Short answer
Bay Area residential architecture fees commonly depend on scope, project cost, complexity, and service level. Use ranges for planning only; the real number follows a defined brief.
| Item | Planning range | Notes |
|---|---|---|
| Initial consultation or feasibility | $300-$2,500 | Often fixed-fee; useful before a full engagement. |
| ADU plans / permit drawings | $4,000-$18,000+ | Higher when site constraints, custom design, or revisions pile up. |
| Home addition design and permit set | $12,000-$45,000+ | Structure, planning review, and consultant needs drive the spread. |
| Custom home architecture | 8%-15%+ of construction cost | Can be more for high-touch design and construction administration. |
How to use these numbers
Treat the ranges as planning context, not a quote. Bay Area homes punish lazy assumptions: existing conditions, utilities, structural scope, planning review, and consultant needs can move the number fast.