Passive House, an ultra-efficient building standard that originated in Germany, has been used for single-family homes since its inception in 1990. Only recently has the concept made its way into the commercial market.
The Passive House standard requires buildings to use at least 80% less energy than a comparable conventional building, so air tightness is a must. The structure must be completely sealed against any air infiltration, at the same time preventing conditioned air from escaping. This means Building Teams must employ multiple layers of insulation in the walls, roof, and flooring, plus continuous air barriers and reliable windows and doors.
Once the building is completely sealed, a number of techniques can be engaged to regulate the temperature. Energy-recovery ventilators may be employed to keep a constant supply of fresh air circulating throughout the home. These heat exchange systems typically recycle the heat of exhaust air from kitchens and bathrooms by filtering it through the fresh air entering from the outside. This saves energy costs.
An analysis of the site and its climate also must also be completed. Effective planning of the window orientation can have a direct impact on the amount of natural daylight that will penetrate the space. Shading devices can be designed to control the amount of sun entering the space at any given time, which can contribute to heat gain.
Passive House enters the hospital sector
The Passive House concept is also spreading to other nonresidential sectors. The machinery and lighting required to run hospitals make them the largest users of energy across commercial sectors. In the Hoechst district of Frankfurt, Germany, a hospital renovation is set to become the first Passive House hospital in the world.
The state of Hesse completed a baseline study to determine the methods for executing such a large-scale PH project. The study notes that ventilation, heating and cooling, water, hygiene, and food service should all be considered when planning building systems around the Passive House standard in a healthcare setting. The study recommends the use of energy-efficient equipment, but notes that many medical devices have not yet been rated for their energy efficiency.
In multifamily buildings, the ratio of interior livable space to building envelope size is greater than that of a single-family home, so the envelope work is somewhat less demanding. Even so, the number of windows, doors, and balconies in multifamily projects means even more areas of the façade are vulnerable to air infiltration and expiration.
Despite these difficulties, commercial Building Teams are rising to the challenge. According to the Passive House Institute U.S., as of June 2014, 21 multifamily projects have been submitted for PHIUS Passive House certification: four have been fully certified, another four have been precertified and are under construction.
Stellar Apartments, Eugene, Ore., was the first multifamily project to achieve certification. Designed by Bergsund DeLaney Architecture & Planning for the St. Vincent de Paul Society of Lane County, this low-income housing project consisted of the construction of two nearly identical buildings.
The first, built to the Eugene Water and Electric Board’s Earth Advantage Standards, was designed to save 15% more energy versus a home built to code. The Building Team designed the second building to Passive House standards. The two buildings have identical floor plans, with six units on two stories, and are oriented in the same direction with similar shading. The main difference between them is the air tightness and the use of an energy-recovery system in the Passive House building.
The buildings were completed in July 2013, and are under study by students at the University of Oregon. The researchers will compare the energy use and cost savings, air quality, light quality, and acoustics of the buildings to determine whether a significant difference exists.
Stellar Apartments in Eugene, Ore., consists of two nearly identical low-income apartment buildings built to different sustainable standards. One meets the city’s Earth Advantage Program requirements, while the other (pictured above and left) is the first multifamily building to achieve Passive House certification. The Building Team included St. Vincent DePaul Society of Lane County (owner), Bergsund DeLaney Architecture & Planning, Hohbach-Lewin Inc., Poage Engineering, and Dougherty Landscape Architects. Photo: courtesy Bergsund DeLaney Architecture & Planning
The Orchards at Orenco is currently under construction in Hillsboro, Ore. Phase 1 of this affordable housing project, owned by REACH Community Development, includes 57 units, making it the largest precertified Passive House building to date.
The facility will employ traditional methods of Passive House construction—a continuous air barrier, extra insulation, and heat recovery system—to achieve up to 90% reduction in energy bills for the tenants. The roof will be light in color to reflect solar heat; it will have a foot of insulation, which is almost four times that required by the local building code.
