Concept to Construction

LEERS WEINZAPFEL ASSOCIATES

CONCEPT TO CONSTRUCTION INTEGRATED DESIGN PROCESS BEHIND THE JOHN W. OLVER DESIGN BUILDING About the Exhibit The exhibit covers topics of Architecture, Landscape Architecture, Mass Timber Structure and Construction. A special focus is the story behind the Roof Garden and the Commons - integrating Architecture, Landscape Architecture and Mass Timber Structure from early design concepts thru construction.

Project Information The John W. Olver Design Building brings together departments and programs at UMass Amherst in Architecture, Building and Construction Technology and Landscape Architecture & Regional Planning into a new collaborative facility intended to foster synergy and collaboration across these disciplines.

The project occupies a pivotal site on the flagship campus in rural western Massachusetts. Incorporating a mass timber structural system, the architecture and landscape takes inspiration from regional agrarian patterns that hark back to the school’s roots as a land-grant college where local pastures and fields served as laboratories and working classrooms.

The building functions as a dynamic space of exchange, collaboration, and experiment that demonstrates a shared commitment to sustainability. As the largest cross-laminated timber (CLT) academic building in the US, the key feature of the interior is the innovative and expressive use of engineered timber. Exposed timber columns, timber floor slabs and glue laminated cross-bracing are expressive of the building’s materiality. Natural finishes are celebrated.

To create a central space of collaboration, an ascending band of maker-spaces, studios, faculty offices and classrooms coils around a sky-lit Commons intended for gathering and presentations. The Commons features a stepped-seating area and a monumental cross-laminated timber stair that ascends 2-stories. Furnishings are flexible, mobile and adaptable to various academic activities and events. Functioning as the building’s physical and spiritual heart, the Commons acts as a three-sided courtyard that spills out through the café and entryway, down into the main campus, and invites the campus in.

Another key feature of the design is the roof garden with its wood pavers, benches, and plantings. This open-air virtual “classroom” intended to evoke an alpine summit garden, incorporates wild-harvested sods, bare root plants and young evergreens.

Within the studios, labs and teaching spaces, mechanical systems are revealed, most are painted but left exposed. The buildings systems are intended as demonstration and teaching tool in a space designed to house architects, engineers, landscape architects and planners.

The Olver Design Building celebrates the beauty of timber as structural system, architectural feature and interior finish. Together with natural daylight, the exposed wood structure gives a sense of warmth and comfort to these spaces. The glass and copper-color anodized aluminum building envelope features large areas of curtainwall and a syncopated pattern of punched windows. The large glazed-expanses are designed to connect interior spaces to the larger campus and highlight the relationship of interior to the landscape.

The building would not be constructed with timber were it not for the political will of Former Congressman John W. Olver. After discussions with Building and Construction Technology (BCT) faculty about the role a timber demonstration structure could have in supporting local forest economies, a contingency fund was put in place by the legislature. This additional funding guarantee ultimately enabled the university to embrace the new technology.

Project Team Architect: Leers Weinzapfel Associates Landscape Architect: Stimson Structural Design Engineer: Equilibrium Consulting, Inc. Structural Engineer of Record: Simpson Gumpertz & Heger MEP/FP Engineer: BVH Integrated Services Lighting and Sustainability: Atelier Ten Civil Engineer: Nitsch Engineering Code: Howe Engineering Construction Manager: Suffolk Construction Mass Timber Fabrication: Nordic Structures Mass Timber Installation: Bensonwood, North & South Construction Client: University of Massachusetts Amherst & University of Massachusetts Building Authority Owner’s Project Manager: Hill International Exhibit Team: Leers Weinzapfel Associates, Stimson, UMass Amherst BCT Exhibit Sponsors: Woodworks, UMass Amherst departments of Architecture, LARP, and BCT Photo Credit: Albert Vecerka / Esto, Alex Schreyer / BCT, Langer Hsu / LWA, and Ngoc Doan / Stimson

Architecture

Building and Construction Technology

Landscape Architecture and Regional Planning

ARCHITECTURE CONCEPT

Site Selection + Campus Circulation At a campus scale, the Design Building also serves as a connector and mediator for two campus sides: formal large-scale Haigis Mall to the west and small-scale historic campus to the east. The building form responds to the contexts by keeping a more intimate scale, reflecting the surroundings along Stockbridge Road while rising along North Pleasant Street to meet the Fine Arts Center. The design presents a campus pathway with entries from both ends.

Conceptual Studies Even from the start, the building was conceived to engage the landscape and the slope of the site, with a strong connection to the campus pathways. It’s interior was imagined with a flexible, central social hub with teaching and learning activities on display.

Courtyard Form A Courtyard building form was selected given the need for a common, central space to bring together the three departments.

The courtyard was then opened up in plan and lifted up in section to connect the building’s interior to the campus and to address the scale of the Fine Arts Center and Haigis Mall.

Vernacular Inspiration The building is clad in recycled copper anodized aluminum panels. The vertical syncopated pattern of windows is meant to evoke the imagery of regional forests and hark back to the 19th century tobacco barn an agrarian building type once common to the area. The copper color of the building’s skin echoes the darker protective bark of trees while the lighter colored wood throughout the interior, echo its lighter inner layers.

FINE ARTS CENTER

ARCHITECTURE PROCESS

Building Envelope + Wall Section Carefully placed expanses of glazing and skylights provide maximum daylight to the building’s interior to significantly reduce artificial lighting energy. These large glazed areas are designed to connect interior spaces to the larger campus and highlight the relationship of interior to the landscape. A consistent module of two window sizes (wide and narrow) reinforced the concept of a singular building envelope across all the building facades while accommodating the building’s range of spaces from large studios to small offices.

The building’s sustainable rain screen envelope assembly was carefully distinguished from the building’s timber structure given the code requirements of the building’s Type 4 construction type.

Interior Finishes Few additional finishes were required except in select areas as required for mechanical or acoustical performance. The limited use of finishes is not only economical but also sustainable. Use of adhesives often associated with finish systems was avoided.

Building Section When was the last time you entered a newly constructed academic building and deliberately inhaled it?

— Laura Miller , UMass Magazine

A key mission, developed together with the client and faculty, is to expressively demonstrate the integration of building, landscape architecture, and building technology. It occupies a pivotal site on the Amherst campus and brings together the community into “the Commons” where students and faculty gather for organized and informal activity. The welllit space offers visual connection to studios and maker spaces, embracing the university’s collaborative goals.

LANDSCAPE CONCEPT

Pelham Hills Berkshires

The Valley

Connecticut River Valley

The University of Massachusetts flagship campus is located in Amherst, MA. A dramatic landscape of agricultural fields, woodlands, outcrops and ravines, the campus is at the convergence of the Connecticut River, Berkshire Mountains and the Pelham Hills. Founded in 1892 as an agricultural school, UMass has some of the earliest academic ties to the agrarian landscape and horticultural education in the country.

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FOUNDED IN 1903 AS ONE OF THE OLDEST LANDSCAPE ARCHITECTURE PROGRAMS IN THE COUNTRY, SECOND ONLY TO HARVARD UNIVERSITY, FRANK A. WAUGH, THE FIRST DEPARTMENT CHAIR, PERFORMED YEARS OF HORTICULTURAL EXPERIMENTS IN TEST PLOTS ON THE ACTUAL SITE OF THE NEW DESIGN BUILDING.

Studio Arts

History and Scope

Stormwater Garden

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Campus Pond

Spring Source Garden

Stockbridge Way

The design created two major pedestrian thoroughfares, fulfilling a long-time Master Plan goal for safe pedestrian movement.

The restoration of the historic Stockbridge Way as a pedestrian-only corridor, and a new connection to the Fine Arts Center along the North Slope Ravine.

