Passive House: A closer look at this sustainable certification and our experience with it

WALSH is more than a company of builders; we are a forward-thinking company dedicated to sustainability in construction.

This dedication has led us to becoming experts in the field with a project portfolio that includes the largest commercial Living Building in the United States, 123 total LEED certified buildings, 75 Evergreen Sustainable Development Standard (ESDS) certified affordable housing projects in Washington, 23 Earth Advantage certified affordable housing projects, and a number of others achieving standards such as Architecture 2030 Challenge, Salmon Safe, EPA Energy Star Challenge, and even one Zero Energy Ready project.

A big reason for our success in this effort is through the oversight and attention to detail offered by our in-house Quality Control/Quality Assurance department. Founded decades ago, and currently led by Sharon Libby Eyerly who has been part of the quality team since 2013 and holds the credential of being a PHIUS Certified Builder (CPHB), the Quality department began as a way to establish a collaborative approach to enclosure design documentation and execution in the field and is now implemented on all of our projects – not just the Passive House ones. The Quality team makes a strong force in combination with our Innovation team, our highly skilled self-performed division RDF Builders, and an entire company dedicated to enhancing the communities in which we work.

“We didn’t need any new tools or techniques to become proficient in Passive House construction, just a lot of teamwork and integrated design and construction work, with everyone pulling in the same direction toward the Passive House goals.”

– Mike Steffen, former WALSH Quality Director and current Preconstruction and CEDC Director.

Our buildings are consistently outperforming local airtightness building standards and delivering durable, energy efficient and healthy places to live. Through this careful and collaborative approach, we’re seeing many of our projects edge closer and closer – or even achieve – Passive House performance.


What is Passive House?

“Passive House is a building standard that is truly energy efficient, comfortable and affordable at the same time. Passive House is not a brand name, but a tried-and-true construction concept that can be applied by anyone, anywhere.”Passive House Institute

A concept that began in Germany as a way to create more efficient homes has steadily expanded across Europe to office buildings, supermarkets, schools, churches, factories and hospitals. Recently, the Passive House movement across the United States has surged, as the design and construction industry seek to move towards zero-carbon. To date, the Passive House Institute of the United States (PHIUS), the body which oversees Passive Building standards in the U.S., has certified more than 7.4 million square feet of Passive Building projects, as well as over 1,700 Passive Building consultants.

Passive House buildings make efficient use of the sun and strategic shading to heat and cool the buildings, allowing for energy savings up to 90%*. This is attained by utilizing special windows, extremely airtight building enclosures, highly insulated roofs, floor slabs and exterior walls, in addition to ventilation systems that supply constant fresh air.

Currently holding two Passive House-certified projects, with two more recent projects seeking certification, WALSH joined the movement back in 2015 with our Orchards at Orenco project, named the largest Passive House project in the country at the time.

Read on to learn about this project as well as our two more recent Passive House projects: Terwilliger Plaza in Portland, Oregon, and Hobson Place in Seattle, Washington.


Orchards at Orenco Phases I & II:

Orchards at Orenco is a high performing, energy-efficient and transit-oriented workforce housing complex in the Orenco Station neighborhood of Hillsboro, built for owner/developer REACH CDC. The largest Passive House building in North America at the time, Orchards was awarded Best Affordable Passive Building and also awarded Best Overall Passive Building Project by PHIUS in 2015.

The first 58,000 square foot phase of the Orchards at Orenco development, designed by Ankrom Moisan Architects, included 57-units, a playground, garden area, parking lot and landscaping. Phase II of the project involved new construction of an additional 58 units in a 49,500 square-foot, three-story structure. Our project team was able to rework the floor plans for the second phase, shaving off square footage and reducing the cost per unit by 8 percent.

Both phases received the Passive House certification. At the time, the cost for Passive House requirements added an 11 percent premium to construction costs, totaling $9.1 million for Phase I. This was offset by our ability to significantly reduce Phase II’s premium, with costs totaling $8.5 million. The project included triple-paned windows, insulation reaching 12-inches deep in the walls and four inches of foam under the floor slabs, a devoted ventilation system and shading devices.

Attaining these results began with a client who set a goal and continued with the entire team’s willingness to roll up their sleeves to figure out how to get it done. Extensive preconstruction work from the entire project team set the stage for success. Our self-performed building envelope crews from RDF Builders installed the air barrier system, including special tapes and sealants, with a keen eye on the details.

Read more:


Terwilliger Plaza:

Designed by LRS Architects, the project broke ground for not-for-profit, Terwilliger Plaza, a continuing care retirement community for residents 62 and over, in the Spring of 2021 and is scheduled for completion in 2023.

Taking up the full block south of OHSU, bounded by Southwest Fifth and Sixth avenues and Sheridan and Caruthers streets, this 10-story (plus one level of underground parking), 367,000 square-foot senior housing building boasts 127 high-end home units. Each one will have one or two bedrooms and full kitchens as well as balconies, along with simple maintenance and operation for the entire building. Thirteen floor plans will range in size from 1,029 square-feet to 2,310 square-feet.

