Homeowners in the U.S. can build and improve their homes to be more resilient to increasing climate extremes. We aim to educate homeowners about climate-related risks and opportunities to reduce potential damage to homes and save lives.
In this series of Stories, we share examples of homes built to withstand local climate risks. This blog focuses on a project designed to be a safe home for wildfire victims.
The RESTORE Passive House is a predesigned passive house aimed to replace homes destroyed in the Marshal Fire in Colorado in December 2022, which burned an estimated 1084 structures, and another 149 were damaged.
The team completed the design process, and the city of Boulder granted the permit for the first projects. The construction of two homes began on February 2023 in Boulder County, CO.
Andrew Michler, a passive house designer, acts as the passive house consultant and champion for these projects and helps design and develop an awareness of the passive house concepts and benefits. Michler cooperated with Joubert Builders, and Harrison Architects, an architect firm experienced in passive house construction, and led the consultant for the first certified passive house in Seattle.
The RESTORE passive house Colorado was designed primarily to address the climate risk of wildfires, smoke, and extreme temperatures for prolonged periods.
In recent years Boulder is experiencing more extreme temperatures and weather events, including a significant increase in the number of high-temperature summer days. A temperature above 90 degrees Fahrenheit is not uncommon anymore, even in the fall season.
In addition, the air quality in the region has decreased. Cooling houses by opening windows is no longer optimal due to smoke from wildfires, and other airborne conditions, such as the ozone. The ozone in the Denver metropolitan area in Boulder was downgraded from “serious” to “severe.” The ozone levels in the area are higher than EPA’s air quality standard, which can cause breathing-related issues such as bronchitis, emphysema, asthma, and skin and eye damage.
The Marshall Fire in Colorado was a collective wake-up call to wildfire risk within urban and suburban surroundings. While it occurred outside the Boulder City limits, it was the most destructive in Colorado history. The Marshall Fire happened mid-winter, which illustrates that there is no such thing as a fire “season” anymore.
Wildfires also pose a risk of smoke damage even to distant homes. The Marshall Fire Colorado caused severe smoke damage to many houses and prevented occupants from returning to their homes though their houses were not destroyed.
Climate Resilience Strategies
Passive House is well known for its extraordinary energy efficiency, which increases the home’s climate resilience. It is designed to maintain comfortable climate conditions for occupants without a significant need for heating or cooling. In power outages, a passive house can maintain livable temperatures for up to 36 hours, despite extreme temperatures outside. The main components that allow it are the airtightness of the house’s envelope and the thick and continuous insulation in the walls.
Passive houses are naturally more resilient to wildfires due to several characteristics based on the basic principles of the Passive House. Note that the strategies are fire resilient only if put together in a proper assembly.
The following are specific climate-resilient strategies specified in the Passive RESTORE House Design: