Green design is an attractive alternative these days. But given the eco-friendly mission of the School of Forestry and Environmental Studies at Yale University in New Haven, Conn., building green was not an option. It was an imperative. In planning their new $33.5 million building, school administrators not only sought to create a healthy place to study and work, they also wanted to bridge the gap between nature and people, deep in the heart of the city. That goal was met with aplomb by Hopkins Architects, of London, whose Kroon Hall—designed to consume half the energy of an equivalent academic building and reduce greenhouse gas emissions by 62 percent—is targeted to achieve LEED Platinum.

A blend of optimal performance and good design, the new home to faculty offices and an environmental resource center cuts a contemporary image while fitting comfortably among the venerable landmarks of Yale. “The challenge was to convert a backyard into a nice place,” says Hopkins director Michael Taylor. A gas-fired power plant, parking lot, and assorted dumpsters were removed from the site, replaced by the new academic center and two courtyards that knit the campus together. “That’s a big win,” Taylor adds.

Working with executive architect Centerbrook Architects and Planners and sustainability consultant Atelier Ten, Hopkins created a 58,000-square-foot facility whose tall, narrow shape and east-west orientation reinforce the active and passive strategies used to heat and cool it. The lowest floor is set into a hillside, with only its south side exposed, providing thermal insulation and increasing the amount of natural light that enters the building from adjacent courtyards. A south-facing colonnade encourages activity to spill outside.

Thick walls of Briar Hill sandstone on the north and south façades have operable, high-performance windows set deep within precast concrete surrounds to shade from summer sun. Raised above the walls is a barnlike roof supported by arched frames of laminated Douglas fir. The roofline, lined in red oak (half of which comes from Yale’s own forests), creates a third-floor loft that houses an auditorium, two classrooms, a café, and a large common room.

As part of the design process, the team evaluated some 25 different sustainable measures to determine which were most cost- and energy-efficient. A 100-kilowatt photovoltaic array on the rooftop proved most desirable. It supplies 25 percent of the building’s electrical need. (The remaining electricity will be purchased from renewable sources, allowing the building to meet its goal of carbon neutrality.) In addition, four solar panels embedded in the southern façades help provide the building with hot water. Heating and cooling is provided by ground-source heat pumps that draw water from four 1,500-foot-deep wells near the building.

Integral to the building’s design is a displacement ventilation system that moves air through a plenum and into occupied spaces through diffusers in the raised floors. Low-velocity fans in the basement keep the air circulating almost imperceptibly. Fresh air is fed into the building through this system in summer and winter. But in spring and fall the mechanical systems are shut down, and occupants (prompted by color-coded lights) open the windows for ventilation.

A rainwater harvesting system channels water from the roof and grounds to a garden in the south courtyard, where aquatic plants filter out sediment and contaminants. The graywater is then used for landscape irrigation or pumped back into Kroon Hall for flushing toilets. In tandem with low-flow fixtures, the system is expected to save more than 500,000 gallons of potable city water per year.

Just four years ago, Yale President Richard Levin pledged to achieve a 43 percent reduction in Yale’s greenhouse gas emissions by 2020. With the completion of Kroon Hall, the most sustainable building on campus, the university has taken concrete steps to achieve that goal.

Sir Michael Hopkins, Chairman, Hopkins Architects
Sir Michael Hopkins, Chairman, Hopkins Architects
Michael Taylor, Director, Hopkins Architects
Michael Taylor, Director, Hopkins Architects
Mark Simon, Partner, Centerbrook Architects and Planners
Mark Simon, Partner, Centerbrook Architects and Planners

Project Kroon Hall
Location New Haven, Conn.
Client Yale University—John Bollier (associate vice president of facilities); Laura Cruickshank (university planner); Sam Carbone (director of project management and construction); Lawrence Regan (planner); David Spalding (senior mechanical engineer); Danielle Gunther-Gawlak (project manager)
Design Architect Hopkins Architects, London—Sir Michael Hopkins (chairman); Michael Taylor (director); Sophy Twohig (project director); Henry Kong, Thomas Corrie, Tom Jenkins, Nate Moore, Edmund Fowles, Andrew Stanforth, Kyle Konis, Rose Evans, Sascha Novograd, Laura Wilsden (project team)
Executive Architect Centerbrook Architects and Planners, Centerbrook, Conn.—Mark Simon (partner); James A. Coan (project manager); Theodore C. Tolis
Structural Engineers, Mechanical, Electrical, Plumbing, Fire Protection Arup
Sustainable Design Atelier Ten
Landscape Architect Olin Studio
Civil Engineering and Stormwater Management Nitsch Engineering
Geothermal Engineers Haley and Aldrich
Construction Manager Turner Construction Co.
Excavation and Sitework Ralph Camputaro & Son Excavating
Landscaping Valley Crest Landscape Development
Size 58,000 square feet
Cost $33.5 million


Structural steel with up to 95 percent recycled content
Capco Steel

Exterior Cladding

Sandstone masonry
The Briar Hill Stone Co.

Precast concrete
Rex Precast Systems

Structural red oak glulam beams
Goodlam, a division of Goodfellow

Douglas fir arch and louvers
Goodlam, a division of Goodfellow

Windows and Glazing

Custom metal and glass curtain wall
Kawneer North America

Custom windows
Marvin Windows and Doors

Custom skylight system
Wasco Skylight Products


Custom doors
Builders’ Hardware


Sloped metal roofing
Follansbee Roofing

Interior finishes

Cabinetwork and custom woodwork
Legere Woodworking

100 percent FSC-certified wall paneling
Legere Woodworking

Custom partitions
Partitions Inc.

ElectroShade system for motorized shades
MechoShade Systems


Custom ceiling panels
Rulon Co.


Menagerie modular carpet tiles


Think task chair

Leap task chair

B2 lounge chairs
Bernhardt Design

B1 sofa
Bernhardt Design

Luca chairs
Kusch + Co.

Custom tables
Fairhaven Furniture

Monumental entrance benches
Fairhaven Furniture


P5 wall-mount wall washing fixture
Winona Lighting

FCSLR 803 exterior die-cast recessed step light
FC Lighting

GR4B-132T8 interior downlight
Gammalux Systems

FRR-07030 fixture
The Kirlin Co.

FRR-07031 fixture
The Kirlin Co.

One Line task lighting

Design DSK-40 exterior fixture
Quality Lighting, a Philips Group brand

Lumark small Vaportight exterior accent fixture
Cooper Lighting

FCSL 505 exterior die-cast step light
FC Lighting

nLight control system
Sensor Switch


Model 225 solar photovoltaic panel


LaZer2, bespoke solar thermal domestic hot water array
Solar UK

Bespoke reclaimed water tank
Fiber Technology Corp.

Solar-powered faucets, fixtures, toilet flush valves
Sloan Valve Co.

Waterless no-flush urinals
Waterless Co.

Building Management System

Customized building management software system
Automated Logic Corp.

Special Equipment

Adsolair 561901 air-handling unit with double-pass heat recovery and indirect evaporative cooling

WW 420, water-to-water reverse cycle heat pump
FHP Manufacturing