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In recent decades, the site was an expansive parking lot and contributed seasonally to the sedimentation of the campus pond. It became paramount to the design process to restore a visibly functioning ecosystem with the notion that every aspect of the project should be a teaching opportunity.

The landscape is used as a classroom for detailing, site engineering, plant ecology, soil science, and stormwater management, reinforcing the expression of horticultural experimentation that is rooted in the history of the school.

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A grove of Sassafrass albidum and Fagus grandifolia define the east entry garden, reminiscent of the wooded slopes that rise above this part of campus. Salvaged bluestone slabs and site walls retain the grade, creating accessible and occupiable entry gardens. Water flows from the building scupper into a pre-treatment spring source garden before streaming down the north slope ravine. Check dams of Robinia pseudoacacia and diversely planted forebays create a visible system of water management.

At the outdoor workyard, a stand of Carya ovata gives shade to the student and faculty projects. Eventually, site runoff makes its way to the western stormwater gardens.

These gardens mimic the planting of the Connecticut River’s intervale meadows, with grasses and perennials giving a wilder expression to the western façade of the highly public North Pleasant Street entry.

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Transformation

LIVING LAB

THE LANDSCAPE IS A COLLECTION OF GARDENS REPRESENTED BY FAMILIAR ECOSYSTEMS FROM THIS PART OF WESTERN MASSACHUSETTS, EACH ONE WITH A PARTICULAR FUNCTION RELATING TO THE SITE’S HYDROLOGY AND TOPOGRAPHY. TOGETHER, THEY FORM AN OUTDOOR CLASSROOM, A LABORATORY FOR LEARNING AND A RESTORED COLLECTION OF PLANT COMMUNITIES.

PLANT LIST TREES Abies balsamea Balsam Fir Picea mariana Black Spruce Tsuga canadensis Canadian Hemlock Amelanchier canadensis Shadblow Serviceberry Acer rubrum (native) Red Maple Acer saccharum Sugar Maple Betula alleghaniensis Yellow Birch Betula papyrifera Paper Birch Carya ovata Shagbark Hickory Fagus grandifolia American Beech Larix laricina American larch Nyssa sylvatica Tupelo Quercus bicolor Swamp White Oak Quercus rubra Red Oak Sassafras albidum Sassafras

UNDERSTORY + SHRUBS Hamamelis virginiana Witchhazel Cornus sericea ‘Arctic Fire’ Red Twig Dogwood Juniperus horizontalis ‘Wiltonii’ Blue Rug Juniper Kalmia angustifolia Sheep Laurel Ilex glabra ‘Shamrock’ Inkberry ‘Shamrock’ Myrica pensylvanica Northern bayberry Rhus typhina Staghorn Sumac Salix ‘Flame’ Flame Willow Rhus aromatica ‘Gro-Low’ Fragrant Sumac ‘Gro-Low’ Taxus × media ‘Everlow’ Everlow Yew

GRASSES, FERNS, PERENNIALS, BULBS Allium sphaerocephalon Allium Drumstick Arctostaphylos uva-ursi Bearberry Asclepias tuberosa Butterfly Weed Calamagrostis canadensis Blue Joint Grass Cornus canadensis Bunchberry Caltha palustris Yellow Marsh Marigold Comptonia peregrina Sweet Fern Dennstaedtia punctilobula Hayscented Fern Eleocharis palustris Common Spike-Rush Eragrostis spectabilis Purple Love Grass Gaylussacia baccata Black Huckleberry Iris versicolor Blue Flag Iris Juncus effusus Soft rush Molinia caerulea ‘Dauerstrahl’ Moore grass Matteuccia struthiopteris Ostrich Fern Osmunda cinnamomea Cinnamon Fern Osmunda regalis Royal Fern Polystichum acrostichoides Christmas Fern Schizachyrium scoparium The Blues Little Bluestem Symphyotrichum novae-angliae New England Aster Symplocarpus foetidus Skunk Cabbage Sporobolus heterolepis ‘Tara’ Prairie Dropseed Sorghastrum nutans ‘Sioux Blue’ Indiangrass Schizachyrium scoparium Little Bluestem Thalictrum rochebrunianum ‘Lavender Mist’ Meadow Rue Vaccinium angustifolium Lowbush Blueberry Vaccinium vitis-idaea Lingonberry Xanthorhiza simplicissima Yellow Root

The project has set a new ecological and creative standard for campus design at UMass and remains a landmark for our practice. Several of us graduated from the LARP program, and our experiences as students distinctly influenced our design.