As the largest Passive House building in the western United States, and the largest senior living Passive House, the project sets a new innovative, all-electric, and energy efficient standard for high-rise communities. Set to use 50 percent less energy than a current energy compliant building, this goal is achieved by a tight building envelope, an array of rooftop solar panels, superior air handling, in addition to green roofs, green living walls. The project boasts 100 percent continuous preconditioned fresh air circulation, allowing for interior spaces that will be substantially more healthy, quiet and thermally comfortable than those in conventional buildings.

“Our engineering analysis and design was bolstered by an integrated team that shared a vision for a unique senior living community. By achieving Passive House goals, the project showcases how these principles balance cost, energy-efficiency, occupant comfort, and long-term carbon savings.”

Ruwan Jayaweera, Principal at PAE, critical team member on the project.

Some features that allow this certification include improved wall R values; triple-pane windows; lighting power reduction; eco-friendly appliances; outdoor air systems with heat recovery; high-performance HVAC-VRF; heat pump water heaters; low-flow fixtures; and significant thermal bridging details at balcony connections, balcony edges, parapet connections and exterior walls to concrete slabs.

Each resident will enjoy the added features attained from the efficient design along with a variety of multipurpose rooms, public living rooms, lounges, sunrooms and lobbies. Outdoor spaces include a courtyard and landscaped rooftops, not to mention the stunning views of the mountains.

“Our involvement with the Parkview expansion and the community of people in which it serves aligns with our values to create buildings with enduring value, a dedication to sustainable practices, and building strong communities.”

– Craig Leonnig, WALSH Senior Project Manager on the project.

Read more:

Hobson Place:

Hobson Place is a story of firsts: the first facility in Washington State to combine primary healthcare, mental healthcare, and permanent supportive housing; and the first supportive housing project in Washington State to achieve Passive House certification – this building produces as much energy as it uses, reducing overall energy use by 40 percent.

Located in Seattle, Washington one block off Rainier Avenue and less than a quarter mile from the future Judkins Park Sound Transit Station and designed by Runberg Architecture Group, Hobson Place provides permanent supportive housing for 177 individuals exiting homelessness. The project combines independent living with wrap-around services – including on-site caseworkers, a computer lab, and a 24,000 square-foot facility for primary and behavioral healthcare that serves both residents and the community.  Phase one of the project was completed in October 2020, adding 85 affordable studio apartments, while Phase two added 92 apartments and an integrated health clinic – made possible through owner DESC‘s partnership with Harborview Medical Center .

The project applies many different strategies to maximize its efficiency: minimized building air leakage, energy recovery ventilators, thermostats that are interconnected with window sensors, a hot water heat plant powered by heat pumps instead of fossil fuels, bioretention planters to manage stormwater control, improved thermal insulation, high-efficiency LED lighting coupled with occupancy sensors, and a 40kW photovoltaic array provided on the roof. The residential portion of the building targeted an aggressively low Energy Use Intensity (EUI) of 18.4, which indicates the energy usage per square-foot. Similar residential buildings of the same size typically achieve an EUI of 40 in the City of Seattle, and averages of 59 nationwide.

“There were many aspects of this project that really challenged some Passive House measures: commercial, larger scale construction in general, and Hobson Place specifically. We tried to summarize and group those into as few F-words as possible: function, funding and form.” Sharon Libby Eyerly explains while diving into more detail on the construction process on Passive House Accelerator Live.

Sharon Libby Eyerly, WALSH Quality Director joined Greta Tjeltveit of Evergreen Certified on Passive House Accelerator Live to talk about Hobson Place.

Bottom line, she says:

“Sequencing is key, but it’s the early planning that really pays.”

And through our diligence, we were able to successfully deliver this project not only on time, but even under budget.

Read more:


In Closing

WALSH Preconstruction & CEDC Director, Mike Steffen, presenting “Exploring a Path to More Cost-Efficient, Energy-Efficient (Passive House) Affordable Housing” at the 2019 Passive House Northwest Annual Conference: 10 Years of Building Beyond Zero.

In an effort to help our affordable housing and non-profit partners achieve efficient results in a cost-effective way, our team took things a step further by developing what we call Cost Effective Design and Construction (CEDC). This approach standardizes the basic elements and components that go into affordable housing design – an approach which, when utilized, has seen cost savings results of up to 25% savings.

With global and local goals to reduce our footprint, we are glad to be in the Pacific Northwest, the sustainable epicenter in the nation, during this time of refocused efforts. Our knowledge of the climate combined with our local legacy and strict mission to improve our communities and serve our clients with the highest quality building possible places us as a great strategic partner on your next project, or simply as someone to have a conversation with and share our experiences and lessons learned. We all need to work together to see more buildings embrace the performance goals of Passive House in our future.