Opportunity Village is a transitional micro-housing village that serves 30 otherwise unhoused individuals and couples at a time. The homes range from 60 – 80 square feet in size, and utilize common cooking, restroom, and gathering facilities on site. The project is located on city-owned land, operating on short-term leases for a nominal fee. It was permitted as a “homeless shelter” in an industrial zone. The individual homes were permitted as “temporary structures” and “sleeping units,” rather than as permanent dwellings, which relaxed several code requirements.
We reduced air leakage and thermal bridges by replacing our through-roof plumbing waste piping vent system with a combination of air admittance valves (AAV) and a two-way, filtered outdoor valve. Oregon’s plumbing code recognized AAVs, but restricted their use to 3 per house and required one through-roof vent. On appeal, the City of Portland allowed us to install AAVs according to manufacturer’s guidelines so we could eliminate all through-roof vents, using the “alternate materials and methods” provision through its Alternative Technology Advisory Committee (ATAC) process.