Building Science for the Pacific Northwest

Homes in Washington face one of the wettest, most challenging climates in the country.
This section explains—in clear, simple language—how water moves through a home, where failures start, and what it takes to build or remodel for long-term durability.

Whether you’re planning an ADU, renovating a 1960s house, or trying to solve a persistent moisture issue, these guides will help you understand how your home really works.

Crawl Spaces
Basements
Walls + Insulation
Roofs + Attics
Windows + Flashing
Decks + Ledgers
Moisture 101
Drainage + Site Water
Flat Roofs (specific to PNW failures)
ADU Building Science