street Street layout Block Block andand Street Street layout layout
• Movement hubs and range
Movement Movement hubs hubs andand range range
Density model
DensityModel Model Density Density Model Density Density Model Model Density Density Model Model
Thegreenspace/waterspace greenspace/waterspacesystem system The
LandUse UsePattern Patternand andDensity Density Land
Key elements criticaltotolocal localsystem Key elements critical The greenspace/waterspace The The greenspace/waterspace greenspace/waterspace system system
Intensity gradient and form Intensity gradient and form Land Use Pattern and Density Land Land Use Use Pattern Pattern and and Density Density Land use pattern and density • Intensity gradient and form Land Land Use Use Pattern Pattern and and Density Density Intensity gradient and form Intensity Intensity gradient gradient and and form form
The green space / water space system environment •environment Key elements critical to local environment system The The greenspace/waterspace greenspace/waterspace system
Key elements critical to to local Key Key elements elements critical critical to local local environment environment environment Key Key elements elements critical critical to local to local
Intensity Intensity gradient gradient andand form form
Block pattern
BlockPattern Pattern Block
9.0 TEST SITE
Ravelin Park site photos
71
Facility requirements
Portsmouth policy summary
Facilities Cities canrequirements not just function off residential alone, facilities such as employment, shops, recreation space places of employment, worship also Cities can not just function off residential alone,and facilities such as Facilities requirements shops, space and places of also needThe to beprovision included to of make it need torecreation be included to make it worship sustainable. nonsustainable. The provision of non-residential facilties depends on the ammount residential facilities depends on the amount and demographic of the Cities can function dwellings, off residential alone, facilities such as employment, and demographic of not thejust proposed additinally the location of the site in shops, recreation space and places of worship also need to be included to make it proposed dwellings, thedistance, location of the in relation relation to other facilities additionally within a walkable of 400m or site 1km (as defined to sustainable. The provision of non-residential facilties depends on the ammount by ***) and demographic of the proposed dwellings, additinally the location of the other facilities within a walkable distance, of 400m or 1km. site in
Portsmouth City Council has 12 objectives to their Development Plan for the City (adopted January 2012):
relation to other facilities within a walkable distance, of 400m or 1km (as defined
by ***) Total Site area = 19.3ha
Total Site area = 19.3ha Total Site area = 19.3ha
Population at 500 pph = 500 x 19.3 = 9650 pop Population at 500 pph = 500 x 19.3 = 9650 pop
Population pph = =500 x units 19.3 = 9650 pop Units at 500 at pph500 = 9650/2.4 4020 Units at 500 pph = 9650/2.4 = 4020 units Units at 500 pph = 9650/2.4 = 4020 units Population at 200 pph = 200 x 19.3 = 3860 pop PopulationPopulation at 200 atpph = 200 3860 200 pph = 200xx 19.3 19.3 = = 3860 pop pop Units 200 pph= 3860/2.4 = =1608 units Units at at 200 pph= 3860/2.4 = 1608 units Units at 200 pph= 3860/2.4 1608 units Average age distribution on the site Average age distribution on the site
Average age distribution on the site Density
Pop.
