Future-Proofing Educational Facilities: The Passive House Design Solution
By Paul C. Hutton, FAIA, LEED Fellow, Principal and Director of Regenerative Design at Cuningham
High-performing, energy-efficient school facilities can serve a foundational role in uplifting students, staff and the greater community over the long term.
That said, complex environmental control systems are often implemented to achieve building performance goals related to energy efficiency and utility costs. These systems must be diligently maintained, or else they risk a decline in energy performance and an uptick in utility costs.
This upkeep requires a significant additional investment of finances and time, which most school districts (especially rural and small ones) do not have available to them.
The good news is that the solution for some facilities – depending on size, location and available resources – might be born out of the strategic implementation of a concept originating nearly 50 years ago: Passive House.
Strategically applying these design principles could be the key to achieving highly efficient, yet easier-to-operate, buildings that are “future-proofed” for success – with no additional budget.
This could be a game-changer for schools located throughout the country, especially in more rural areas without immediate access to resources. Beyond that, it could improve on more conventional approaches to sustainability on a wide scale and help facilitate the move toward regenerative design.
What is Passive House?
The “Passive House” design framework is really a series of principles that can be applied to all building types. Ultimately, it seeks to balance heat gains and losses to maintain an optimal comfort level through an energy-efficient process.
According to Passive House Institute US, Inc. (PHIUS), this is achieved through the implementation of the five building-science principles below:
- Employs continuous insulation throughout its entire envelope without any thermal bridging.
- The building envelope is extremely airtight, preventing infiltration of outside air and loss of conditioned air.
- Employs high-performance windows (double- or triple-paned windows, depending on climate and building type) and doors. Solar gain is managed to exploit the sun's energy for heating purposes in the heating season and to minimize overheating during the cooling season.
- Uses some form of balanced heat- and moisture-recovery ventilation.
- Uses a minimal space conditioning system.
The roots of the Passive House framework actually began in North America following the oil embargo of 1973, which tripled oil prices and sent the United States—and much of the Western world—into an energy crisis.
This prompted architects and engineers to seek innovative solutions to improve how the built environment consumes energy, including superinsulation and solar architecture. In 1982, American physicist William Shurcliff coined the term “passive house” to describe these methods.
While interest in the principles and energy conservation as a whole began to wane in the United States in the 1980s, Germany forged ahead. German physicist Wolfgang Feist improved upon the efficiency of Passive House design and eventually founded the Passivhaus Institute (PHI).
Today,Passive House principles continue to show promise as a key player on the road to achieving net-zero and net-positive energy goals.
Under the Passive House framework, the cost increases from an improved envelope are hopefully offset by the cost decreases from the resulting simplified HVAC system.
Passive House as a Solution for Educational Facilities
Educational stakeholders increasingly understand the importance of environmentally friendly, efficient facilities that will serve students and communities for decades to come. This has been a key factor influencing our school facilities’ architecture and design work in recent years.
In some cases, designs have had to adjust and evolve to meet new mandated standards. The first instincts of some project teams might be to implement environmental control systems that are often too complex to maintain and not feasible to operate in the long run.
In reality, many school districts—especially in smaller locations outside urban centers—do not have the budgets or access to the necessary resources to sustain high levels of performance for those systems over the long term.
Because of this, when approaching energy-efficient design for school facilities, project teams must ask themselves:
- Will the building really deliver the energy and cost savings promised?
- Are the new, sustainable systems built to last?
- Will staff possess the necessary expertise and access to resources to maintain a high-tech building?
For some school facilities, Passive House principles have emerged as a solution that allows us to ensure a “yes” to each of the above questions.
For example, we recently designed a new campus for Sierra Grande School, a PK-12 public school currently under construction in Blanca, Colo. (located three hours outside the closest major city, Colorado Springs).
The project is funded by Colorado’s Building Excellent Schools Today (BEST) grant, a critical program that allows communities in need to replace older, deteriorating educational facilities. As a BEST project, the school is required to meet the state’s High Performance Building Certification Program (HPBC). Cuningham and our engineering partner BranchPattern recognized that it was necessary to rethink the traditional process.
We understood that designing a high-performance, efficient and simple-to-maintain facility was an important component of the overarching goal of creating a competitive educational experience that would help the community further establish its identity and thrive.
Rather than attempting to pursue an advanced mechanical system that compensates for an average building envelope, we worked with an independent cost estimator to identify and evaluate another solution.
We eventually brought the concept of Passive House to the client because the site’s remoteness, climate zone (Passive House makes the most sense in colder climates, typically mid-latitude and above) and utility availability made it a good candidate for this design framework.
Sierra Grande School in Blanca, Colo.
Making the Vision a Reality
After determining that a Passive House approach will work for a particular educational facility project, strategic implementation will ensure a successful and cost-effective result.
Within the design framework, a high focus must be put on the insulating qualities of the school’s envelope components. Materials must be carefully procured based on their impact on energy use, durability and affordability.
Passive House projects also will have at least some insulation under the entirety of the building’s foundation. As an example, at Sierra Grande School, we implemented a flexible roll sub-slab insulation product. This provided the all-important thermal break and is the easiest for the contractor to install, thus saving time and money.
Ultimately, with Sierra Grande, we were also able to design a building envelope suited to Blanca’s cold climate that works with an HVAC system that is 100 percent electrical – at a cost difference of less than 1 percent of the total construction budget. The envelope is so efficient—the walls, roofing and windows all have approximately twice the insulation R-values of recent BEST projects—that the HVAC system no longer needs a boiler, chiller or perimeter heating. It uses simple components familiar to any technician, better ensuring it will never go too long without proper upkeep.
And because of this, there is minimal risk of untended systems decreasing in performance and increasing utility usage over time.
Looking Ahead
As we’ve continued to see successful applications of the Passive House framework, we believe that this will be part of the future for sustainable schools – allowing for simple-to-operate, easy-to-maintain facilities that provide extremely low utility bills and a comfortable environment for learning.
Simplifying a building’s energy systems through the Passive House framework goes beyond a cost-saving measure for educational facilities. It “future-proofs” for success by saving school staff time (and headaches), as it eliminates the worry that comes with not having the adequate expertise or resources at their disposal to maintain complicated, high-efficiency energy systems.
With more and more momentum arising around net-zero energy, we anticipate that Passive House will become one of the ways of getting there. It is ultimately based upon a sound core approach – keep systems simple, and invest dollars in components that don’t wear out.
Paul C. Hutton, FAIA, LEED Fellow, is a Principal and Director of Regenerative Design at Cuningham, an award-winning national design firm dedicated to creating impactful and aspirational designs by working with our communities and focusing on restoring our Earth. Founded in 1968, Cuningham provides architecture, interior design, urban design, and landscape architecture services for a diverse array of client and project types, including living, healthcare, education, hospitality, workplace, and entertainment. The firm has offices in Denver, Las Vegas, Los Angeles, Minneapolis, Phoenix, and San Diego.