Seattle DADU cost estimate

[Daniel Ulie]

Hi all,

First time poster here. Have a question for those knowledgable about building out a DADU in Seattle.

I would like to build out the approved 800 sq foot pre-approved Seattle DADU design and am knee deep in the price estimate process. I could really use some help from experienced folks so I know exactly what I'm getting into.

So far I have cost estimates on feasibility ($500), permitting ($1000), general contracting labor (200K give or take), cost of building materials ($140,000), and loan interest (Still working on getting an estimate on this) Can someone help fill in the blanks of everything else I'll need and what I should budget for? And if the cost estimates I just listed seem reasonable?

Looking for help on budgeting construction work a GC typically will not do (plumbing, electricity) and other costs I may be overlooking. Thanks!

-Dan