0 to 4
nsity
Pop. 0 to 4 5 to 7 UK % of 5.96 population % of 2001 census 5.96 3.74 ulation 9650 575 1 census 500 pph pph pph
200 pph
9650 3860
3860
575
230
361
5 to 7
8 to 11
8 to 11 3.74 361 144
12 to 16 5.24
5.24 505
12 to 16
505 202
17 to 18
17 to 18 6.46
6.46 623
623 249
20 to 64
65+
20 to 64
2.46
2.46
237 95
237
65+
60.25
60.25
15.89
15.89
5814
1533
2326
613
5814
230 to Burns 144 2012 a neighbourhood 202 249 95requires the 2326 According of 8-10,000 people following non-residential facilities:
1533 613
According to Burns 2012 a neighbourhood of 8-10,000 people reAccording to Burns 2012 a neighbourhood of 8-10,000 people requires the Number Area Required Total Area quires thenon-residential following non-residential facilities: following facilities: Primary School 3 Secondary School Number1 Community Buildings 1 Health Centres 1 Primary School 3 Shops, Pubs, Creche Secondary School 1 TOTAL NON Community RESIDENTIAL Buildings 1
(ha) 0.5 Area 3.6 Required (ha) 0.2 0.25 0.5 0.7
(ha) 1.5 3.6 Area Total 0.2 (ha) 0.25 1.5 0.7 3.6 6.25
3.6 0.2 0.2 Health Centres 1 0.25 0.25 Add to non-residential buildings the requirement for open space,0.7 which also Shops, Pubs, Creche 0.7 TOTAL NON creates a ‘good place’. Fields in Trust 2011 ‘6 Acre standard’, suggests 6.25 that an extra 1.6 hectares (per 1000 residents) needs to be provided for outdoor sport RESIDENTIAL and recreation space (including parks), 0.55ha (childrens play) and 0.25 ha (equipped playgorounds) therefore with a density of 500pph 15.55ha of outdoor space needs to be provided, 7.72 ha for for childrens Add to non-residential buildings the and requirement openplay. space, which also creates a ‘good place’. Fields in Trust 2011 ‘6 Acre standard’, suggests that an Add to non-residential buildings the requirement for open space, extra 1.6 hectares (per 1000 residents) needs to be provided for outdoor sport which alsoCase creates a ‘goodparks), place’. Fields in Trust ‘6 Acre and recreation space (including 0.55ha (childrens play)2011 and 0.25 ha Study facilities (equipped playgorounds) therefore with a density of 500pph 15.55ha of outdoor standard’, suggests that an extra 1.6 hectares (per 1000 residents) space needs to be provided, and 7.72 ha for childrens play.
needs to be provided for outdoor sport and recreation space (including parks), 0.55ha (children’s play) and 0.25 ha (equipped playgrounds) therefore with a density of 500pph 15.55ha of outdoor Case Study facilities space needs to be provided, and 7.72 ha for children’s play.
1. 2. 3. 4. 5. 6. 7. 8.
To make Portsmouth an attractive and sustainable city To make Portsmouth an accessible city with sustainable and integrated transport To develop Portsmouth as a city of innovation and enterprise, with a strong economy and employment opportunities for all To make Portsmouth a city in which everyone feels and is safe To deliver affordable / quality housing where people want to live To encourage and enable healthy choices for all and provide appropriate access to health care and support To enhance Portsmouth’s reputation as a city of culture, en- ergy and passion offering access for all to arts, sport and leisure To ensure there is adequate supporting infrastructure for the new development and growth of the city
correct density on the site, and linking the high rise and dense older City Centre with the modern high rise and dense Gunwharf Quays. To the East of the project site is the Somerstown ward of the city which is being redeveloped with an Area Action Plan, our project site can conveniently be an extension to the area redevelopment plan. Within the city centre the council aims for a minimum density of 100dph (240pph) (policy PCS21 – Housing Density). With 1.5ha of open space being provided per 1,000 population (Policy PCS13 – Greener Portsmouth) therefore with a density of 500pph therefore 4.6% of the land use on the site should be allocated green space. Policy PCS14 (Healthy City) and PCS17 (Transport) also requires facilities such as health facilities, schools and retail to be within a 10 minute walk or public transport trip of the site. It is thought that our development model complies with these policies with schools, doctors and major transport hubs just over 400m from the project site.