We remember field labs that focused on the interconnectedness between history, culture, and ecology. Site visits around the Valley encouraged a respect for familiar landscapes and an awareness of how their associated ecologies give form and meaning to design. This interpretation of regionalism, in particular, materials and plants, became the vocabulary of the design and inspired the creation of a landscape that truly reflects the character and identity of UMass.

Alpine Summit Garden On the third floor is a rooftop courtyard, roughly 30’x70’. Surrounded by studios and faculty offices, it was conceived of as a alpine summit garden of native plants that are wind tolerant and capable of growing in very shallow soils. Inspired by the hilltops of the Holyoke Range, this courtyard offers an experimental approach to green roof design and collected species planting.

STRUCTURE CONCEPT Comparing Steel and Mass Timber One goal of this building was to demonstrate the many possibilities of designing with wood. In using wood as the dominant structural material, the superstructure frame is made of glulam beams and columns and Cross Laminated Timber (CLT) floor and roof panels. All of the structural cores for elevators, mechanical chases, and egress stairs are made of CLT panels, and in conjunction with glulam bracing, provide lateral support.

Houses are built with wood, but larger structures require greater knowledge about mass timber. Mass timber construction utilizes large sections of wood.

These sections are made from individual sticks of lumber that are stacked and glued together. That’s the composite aspect. That way you limit the effect of a defect. A knot or other feature is only an inch or two deep, and that’s as far as it goes.

Engineers don’t like variability in their material; they like predictability, and that’s what comes with the composites. It’s a system and becomes much more reliable. We have been building airplanes on this concept—aerospace engineers orient fibers and get sophisticated with their designs. We are at the beginning stages of that: taking those mathematical models and applying them to wood composites.

Steel vs Timber Design Documents While an early schematic study of a mass timber structure was done, due to many factors working against a new building construction type, the design proceeded thru the Design Development Phase as a steel building. Only after the directive to build in mass timber was given by the University, the structural system of the building was changed.

The earlier schematic study that anticipated a possible structural change and set in place fundamental structural elements such as column grids and beam spans allowed the team to more easily translate the design into a mass timber structure.

— Peggi Clouston, Professor of Wood Mechanics and Timber Engineering, BCT

Early Schematic Mass Timber Structural Plan

Design Development Steel Frame Structural Plan

A Composite Structure The structure is a composite construction of concrete, steel and timber. Each material has its inherent strengths and weaknesses and therefore its appropriate use. Concrete is used mostly at grade conditions like foundations given its ability to handle moisture and weight. Steel is used at cantilevers, transfer beams and at the large truss which takes on half of the building’s central roof load given its greater strength than wood. Wood given its smaller carbon footprint and greater strength to weight ratio as compared to steel and concrete is used throughout for the vast majority of the building’s superstructure.

Design Development Mass Timber Structural Plan

STRUCTURE PROCESS

The Timber Stair Health and wellness are encouraged starting at the ceremonial timber in the open Commons area. The goal was to design a light, inviting stair that would also showcase the mass timber technology and allow for maximum daylight to descend to the ground level.

The main stair is made of CLT panels and glulam tread blocks, suspended from the main steel roof truss with steel tension rods located every four feet. It also serves as an occasion to display the section of the CLT panels, showing its alternating laminations. With ample sunlight, the stair is open, carefully detailed and invites walking. With its generously dimensioned glulam timber treads inset with porcelain tile walking surface, students and faculty are encouraged to ascend all the way to the third floor.

