I recently got quotes for converting a workshop into an accessory dwelling unit (ADU), and I'm wondering if I'm overreacting to the prices. Back in 2020, I bought a home with a big workshop that has the potential for conversion. The workshop has some infrastructure already, like a ductless mini-split and a toilet, but I'd need to bring it up to code, which involves shifting a wall and adding footers. The quotes are staggering: just for moving the wall, I was quoted over $20,000, and to get it livable, I'm looking at around $120,000 to $200,000! I initially thought I could do the whole thing myself for around $30,000 to $40,000 since I have experience doing similar projects, but now I'm not sure. Are these prices just outrageous or am I being unrealistic about my DIY plans?
3 Answers
If you're in California, make sure to check the State ADU laws. Sometimes they allow you to convert existing non-conforming structures without too much hassle, which could save you a lot of costs. Look into it!
I feel like $30-40k for the entire project seems pretty low, especially with the current market. But then again, $400/sq ft for the build is outrageous! I’d recommend getting more quotes to see if you find something better.
It's definitely worth getting multiple bids to see if you're getting ripped off or not. Prices can vary a lot based on quality and market demand, so having a few quotes will help you gauge what's reasonable.

I’m actually in Washington, so I'm not sure how that might affect everything.