These 8 objectives help us see that the city is striving to achieve exThe project site is surrounded by Conservation areas, and several cellent and sustainable development on a very restricted land mass, listed buildings and walls fall within the site, therefore these builddue to the city being surrounded on three sides by the sea, meaning ings and features need to be retained and special care taken so carefully land management. that the development is keeping with the character of the protected features. Our test site hopes to help Portsmouth achieve these targets. With a target density of 500pph this would provide 4020 dwellings in the city (averaging 2.4 people per unit), helping the Council to achieve the extra 7,117-8,387 dwellings in the city between 2010-2027 (Policy PCS10 – Housing Delivery), and providing much needed family housing to the area. Bordering the site to the North, land is allocated as High Density development area and suitable for Tall buildings (above 6 storeys) Although our concept models have a flexible design, it is thought that development should try to fit in with surround area and policies wherever possible, so keeping taller buildings to the North of the Site and just extending the policy allocation area to include our site would be considered the most appropriate method of achieving the
9.0 TEST SITE
Site Application 200pph â&#x20AC;˘ Density Modelling Net Residential Area: 126,625 sq m Net Non Residential Area: 84,750 sq m Site Area: 19.3 ha Development Area: 10.9 ha Average FAR: 116%* *density gradient to be applied across entire site
Urban Design Issues 1 Ravelin Park, Portsmouth Site Area (hectares) 19.3 Density (DPH) 83.37 Capacity (PPH) 200.08 Total Population 3861.6 Use Typology Net Area Urban Design Issues 1 Ravelin Park, Portsmouth Site Area (hectares) 19.3 Density (DPH) 83.37 Capacity (PPH) 200.08 Total Population 3861.6
(sq m per unit) Residential Residential Residential Residential Residential Residential Residential Residential Non Residential Commercial Community Retail Recreation Infrastructure
Use
Typology 125
Town House (4b 7P) Town House (5b 7P) Apartments (1b) Apartments (2b 3P) Apartments (2b 4P) Apartments (3b 5P) Apartments (4b 6P)
Residential Residential Residential Residential Residential Residential Residential Residential Non Residential Commercial Community Retail Recreation Infrastructure
140 51 66 77 93 106
Quantum (total units) 75 75 350 350 450 50 250
Town House (4b 7P) Town House (5b 7P) 1500 2 Apartments (1b) 750 1 Apartments (2b 3P) 2 1000 4500 Apartments (2b 4P) 2 35000 2 Apartments (3b 5P) Apartments (4b 6P) Total Resi 1609 Total Non resi Total
Sub Total (sq m)
Sub Total (ha)
Net Area 9375 10500 (sq m per unit) 17850 23100 34650 4650 26500
125 140 513000 750 662000 779000 70000 93 106 126625 84750 211375
1500 750 1000 4500 35000
0.9375 1.05 1.785 2.31 3.465 0.465 2.65 0.3 0.075 0.2 0.9 7
12.6625 8.475 21.1375
Total Resi Total Non resi Total
Quantum (total units)
Sub Total (sq m)
Sub Total (ha)
75 75 350 350 450 50 250
9375 10500 17850 23100 34650 4650 26500
0.9375 1.05 1.785 2.31 3.465 0.465 2.65
2 1 2 2 2
3000 750 2000 9000 70000
0.3 0.075 0.2 0.9 7
1609
126625 84750 211375
12.6625 8.475 21.1375
48000 263%
4.8
Development Area FAR
Figure 9.5 - Site area / plot coverage comparison
Site application 500pph â&#x20AC;˘ Density Modelling
Net Residential Area: 315,045 sq m Net Non Residential Area: 84,750 sq m Site Area: 19.3 ha Development Area: 10.9 ha Average FAR: 289%* *density gradient to be applied across entire site
Urban Design Issues 1 Ravelin Park, Portsmouth Site Area (hectares) 19.3 Density (DPH) 208.50 Capacity (PPH) 500.39 9657.6 UseTotal Population Typology Net Area Urban Design Issues 1 Ravelin Park, Portsmouth Site Area (hectares) 19.3 Density (DPH) 208.50 Capacity (PPH) 500.39 Total Population 9657.6