Cross Laminated Timber + Concrete Composite Slab The building’s unique composite floor slab is a microcosm of the building’s integrated structural system using all three materials of concrete, steel and wood efficiently. The perforated metal connector which is glued into the CLT panels acts as the mechanical connector for the wood and concrete (a kind of “Nelson Stud” connector for the wood, which is visible in the photo welded to the top of the steel beam) . Together they work as a singular structural system with the concrete in compression and wood in tension instead of the wood taking on all the deadload of the concrete. This was necessary to allow for larger spans in the building given the large open studio spaces throughout. The composite wood-concrete floor technology was tested and researched by the BCT program at UMass Amherst.

CONSTRUCTION CONCEPT Site Layout

Project Delivery

The site of the Olver Design Building presented several challenging constraints for the duration of construction, previously home to several sought-after parking spots. A tight site layout allowed for sufficient construction equipment movement while still retaining 70 parking spots on Lot 62 during construction as well as afterwards. Construction site vehicular access was provided through two gates at the East and North edges of the site.

Personnel access was in addition provided through the construction trailer at the South edge of the site. This arrangement allowed for enough space for material handling, laydown and truck cleaning as well as some parking on-site.

Projects constructed by public agencies are highly regulated compared with private projects. In Massachusetts, the construction laws for buildings are found in Title XXI, Chapters 149 and 149A. These two chapters establish the regulations for standard Design-Bid-Build (DBB) and Construction Management at Risk (CMR) procurement methods.

Equipment Construction of the Olver Design Building employed a variety of large and small construction equipment, including cranes, lifts, concrete pumps, power trowels, and many others.

All structural elements and some of the larger HVAC pieces (e.g. vertical ducts) were handled by roving Rough Terrain telescoping cranes. Most of those were able to move a 60 Ton load, which was sufficient for the wood structure (including stair shafts) and all steel beams (except the large truss, which required a 150 Ton crane).

On-site material handling of smaller pieces was done with a Forklift Telehandler. The most versatile piece of equipment, however, was the Boom Lift (colloquially called a “Cherry picker”). Those were used to guide structural placement, attach fasteners, install the roof truss elements, and install façade panels.

Massachusetts construction laws, both Ch. 149 and 149A, are filled with unique features that are designed to prevent bid manipulation and fraud, which until the 1980’s was a big issue in the state. Massachusetts is unusual in that it requires public agencies that wish to construct or renovate buildings to use licensed design professionals to provide oversight, bid specific trades separately from the general contract (called File Sub-Bids), and a host of other requirements. Chapter 149 was first created to ensure that public agencies obtain competitive bids for work of any substantial size (over a few thousand dollars), exclusively using a design-bid-build process that would ensure both design appropriateness as well as competitive and fair bidding.

After many years of trying to construct all projects in this vein, which often required years of design, then bidding, and failing to find a contractor that could meet the budget requirements of the contracting agency, the state developed a Construction Manager at Risk method that preserves most of the requirements of Chapter 149 but allowing agencies to select a Construction Manager who, for a fee, would help to marry the agency’s programmatic requirements with their budget, manage the File Sub-Bid process, and contract with the Agency that the project will be built for a Guaranteed Maximum Price (GMP) before all the usual bidding documents are completed. Not incidentally, the CM has more latitude in bidding non-filed trades (which includes the structural components) than Chapter 149. This process, called Chapter 149A, is designed to save time, and thus money, and offer flexibility for the Agency.

The John W. Olver Design Building was constructed using Chapter 149A methods. This approach was selected by the University and the University of Massachusetts Building Authority (which issued the financing bonds to construct the project) after the initial programming for the building revealed a strong desire of the University to construct the project with Mass Timber framing. Because Mass Timber was at that time untried in a public building in Massachusetts, it was determined that the project would greatly benefit from having the bidding entity (the Construction Manager or Contractor) estimate costs and prequalify and preselect bidders for the framing systems. That process, during which over 12 construction management firms were evaluated, resulted in the project being constructed by Suffolk Construction, and the timber framing systems were supplied by Nordic Structures, selected from an interested pool of about six potential suppliers.

