Finally Living After All These Years

In mid-March, the Class of 1966 Environmental Center achieved Living Building certification from the International Living Future Institute (ILFI), becoming just the 34th building in the world to achieve full living certification. 

photo of people on the terraced grass steps eating a picnic
The terraced steps in front of the Envi Center

Completed in 2015, the building earned ILFI’s Petal (or partial) certification after meeting requirements for six of the seven petals but fell short on the energy petal. After making modifications to both the energy and water systems, which included installing additional solar photovoltaic (PV) arrays and reworking the water filtration system, the building started a second 12-month performance period.  The Williams team, with the help of local sustainability consultant Integrated EcoStrategy, then resubmitted documentation for a second audit and the Envi Center was finally awarded full Living certification. 

Sheep inside a fence and students outside of the fence in front of pole mounted solar arrays.
Sheep from the Spring 2023 Parilia event in front of the additional pole mounted solar arrays.

ILFI’s Living Building Challenge (LBC) is among the most ambitious sustainable building certifications since it requires both the energy and water systems to perform at net zero (produce as much energy as the building consumes and harvest as much rain water as the building uses on site) over the course of a continuous 12-month performance period.

For the Envi Center, the actual energy production from the solar PV arrays on the roof, ground, trellis, and the trackers to the east of the building was less than the energy modeling had predicted.  Because of that shortfall, additional arrays of pole mounted solar PV were installed between the building and the Hollander Hall parking lot.  In addition, the water system, which had passed the initial performance period test, experienced several challenges in its energy use and operational filtration needs and was redesigned and rebuilt by Williams College Sustainability Project Manager Doug Schlaefer and Berkshire Engineering.  

Four students doing meal prep around a counter space.
Student interns cooking in the Envi Center’s kitchen.

Achieving ILFI’s Living certification is particularly noteworthy because the Envi Center is a hybrid of new construction and a renovated historic building. When looking at the building, the left side was formerly Kellogg House, built in 1797, home of the first four college presidents and has been located on Route 2 where Hopkins Hall now sits and again to what is now the parking lot for Sawyer Library.  The building houses multiple departments, the Center for Environmental Studies and the Zilkha Center, and the spaces include:


  • a classroom, 
  • a living room, 
  • a kitchen in the basement with energy efficient equipment, 
  • two composting toilets, and 
  • a number of study spaces including a number of “stump tables” on the main floor made from trees that were felled during construction and then turned into tables by a local artisan on Florida Mountain.   
Ducks on the bank of a small pond with a light snow on the ground.
Ducks coming out of one of the ponds on the north side of the Envi Center.

In addition to the solar PV that one can see surrounding the building, the building site includes gardens, orchards, and small ponds that help to provide habitat for turtles, frogs, and sometimes ducks, and has lots of outdoor seating encouraging people to use both the inside and outside spaces.

Countless classes and student groups have toured the building since its completion. It has also been a destination for many field trips for local school groups as well as inspiration for others in the region and across the country who are considering pursuing the Living Building Challenge.  Visitors have included leadership from the Cope Environmental Center who were considering an LBC project, 80 design and construction professionals as part of a NESEA (Northeast Sustainable Energy Association) Pro Tour, and a class from Middlebury’s Architecture and Environment course studying LBC and making recommendations about a sustainable building certification for a building project on their campus.  Many guests have been immortalized on the Wall of Fame inside the doors leading to the composting toilet collector.  

One contractor showing three students some of the finer points of the composting toilet bin in the basement.
Education happening in the composting toilet bin.

Over the years, classes including Joel Lee’s Waste Values course have studied the building and individual students have based projects on the building and site. These include Jaya Alagar’s ‘22 and Petra Baldwins’ ‘21 research on pharmaceuticals in composted solid waste after land application and Caroline Atwood’s ‘16 thesis on water balance and hydrologic performance on the Envi Center site.  (Instagram link for more)

Energy and water are just two of the seven petals.  The others are Place, Health & Happiness, Materials, Equity, and Beauty.  They give you a sense of how LBC thinks about sustainability in terms of the land on which buildings are situated (Place Petal) but also the building’s occupants and people involved with the creation of the building (Health & Happiness and Materials). 

This building and building project process has informed the college’s updated Sustainable Building Policy and inspired other campus capital building projects. Williams’ other ILFI building projects are CDE Fellows Hall (ILFI Net Zero Energy, completed in 2019), Fort Bradshaw (LBC Petal & LEED Gold, completed in 2021), the Davis Center building project (pursuing LBC Petal certification, completed in 2024), and the new WCMA building (pursuing LBC v4.0 Core certification, in the design phase). 

We hope the Envi Center and other highly sustainable buildings will continue to serve both educational and functional purposes and inspire the college and others towards increasingly ambitious sustainable buildings.

A class sitting on the grass behind one of the two solar trackers, half the students sitting in the shade and half sitting in the sun.
Enjoying the shade of the solar trackers on the east side of the building.

For more information on the building, please visit the Environmental Center’s website.

-Mike Evans, Deputy Director, Zilkha Center for Environmental Initiatives