(sq m per unit) Residential Residential Residential Residential Residential Residential Residential Residential Non Residential Commercial Community Retail Recreation Infrastructure
Use
Town House (4b 7P) Town House (5b 7P) Apartments (1b) Apartments (2b 3P) Apartments (2b 4P) Apartments (3b 5P) Apartments (4b 6P)
Residential Residential Residential Residential Residential Residential Residential Residential Non Residential Commercial Community Retail Recreation Infrastructure
Typology 125 140 51 66 77 93 106
Quantum (total units) 85 85 425 1225 1225 550 420
Town House (4b 7P) Town House (5b 7P) 1500 Apartments (1b) 2 750 1 Apartments (2b 3P)2 1000 4500 Apartments (2b 4P)2 35000 2 Apartments (3b 5P) Apartments (4b 6P) Total Resi 4024 Total Non resi Total
Sub Total (sq m)
Sub Total (ha)
Net 1.0625 10625Area 11900 (sq m per unit)1.19 2.1675 21675 80850 94325
125 51150 44520 140 3000 51 750 66 2000 9000 77 70000 93 106 315045 84750 399795
1500 750 1000 4500 35000
8.085 9.4325 5.115 4.452 0.3 0.075 0.2 0.9 7
31.5045 8.475 39.9795
Total Resi Total Non resi Total
Development Area FAR
Quantum (total units)
Sub Total (sq m)
Sub Total (ha)
85 85 425 1225 1225 550 420
10625 11900 21675 80850 94325 51150 44520
1.0625 1.19 2.1675 8.085 9.4325 5.115 4.452
2 1 2 2 2
3000 750 2000 9000 70000
0.3 0.075 0.2 0.9 7
4024
315045 84750 399795
31.5045 8.475 39.9795
48000 656%
4.8
73
Ravelin Park, 200pph master plan
400m radius
Local centre
Primary school Secondary school
200pph master plan 1:5000 scale
Smaller mixed uses are spaced around the scheme, but many facilities are available in contextual locations, such as Gunwharf Quays
9.0 TEST SITE
Townhouses
Site Application 200pph
Perimeter blocks
Open space
Urban villas
â&#x20AC;˘ Density Modelling Net Residential Area: 126,625 sq m Net Non Residential Area: 84,750 sq m Site Area: 19.3 ha Development Area: 10.9 ha Average FAR: 116%* *density gradient to be applied across entire site Urban Design Issues 1 Ravelin Park, Portsmouth Site Area (hectares) 19.3 Urban Design Issues 1 Density (DPH) 83.37 Ravelin Park,(PPH) Portsmouth 200.08 Capacity Site Area (hectares) 19.3 Total Population 3861.6 Density (DPH) Capacity (PPH) Use Total Population
83.37 200.08 Typology 3861.6
Residential Use
Typology
Residential Residential Residential Residential Residential Residential Residential Residential Residential Residential Residential Residential Residential Residential Non Residential Residential Commercial Non Residential Community Commercial Community Retail Retail Recreation Recreation Infrastructure
Town House (4b 7P) Town House (5b 7P) Town House (4b(1b) 7P) Apartments Town House (5b(2b 7P) 3P) Apartments Apartments (1b) Apartments (2b 4P) Apartments (2b 3P) Apartments (3b 5P) Apartments (2b 4P) Apartments (4b 6P)
Infrastructure
Apartments (3b 5P) Apartments (4b 6P)
Net Area (sq m per unit) Net Area 125 (sq m per unit)
Quantum (total units) Quantum 75 units) (total
Sub Total (sq m) Sub Total 9375 (sq m)
Sub Total (ha) Sub Total 0.9375 (ha)
140
75
10500
1.05
125 51 140 66 51 77 66 93 77 106 93 106
75 350 75 350 350 450 350 50 450 250 50 250
9375 17850 10500 23100 17850 34650 23100 4650 34650 26500 4650 26500
0.9375 1.785 1.05 2.31 1.785 3.465 2.31 0.465 3.465 2.65 0.465 2.65
750 1500 750 1000 1000 4500 4500 35000 35000
21 12 22 22 2
750 3000 750 2000 2000 9000 9000 70000 70000
0.075 0.3 0.075 0.2 0.2 0.9 0.9 7 7
Total Resi Total Resi Total Non Total Non resiresi Total Total
1609 1609
126625 126625 84750 84750 211375 211375
12.6625 8.475 8.475 21.1375 21.1375
48000 263%
4.8
1500
Development Area FAR
2
3000
0.3
12.6625
A full text review of these proposals can be found in the Conclusions section.
