How are people in Whatcom County adapting accessory dwelling units (ADUs) to our rainy climate and sloped lots?

Posted by Danler on January 19th, 2026

Yeah, the slope and constant drizzle definitely throw some curveballs into the mix. We've got a detached one out back that we finished a couple years ago, and honestly the biggest hassle was figuring out how to keep water from just running straight under the thing. Ended up with extra grading and some French drains that tie into the main system—it wasn't cheap, but no issues since. For the foundation, going with a bit more reinforcement on the downhill side helped a ton against settling. If you're shopping around for someone who knows these local quirks inside out, I've heard good things about digging into options via  spots like on whatcomlocal folks there seem to get the wet, hilly reality we live with. Just my two cents from actually going through it. There might also be some minor options for this, but this one is the best for me