Homebuilding for Resiliency in 2019

Miriam Webster Definition of Resilience: An ability to recover from or adjust easilyto misfortune or change

By KATHERINE AUSTIN

Readers: you understand that climate change is real, you accept science, and understand burning fossil fuels and melting permafrost’s methane are main contributors. The burning of forests contributes by releasing stored carbon and eliminating photosynthesis. Now, it is time to address what we as architects, designers, builders, and developers can do to mitigate the threat of wildfires.

I live and work in the west. Our forests are tinder-dry from extended drought, making them subject to fierce wildfires driven by intense winds and fire’s own hurricane-force winds, even fire tornadoes. The horrific fires of 2017 and 2018 destroyed thousands of homes, businesses, and lives. This is personal to me. When I moved from Santa Rosa, California to Bend, Oregon in 2014, I was met by the Two Bulls Fire; it darkened the sky, turning the sun into a red, rubber ball; but was fortunately contained without loss of life or significant structure damage.

In 2017 the Tubbs fire in Sonoma County, Calif. raged through Santa Rosa just three hours after beginning in Napa County. Our son and daughter-in-law fled their home and could not return for weeks. They were fortunate that their home survived, but blocks away there was complete devastation. I designed a subdivision in Coffee Park, a flat and affordable area in Santa Rosa. The Tubbs fire jumped a six-lane highway to destroy nearly all of all of it, including the homes I designed. When visiting the site, I had to use Google Maps to make sure I was in the right place.

Few can wrap their heads around the total destruction of the Camp Fire of Paradise and the effects on communities around it. Thousands upon thousands of homes and businesses were destroyed and over 80 lives were lost. Yet if you look at some of the photos, you will notice that many of the trees surrounding these homes remain. It was the homes themselves that provided the fuel that drove the fire through those communities. What does this mean for our professions?

California Chapter 7A of the California Building Code (CBC) and Chapter R337 of the California Residential Code (CRC) deal with the Wildland-Urban Interface. For other states that have adopted the International Building Code, the 2018 International Wildland-Urban Interface Code, particularly the fifth chapter, contains the information you need to design for wildfire.

Before deciding to build, ask yourself if where you intend to build is appropriate. The incursion of the built environment into forests presents a
unique danger. Is owning a lot next to a tinder-dry forest worth the risk? Just because you can build does not mean you should. If you build you need to take responsibility, clear the land around to provide a safe perimeter, and provide multiple exits for quick evacuation. If you are rebuilding destroyed homes, you are likely already in a high or moderate fire zone and need to comply with the Wildland Urban Interface Codes. Even if you are not, and are in a low fire hazard area like Coffee Park, you may want to build to these standards anyway.

It is possible to help prevent what caused many of those homes to burn. I am designing several replacement homes for Santa Rosa. All of those homes were built in the 1970’s and their poor construction contributed to their demise. Several communities in California have provided quick online guides for homeowners and builders to follow and can be found with a Google search of WUI Regulations. I will quickly outline those main requirements but I advise you to study the appropriate building codes for a comprehensive set of requirements.

The most significant cause of homes combusting was embers sucked through vents into roofs and shattering non-tempered glass in windows due to extreme heat. Shake roofs, combustible cladding, and decks are tinder waiting to be lit. No wood members less than 2x are now allowed on exteriors. Stucco or cement-board siding is recommended. Fire racing up a hill will find its way under a home if exposed and under a deck. All cladding must now extend to grade and all vents must have wire mesh with no larger than 1/8” openings or baffles. Decks must be made of non-combustible assemblies. All windows must have one tempered pane. Cal Fire lists materials that meet the required standards to be used in the WUI zone. Metal roofs require underlayment to meet the fire code. Comp shingle roofs remain a good choice. Remember that the doors and garage doors must also meet minimum thickness and material requirements.

We can thoughtfully design for resilience in a fire zone.

To find out more, visit www.austinaia.com

Katherine Austin, AIA, Architect helps represent the Bend Section of the Oregon AIA and continues to be on the City of Bend’s Affordable Housing Advisory Committee. She can be reached at kaaustin@pacbell.net or 707-529-5565. To find out more, visit www.austinaia.com