200pph master plan 3D views not to scale
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Ravelin Park, 500pph master plan
400m radius
Local centre
Primary school (2 storey) Secondary school (2 storey)
500pph master plan 1:5000 scale
Smaller mixed uses are spaced around the scheme, but many facilities are available in contextual locations, such as Gunwharf Quays
9.0 TEST SITE
Podium tower
Site application 500pph
Tower
Open space
â&#x20AC;˘ Density Modelling
Perimeter block Net Residential Area: 315,045 sq m Net Non Residential Area: 84,750 sq m Site Area: 19.3 ha Development Area: 10.9 ha Average FAR: 289%* *density gradient to be applied across entire site Urban Design Issues 1 Ravelin Park, Portsmouth Site Area (hectares) 19.3 Density (DPH) 208.50 Urban Design Issues 1 Capacity (PPH) Ravelin Park, Portsmouth 500.39 Site Area (hectares) 19.3 Total Population 9657.6 Density (DPH)
208.50
Capacity (PPH) Use
500.39 Typology
Total Population
Residential Use Residential Residential Residential Residential Residential Residential Residential Residential Residential Residential Residential Residential Residential Residential Non Residential Residential Commercial Non Residential Community Commercial Retail Community Recreation Retail Infrastructure Recreation Infrastructure
9657.6
Typology
Town House (4b 7P) Town House (5b 7P) Apartments Town House (4b(1b) 7P) Apartments Town House (5b(2b 7P)3P) Apartments (1b) Apartments (2b 4P) Apartments (2b(3b 3P) 5P) Apartments Apartments (2b(4b 4P) 6P) Apartments Apartments (3b 5P) Apartments (4b 6P)
Net Area (sq m per unit)
Quantum (total units)
Sub Total (sq m)
Net Area 125 (sq m per unit)
Quantum 85 (total units)
Sub Total 10625 (sq m)
Sub Total 1.0625 (ha)
51150 44520
2.1675 1.0625 8.085 1.19 2.1675 9.4325 8.085 5.115 9.4325 4.452 5.115 4.452
750 3000 2000 750 9000 2000 9000 70000 70000
0.075 0.3 0.2 0.075 0.9 0.2 7 0.9 7
140 51 125 66 140 51 77 66 93 77 106 93 106
1500 750 1500 1000 750 4500 1000 4500 35000 35000
Total Resi
Total Resi Total Non resi Total Non resi Total Total
Development Area FAR
85 425 85 1225 85 425 1225 1225 550 1225 420 550 420
2 21 12 22 22 2
4024
4024
11900 21675 10625 11900 80850 21675 94325 80850 51150 94325 44520 3000
315045
Sub Total (ha)
1.19
0.3
Courtyard block
31.5045
315045 84750 84750 399795 399795
31.5045 8.475 8.475 39.9795 39.9795
48000 656%
4.8
500pph master plan 3D views not to scale
A full text review of these proposals can be found in the Conclusions section.
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10.0 Conclusions
The purpose of this section is to present the findings of our study, and re-assess the process that led to this point. Topics will be suggested for the Issues II Module, and a response will be given to the presentation version of this report
79
Verona, Italy (source: http://gehlcitiesforpeople.dk/)
10.0 CONCLUSIONS
Presentation response
Conclusions
The feedback from the group presentation at the end of October was generally good. Apart from some criticisms of the speed of the presentation, the majority of comments were positive, especially as the group had looked at the issue from the inverse direction from most other groups, from the smallest scale upwards, rather than a “top view” city plan starting point.
Alternatives to sprawl?
This was the entire purpose of our research, to view the issue from a human perspective and scale.
work of Jane Jacobs and Jan Gehl corrects this failing and offers a model of intensification yet still delivers good urban situations. The human scale is back on the agenda.
“compact building and reduced resource consumption need to be discussed in conjunction with requirements for architectural quality”
Through the design and examination of selected case studies in various communities across the developed world a picture emerges of what intensification can look like. The aim of our research is to develop a conceptual model that can function as a basis for development to any site (in this case Portsmouth).
Compact model
Poul Baek Pedersen Our presentation did not feature enough emphasis on the neighbourhood scale of the model, or any 3D renderings of the Portsmouth schemes. These topics have now been addressed in this report.