CONSTRUCTION PROCESS

Fabrication Modeling Based on the designers’ Revit model, a digital structural model was developed in cadwork, a specialized wood design and fabrication software. This model contained every glulam beam, cross-laminated timber panel, and fastener, and allowed for direct export to CNC (computer-numerically controlled) fabrication machines.

CNC Fabrication Nordic, the Canadian supplier of the entire superstructure (wood and steel elements), used a CNC-based fabrication process to trim CLT panels, cut openings, shape glulams, and cut slots and holes for fasteners. This allowed for highly precise wood structural elements to be delivered to the site, which then simply needed to be bolted in place. In addition, shaft wall and floor panels were typically connected onsite with full-thread structural screws (up to 2 feet long in some cases).

Foundation connections for columns used pre-made steel double-baseplate pieces that were bolted to threaded anchor rods. Vertical CLT shaft walls had to transfer higher structural loads into the foundation and therefore used long steel hold-downs (themselves glued into the edges of the panels) together with Dywidag rods, set into the foundations.

Working Conditions Having precise, pre-fabricated structural components meant that no on-site cutting and adjusting was required, which in turn reduced construction noise. Also, heavy-timber elements have an inherent fire-safety due to their massiveness, which means that it is possible to leave surfaces uncovered. As a result, columns, walls, and floor undersides were completely finished as soon as they were placed. This “structure = finish� concept also contributes to a more pleasant working environment on-site.

INTEGRATION CONCEPT

Concept Sketches The roof garden was envisioned as balance of hardscape and softscape, a place of outdoor gathering and a demonstration garden for greenroof experimentation. With these main parameters, various configurations across architecture, landscape architecture and structure were explored in early stages.

Early section sketch thru the Commons and Roof Garden shows areas of deep soils necessary for trees and plantings to create a garden feel, without yet a sense of the timber structure. The main ceremonial stair connecting all levels is already in place.

Process Models

Structural Concepts Sketches

Early models of the Commons and the Roof Garden show a wood spanning structure with multiple skylights and interest in addressing the building’s geometry and structural grid.

Many ideas about the nature of the structural system to span the roof were explored, from simple and repetitive glulam space frames to geometrically complex CLT slab bands.

INTEGRATION CONCEPT

Maintaining a Garden The design team was tasked with re-designing the Roof Garden structure from steel to wood at the end of the Design Development phase. This dramatically changed the design for the rooftop courtyard which had been previously supported by deep steel trusses with a soil depth of 2 feet. As LWA and Equilibrium collaborated on an innovative “zipper truss” structure to span the roof garden, Stimson had to re-create a garden on less than 6” of soil in most places. These parameters were too restrictive to support the trees and shrubs in the initial roof garden plan.

Continued design meetings considered roof loads, zipper truss dimensions and desired plantings which determined the strategic placement of deeper soil areas. The short span of the roof and the main steel truss support the mounded soil and planters that allow for greater soil depth for trees and shrubs. Though much of the garden is built on shallow soils, the variation of soil depth mimics the condition of an alpine summit, provides a diverse plant palette, and creates a unique rooftop garden for students and visitors.

Final Roof Truss concept

Parametric Modeling

The roof structure was refined to what became known as the “Zipper Truss” since all the elements of the truss are brought together along the middle of the structural span.

Hand sketches and physical models were used to arrive at the overall geometry of the Zipper Truss.

Then parametric modeling software-Grasshopper was used to set parameters to all components of the truss such that its refinement could be done efficiently given that many rounds of adjusting working points, member sizes and connection details remained.

In concept, the structure is quite simple: each span is divided into equal thirds and at these third points, the loads are transferred to diagonal wood compression members which meet at the middle. The forces in compression are then transferred by steel tension rods to the end points of the truss beam where they are supported by columns along the south side and by a large steel truss along the north.

INTEGRATION PROCESS

Skylights and Seating Skylight configurations and built-in seating arrangements went through many iterations, first as asymmetrical roof shapes inspired by rocky contours of alpine summits, to ultimately becoming pyramids that would echo the shape of the zipper truss below.

The truss system holds up our green roof, so that fulfills the structural needs and the roof garden fulfills landscape architectures needs. The question is, how, with a wood structure, do you support a heavy load like a green roof?

To avoid deflection, or bending of the floor, the heavier planting beds are off to the sides and the gathering space is in the middle. The low profile and type of soils require that it’s irrigated. The design concept is an alpine theme stunted plants and low trees, blueberry bushes - it’s going to look like the top of a mountain.

Span – Load Coordination Given the Right Trapezoid geometry and the column free clear span below, heaviest loads on the roof garden had to be assigned to the perimeter and the short end.

The longest span across the garden was conversely the thinnest soil profile. This portion of the garden is planted in bands with varying depths (3”-7”) in response to the wooden truss below. These areas incorporate plant micro-colonies and locally harvest wild sods.

—Michael Davidsohn, Senior Lecturer, Landscape Architecture

Connection Studies Mass Timber design is often as much about its connections as it is about the material itself. Connections can present opportunities for architectural and structural expression.

The challenge with the zipper truss was to create an elegant solution that was at the same time, structurally honest and efficient. Back and forth architectural and structural sketches along with digital modeling shown here convey the intense collaboration that made the refinement of the connections possible.

INTEGRATION PROCESS

Large Scale Models This is a great people-watching space and a vantage point where you can see all of the various activities. You can get the excitement of this building.

Connection Types The evolution of the central connector of the zipper truss began as a simple plate connector, then became a sphere shape due to the mass required to accommodate heavy roof loads and finally evolved into a combination of a solid cylinder that had the necessary mass with eight rounded triangular plates to accommodate the truss members.

—Stephen Schreiber, Professor and Chair, Architecture

In addition to sketches and digital models, large physical models at ¼” scale were made to study the scale of the Commons and the Roof Gardens.

This gave confirmation of the overall balance of the roof garden configuration between the wood deck gathering areas and the planted landscape areas.

The large-scale model also confirmed the overall feel of the zipper truss, its depth and height relative to the space below it.

INTEGRATION DOCUMENTATION

Skylight Section Building a robust and water-tight roof structure was of primary concern. The same composite CLT-concrete system that was used on the typical building floor plates were used here. The concrete on top of the wood structure extended to form all curb cuts on the roof garden to ensure a robust surface and substrate for the waterproofing system with rigid roof insulation boards above it. All roof assembly components such as planting system and the wood deck system then rest on this waterproofed roof assembly. The roof structure was cambered to create low points along the north and south perimeter where six roof drains collect the rain water and melting snow and connect them to the storm drain system.

Architectural, Structural and Landscape Documentation Complex geometry of the roof truss was digitally modeled in Rhinoceros 3D software and then translated into the overall BIM Model “Revit� for production of details and documentation. Shown here are the architectural roof garden plan and the reflected ceiling plan of the truss structure below as well as their comparative structural plan and the landscape planting plan.

INTEGRATION DOCUMENTATION

Roof Garden Planting Plan

ALPINE SUMMIT GARDEN PLANT LIST Arctostaphylos uva-ursi Kinnikinnick Betula papyrifera Paper Birch Cladonia cristatella Red Soldier Lichen Cladonia rangiferina Reindeer Lichen Clematis paniculata Sweet Autumn Clematis Cornus canadensis Bunchberry Dogwood Dennstaedtia punctilobula Hayscented Fern Dicranum scoparium Broom Moss Empetrum nigrum

