Passive House Grows on Campus

Wheaton College in Massachusetts has opened the largest Passive House residence Hall in New England.

• By Kate Starr, Richard Lucht
• 09/01/19

PHOTO COURTESY OF COMMODORE BUILDERS

For years colleges and universities have been looking to find new and innovative ways to attract students. What students find most appealing is not necessarily the same now as in the past and may not be the same in the future, but one thing is clear today: students want their campuses to be environmentally friendly and utilize sustainable practices on a daily basis.

That’s why colleges like Wheaton College in Norton, MA, are focused on carefully and significantly reducing their carbon footprint in constructing and operating new buildings. Students are demanding this type of environmental responsibility, and many prospective students have even made it a key decision point in their final college selection process.

For several decades, LEED (Leadership in Energy and Environmental Design) certification from the U.S Green Building Council has been the gold standard in rating environmentally responsible or “green” buildings. Today a lesser known standard, Passive House, is gaining more attention—especially from college facility planners thinking about constructing a new residence hall.

Passive House, a building standard that takes direct aim at improving energy efficiency and used for decades in single-family home construction, is now being used in new residence halls. Wheaton College’s new residence hall is the first large-scale Passive House dormitory in New England and just opened for this fall semester.

The Wheaton Passive House residence hall is expected to use 70 percent less energy than it would if built in a traditional manner. It is also designed to utilize solar panels (not yet installed) to produce 75 percent of its own power in the future.

The Goal of Passive House

The goal of Passive House is to build structures that are designed with the intent of creating a continuous, airtight, adiabatic envelope to increase energy efficiency and decrease the environmental footprint.

PHOTO COURTESY OF COMMODORE BUILDERS

Both Passive House and LEED can be used for all types of buildings and projects. While Passive House focuses primarily on energy efficiency, LEED certification includes several categories aimed at promoting a greener building overall. LEED evaluation criteria are: location and transportation, sustainable sites, water efficiency, energy and atmosphere, materials and resources, indoor environmental quality, and innovation.

Passive House, like LEED, focuses on a cradle-to-grave outlook, and gives preference to locally sourced materials and materials that have a low carbon footprint in their acquisition, procurement, and eventual disposal.

However, one of the major differences between LEED and Passive House is that LEED is prescriptive, while Passive House is performance-based. LEED provides a checklist to be followed during design, and as long as the appropriate boxes on the list are followed, the building can be certified. Even if the Passive House structure is built to the Passive House design specifications, if the building can’t pass the air-tightness tests at the end of construction, the building won’t be certified. Being required to prove that both the design and the constructed building meet Passive House Institute U.S. requirements adds to the importance of close coordination from design through to project completion.

PHOTO COURTESY OF COMMODORE BUILDERS

Passive House Standards and Benefits

It is important to note that Passive House standards are location- and climate-specific, meaning that a building in New England is constructed with different climate needs than a building in Southern California—contributing to each building’s comfort level.

Since Passive House focuses so intently on energy conservation, the long-term savings for colleges and institutions in terms of energy usage and money may be greater than a LEED-certified building.

A significant added benefit of a Passive House structure is the consistency of the temperature throughout the entire space. Frequently some rooms in residence halls will be too warm, so students may open the windows while those in another part of the building are cold. Passive House maintains the entire building at a constant temperature, and it doesn’t take much adjustment in the HVAC system to go from 68 to 70 degrees.

As a result, residents are less likely to complain about a room being too hot or too cold. In the case of a Passive House-constructed residence hall, this can mean fewer maintenance calls and, therefore, a possible reduction in maintenance costs.

A Passive House Plan at Wheaton College

In planning for a new residence hall, Wheaton College officials sought to build a high-performance structure as part of the college’s overall commitment to sustainability. A project-planning committee member mentioned having heard about Passive House, which prompted college officials to learn more and pursue Passive House early in the design phase.

PHOTO COURTESY OF COMMODORE BUILDERS

The Wheaton Passive House residence hall, a new 45,000-square-foot, four-story steel-and-plank building with an approximately 12,000-square-foot footprint, added 178 new beds to the campus and enabled the college to promote its commitment to environment and sustainability.

Five main principles were integrated into the design of the new residence hall at Wheaton:

1. Solar orientation
2. High insulation
3. High-performance windows
4. Airtight enclosures
5. Balanced ventilation with heat recovery

With these principles in mind, triplepane windows, special doors and molding, extra-thick walls, and insulation meeting the Passive House standard for the New England climate were all used in the Wheaton residence hall.

While the building doesn’t look much different from a traditional type of residence hall, the exterior doors are a little heavier, and careful observers might notice the triple-paned windows or, standing at the window, that the building walls are thicker. Unlike traditional radiator locations on the window wall, the heating and cooling units in each of the Wheaton residence hall rooms are placed on the wall opposite the windows.

PHOTO COURTESY OF COMMODORE BUILDERS

A factor that made the construction at Wheaton more complex was the fact that the first floor of the new building was planned as a campus-wide community space—and therefore was not designed to be Passive Housecertified. This created a unique set of challenges in wrapping the building to ensure the upper three floors were airtight. Think of it as if the top three floors were put in a Ziplock bag, which had to be connected to another Ziplock bag that was left partially open.

A Collaborative Process

The Passive House construction process itself necessitates close collaboration. The entire design and construction team on the project, including SGA architects, Commodore Builders, Thorton Tomasetti Passive House consultants, all of the subcontractors, and the Wheaton College facilities management team needed to be in lock-step throughout the planning and construction process, and everyone continually crosschecked with each other throughout.

Advanced Building Analytics, the firm responsible for rating the project according to Passive House criteria, typically runs tests at the beginning, various points during, and the end of construction. To ensure the building would attain Passive House certification, Advance Building Analytics also attended meetings with the full design team and subcontractors throughout. Though this firm was directly engaged by the college, Wheaton officials were also eager to take all steps necessary to ensure successful Passive House certification on this time-sensitive construction project.

Although upfront costs could be higher, there is no question that there are long-term benefits to both Passive House and LEED. For colleges seeking to capitalize on the latest trend to attract students while maximizing these savings, Passive House is definitely an option that should be considered for residence halls.

This article originally appeared in the College Planning & Management September 2019 issue of Spaces4Learning.