With urban areas growing fast what are the alternatives to sprawl with consumers increasingly asking for suburban ideals. How does the garden city movement translate into the needs of the 21st century if at all? This project investigates alternatives to spread and sprawl with its demands on resources and energy. These models with their low densities and diffuse grains are considered unsustainable. Our response to the topic question introduces a compressed and heterogeneous urban model with the intention of developing a conceptual approach to the city and resulting typologies which offer a compact model of intensification. In addition our conceptual approach is based on a quality model to safeguard quality in the urban realm. By building in concepts developed by Jan Gehl (see quality assessment) we are able to propose models which deliver the required capacity on a test site and yet can demonstrate elements of good place making. The models developed during the 1950s and 1970s’ were largely taking the work of Le Corbusier and applying different versions of the Unite de Habitation prototype to cities ranging from London, Seattle, Melbourne and Rangoon. In most cases the site application failed to deliver the environmental quality which had been one Le Corbusier key aims. The failure of the object building model of intensification was the disconnection of human scale and place. The
“streets thick with people going to and from their homes, pausing for a chat or just passing through. Streets with rows of front doors and bay windows, balconies and roof terraces. Corner shops, pubs and odd factories. A club under the pavement, a mini cinema up a back stair. Old people at the bench under a tree, kids knocking a ball about, shoppers on a mission, scratchies at the cash point” Peter Barber Our city is compact, street based and properly urban. It is small enough to be walkable; compact enough to sustain a complex economy and infrastructure. It is mostly laid out on a ladder of intimately scaled streets running down to a promenade to a central square. Streets are well integrated and foster strong visual connection between adjacent socio/economically diverse neighbourhoods and with the wider city and seafront beyond.
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Streets are interspersed with parks and sports facilities, small shops and workplaces. Schools are small, walkable, and embedded in their local neighbourhood. Somewhere the street grid might give way to a more complex picturesque, labyrinthine bit. At all times the street network is connected more like Sana’a than Chicago. The future cities need to be compact and walkable as the Urban Task Force and government advocates, then proper and meaningful discussions regarding density need to emerge within the built environment. Our offering in this discourse is to suggest that intensification is possible provided typologies emerge which ensure good urban design principles. The generic models illustrated in this report are based on good quality precedents however simply replicating these models is not enough to deliver the required intensification levels. Our project identifies a principle and develops a number of hybrid typology models which can be applied to any site.
SITRA programme by REX architecture (source: www.rex-ny.com)
The emergence of the podium and tower typology is a design response to the need to safeguard quality at the street and block level with the need for intensification. The Amsterdam typology ensures good street visual and physical connectivity with secure perimeter blocks. By adding the New York tower typology to a low perimeter
block this hybrid ensures that crowding of the street does not happen (where the perimeter block is too high for the proportions of the street. By stacking residential and other uses in a tower the site can deliver more capacity than a standard perimeter block. With the decision to transform the Ravelin Park area of Portsmouth into a large new urban area delivering 200 PPH and 500 PPH capacity it is obvious to consider how the compact sustainable and walkable city could be used to demonstrate a new model of development. Our work demonstrates how intensive a city or neighbourhood could be developed and how to safeguard quality such as public squares and parks.
“in his 1924 book ‘One Way Street’ the Marxist cultural critic and philosopher Walter Benjamin describes the culture and form of the city of Naples. In it he captures fleetingly but beautifully the idea of a city and of architecture animated and activated by the business and activity of its occupants and of space as inert without people and culture. He sketches for us the colour and frantic activity made possible by spatiality that is ‘permeable’ - which invites occupation. He gives an intimation of the fragile and complex reciprocal relationship that exists between people and spaces, between culture and architecture”
Sub-issues Our research into the compact sustainable city and associated development models has revealed a number of themes for further study and development. If higher levels of intensification are to be delivered in the built environment will require testing to establish the limits of quality. The levels of intensification seen in countries like India and China will fall short of western design standards. At some stage a tipping point will be reached when quality drops away from dense urban development. Our findings suggest that this point is achieved when population exceeds the natural levels sustainable by the size of the plot where conventional typologies are implemented. The exception to this rule is the tower typology which generally uses nearly 100% plot coverage and yet through the vertical emphasis of the typology, the drop off in quality is not as profound as with the Genoa Courtyard typology. We call this phenomena ‘herding’ and is perhaps a response to the psychological fear of crowd crush where such is the level of population intensity that there is simply no respite. If hybrid typologies are deployed, as illustrated in this report, to rapidly growing areas then more options for development are available.
Compact model What happens when density exceeds the compact city model? The new compact urban typologies developed in this project introduce non traditional urban spatial possibilities.