Black Crowberry Gaultheria procumbens Wintergreen Humulus lupulus ‘Aureus’ Golden Hops Juniperus horizontalis Blue Rug Juniper Kalmia angustifolia Lamb’s Kill Lenucobryum glaucum White Pincushion Moss Lycopodium obscurum Rare Clubmoss Lycopodium tristachyum Blue Clubmoss Mitchella repens Partridgeberry Myrica pensylvanica Northern Bayberry Paxistima canbyi Rat Stripper Picea mariana Black Spruce Polypodium virginianum Rock Polypody Polytrichum commune Hair Cap Moss Quercus ilicifolia Scrub Oak Tortula ruralis Star Moss Tsuga canadensis Canadian Hemlock

The entire roof garden sits on this open and beautiful zipper-truss structure: this big glue-laminated beam and the diagonals that are tension rods. The round, wooden diagonals are in compression and the metal is in tension. So the steel is being pulled apart and the wood is being squooshed. They’re basically like branches holding the roof up, tied back to the end corners.

—Alex Schreyer, Senior Lecturer and Program Director, Building and Construction Technology

Detail Documentation Complete details and documentation for every connection of the roof structure ensured the design team ownership of these details in a publicly bid- construction process. It also allowed for easy transfer of information from the design team to the construction team and ultimately to the Mass Timber structure fabricator. These fully developed details to produce their fabrication models that would feed the necessary information to the CNC machines that would cut and shape the wood members to receive the various connectors.

The challenge presented by limited soil depths led to an inspiration in the summit landscape and a plant palette that thrives in those difficult conditions. We researched alpine plants, soils and microclimate, and came up with a plant list that relied heavily on bare root and collected species.

Wild sods like Cornus canadensis, Gaultheria procumbens, and Mitchella repens were transplanted from nearby sites to the shallow soil, while young evergreens such as Picea mariana and Abies balsamea were placed in the deeper pockets of soil waiting to become windswept and stunted like their counterparts on the summit of Mt. Holyoke.

INTEGRATION CONSTRUCTION

Landscape Installation

Living Laboratory

The largest span across the garden was conversely the thinnest soil profile (3”-6”) in response to the wooden truss below. In these areas, we worked alongside the contractor to carefully plant micro-colonies of species of lichen and moss.

As a place for learning about regional plants, the Design Building’s landscape is a test plot that will be monitored by the students and faculty of Landscape Architecture and Regional Planning Department.

Fabrication The truss structure is a highly efficient yet varied combination of different fabrication methods. The compression diagonals were made of lathed glulam members whose ends feature cast steel connectors that were fastened using glued-in threaded rods. Those diagonals then connect to the “bullet” points that are a combination of a cast steel core and welded plates.

This bullet then transfers forces in tension back to the edges of the zipper truss using pre-made (catalog item) BESISTA solid-steel rods and eyebolt connectors.

All truss members were installed in place by first hanging, and then rotating and assembling the members with steel pins. Therefore, precision pre-manufacture was key for the success of this detail.

INTEGRATION CONSTRUCTION

Alpine Summit The rooftop courtyard offers a tangible approach to rooftop planting in our New England climate that strays from the predictable sedum garden and instead, is inspired by place-making and the hilltop ecologies of western Massachusetts.

When a client, in this case, the university, gives an architect a brief, it includes a list of requirements. We didn’t say explicitly, “Give a big common space.” On the client side, you have to voice your highest aspirations for a project. So we were saying, “We need a space for gathering and for collaboration,” and they were saying, “How can we design a building that gets you that?”

For architects, their true skill set is to pull every square inch and throw it at the question. That’s what I try to teach my students—spatial intelligence.

Our architects collected every extra square foot that they could to create common spaces that met our highest aspirations. Every time I walk by here, that’s what I think about. Now those spaces are filled all day, every day.

When I walked in the building the first day and saw students sitting on this ledge here talking, I practically cried.

— Caryn Brause, Assistant Professor, Architecture

Technology on Display Exposed wood structure combined with daylight create spaces that are bright and warm, and sensitive to touch and smell of wood; spaces that foster human comfort, productivity, and well-being. The central commons of the building displays both the strength and expressive potential of wood, with a “zipper truss” that supports an intensive roof garden above; CLT roof panels are supported on three-dimensional array of triangulated glulam and steel rod trusses.