The Building Team is using triple-pane glazed windows, with European-style tilt-turn operation. It is common for Passive House buildings to use windows made in Europe, as double-hung or slider windows manufactured in the U.S. do not offer the tightness required for PH certification.
Building Teams can apply some of the principles to multifamily projects, regardless of whether they are able to achieve full certification. Extra insulation, greater attention to detail when sealing the building envelope, and energy-efficient heating and cooling systems can have a positive effect on a building’s performance regardless of whether the building is able to carry the Passive House label.
Related Stories
MFPRO+ News | Jun 24, 2024
‘Yes in God’s Backyard’ movement could create more affordable housing
The so-called “Yes in God’s Backyard” (YIGBY) movement, where houses of worship convert their properties to housing, could help alleviate the serious housing crisis affecting many communities around the country.
Student Housing | Jun 20, 2024
How student housing developments are evolving to meet new expectations
The days of uninspired dorm rooms with little more than a bed and a communal bathroom down the hall are long gone. Students increasingly seek inclusive design, communities to enhance learning and living, and a focus on wellness that encompasses everything from meditation spaces to mental health resources.
Museums | Jun 20, 2024
Connecticut’s Bruce Museum more than doubles its size with a 42,000-sf, three-floor addition
In Greenwich, Conn., the Bruce Museum, a multidisciplinary institution highlighting art, science, and history, has undergone a campus revitalization and expansion that more than doubles the museum’s size. Designed by EskewDumezRipple and built by Turner Construction, the project includes a 42,000-sf, three-floor addition as well as a comprehensive renovation of the 32,500-sf museum, which was originally built as a private home in the mid-19th century and expanded in the early 1990s.
Building Technology | Jun 18, 2024
Could ‘smart’ building facades heat and cool buildings?
A promising research project looks at the possibilities for thermoelectric systems to thermally condition buildings, writes Mahsa Farid Mohajer, Sustainable Building Analyst with Stantec.
University Buildings | Jun 18, 2024
UC Riverside’s new School of Medicine building supports team-based learning, showcases passive design strategies
The University of California, Riverside, School of Medicine has opened the 94,576-sf, five-floor Education Building II (EDII). Created by the design-build team of CO Architects and Hensel Phelps, the medical school’s new home supports team-based student learning, offers social spaces, and provides departmental offices for faculty and staff.
Healthcare Facilities | Jun 18, 2024
A healthcare simulation technology consultant can save time, money, and headaches
As the demand for skilled healthcare professionals continues to rise, healthcare simulation is playing an increasingly vital role in the skill development, compliance, and continuing education of the clinical workforce.
Mass Timber | Jun 17, 2024
British Columbia hospital features mass timber community hall
The Cowichan District Hospital Replacement Project in Duncan, British Columbia, features an expansive community hall featuring mass timber construction. The hall, designed to promote social interaction and connection to give patients, families, and staff a warm and welcoming environment, connects a Diagnostic and Treatment (“D&T”) Block and Inpatient Tower.
Concrete Technology | Jun 17, 2024
MIT researchers are working on a way to use concrete as an electric battery
Researchers at MIT have developed a concrete mixture that can store electrical energy. The researchers say the mixture of water, cement, and carbon black could be used for building foundations and street paving.
Codes and Standards | Jun 17, 2024
Federal government releases national definition of a zero emissions building
The U.S. Department of Energy has released a new national definition of a zero emissions building. The definition is intended to provide industry guidance to support new and existing commercial and residential buildings to move towards zero emissions across the entire building sector, DOE says.
Multifamily Housing | Jun 14, 2024
AEC inspections are the key to financially viable office to residential adaptive reuse projects
About a year ago our industry was abuzz with an idea that seemed like a one-shot miracle cure for both the shockingly high rate of office vacancies and the worsening housing shortage. The seemingly simple idea of converting empty office buildings to multifamily residential seemed like an easy and elegant solution. However, in the intervening months we’ve seen only a handful of these conversions, despite near universal enthusiasm for the concept.