Traditional notions of urban design are capable of delivering low to medium density development in suburban areas. In traditional urban areas capacity is often increased at the individual block seldom the entire neighbourhood. If levels of intensification such as 200 PPH and 500 PPH are to be delivered then different urban forms are required. However these need not be totally new and some can be Peter Barber seen in historic cities in Italy, Spain and Portugal. Urban settlements such as Sienna are characterized by very dense cores and yet the The density models illustrated in this report are driven by an optipublic urban spaces are exceptional. We need not worry as we have mistic, but we think realistic, view of society and of an architecture been there before. and urban design that can help shape cities that are economically and socially sustainable.
10.0 CONCLUSIONS
Private and public space Intensification requires the rebalancing of notional boundaries between private and public. In the design of the compact urban typologies our work points to the possibilities of increased density that also introduces dramatic differences and intensive urban spaces. The cultural and societal issues generated by intensification are very profound. Our research of Sana’a identified a typology that was perfectly suited to its context and method of consumption. However if European cities are to develop higher levels of intensification then the boundaries between public and private space will need to be redefined. Perhaps the components of Sana’a are transferrable to western developed cities. Indeed the historic city of Venice offers another model for the compact sustainable city. A city free of cars has no choice but to be compact and walkable and yet the public spaces act as meeting place for groups of people and the vernacular typologies often have very little private space. The boundary between private space and public space in Venice and Sana’a is non traditional and yet both cities – for different reasons – are blessed with very high environmental quality.
Less private space At the individual scale what is the accepted level of reduced private space in order for better quality public and urban realm. The levels of intensification outlined in this report have required a redefinition of the levels of private space available to the individual. This sub theme exposes cultural differences between UK, US and Australian communities and those of continental Europe, Asia and Africa. There is an expectation in the UK that individual houses come with a high level of private space. This directly leads to urban sprawl and huge suburbs as seen in Melbourne and Los Angeles.
Reduced private space is acceptable in cities such as Genoa, Florence and Seville perhaps owing more to a communal and social demographic. An interesting side note to this is the relatively low levels of antic social behavior seen in European cities which despite high levels of intensification seem to get along in close proximity. This is a statistic not yet common in the UK or US in dense cities.
prove quality and to do this neighbourhoods need to support proper mixed use facilities which in turn places demands on non traditional building typologies to support the desired levels of intensification. It is by the careful development of building typologies capable of providing the required capacity that allow mixed use to develop and still allow the public realm to flourish.
A reduction in private space allows more flexibility for building typologies to provide increased capacity. This could mean that balconies and courtyards become acceptable private space rather than large back gardens. In order for reduced private space to be acceptable to consumers and market forces it will be important to provide improved public realm and high quality squares.
The street
Quality threshold Where is the tipping point in density levels when quality drops away and the quality of the urban and public environment becomes poor. Modern cities currently being develop in the Middle East such as Dubai and Sao Paulo in Brazil are characterized by levels of intensification so high that the public realm and general quality of the built environment is very poor. Many of the streets in Dubai do not function as traditional streets and are now reduced to transit arteries dominated by rapid transport and poor environmental conditions. Tower typologies use generally a 100% site coverage but do not suffer the same crush effects as seen in the Genoa model. This inverts the finding made between the Dresden and Genoa typologies and perhaps bucks the trend and by simply going higher and higher they safeguard quality. There is a technical constraint and also plot and construction efficiency with going super high (for example the height of The Shard in London). We suggest that the tipping point for quality is where the city becomes so large that inter district transport is required. Here lies a conundrum with infrastructure as only very large populations can support rapid and complex public transport systems such as London. Removing the need for inter district transport is one way to im-
The relationship of the ground and near ground stories to the street and public realm becomes crucial if intensification is to succeed Streets work: they are ingenious and effective means of organizing public space. They are essential to the social life of cities. The case studies described here in this report are all based on the idea of the ‘street’ as central to successful urban design; designed to bring people into close proximity, where residents are highly visible to one another and where there is a strong likelihood that they will meet. They are projects designed to promote a high level of interdependence between individuals, and in the long term it is hoped that they might help to empower groups of people who are strongly self determined. The image portrayed by Jane Jacobs in her seminal book ‘The Death and Life of Great American Cities’ where a young girl is seemingly set upon by an undesirable man in a New York street and seems doomed. However the all day activity and the concept of eyes on the street see many people come instantly to the girls rescue. This is only possible in a good street and a good place. Higher
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