Accessory dwelling unit massachusetts — San Francisco, CA

Last updated: September 24, 2026

What affects the price

Building an ADU is a major project, and the final bill depends on a few key things. Site prep is a big factor; if your land is sloped or needs extensive utility connections, costs go up. The materials you choose—from siding to kitchen finishes—also change the math significantly. Whether you’re building a detached unit or converting an existing garage shifts the permit requirements and structural work needed. We provide exact pricing confirmed free on the call.

About this service

This refers to the specific zoning laws and building codes that govern secondary units within Massachusetts. If you own property in the state, you need to navigate these local regulations to ensure your project is legal and compliant. Requirements vary significantly by town regarding size limits and occupancy rules. We help you interpret these local ordinances to see what is possible on your specific lot. Exact pricing confirmed free on the call.

Frequently asked in San Francisco

Also serving nearby: Daly City · Richmond · San Mateo · Berkeley · Oakland

All cities in California →

More on this: HUD ADU resources — ADU policy and financing research.

Service area details

Serving all of San Francisco — population 808,988; about 17,323 residents per square mile across 46.7 sq mi. ZIP codes covered include 94102, 94103, 94104, 94105, 94107, 94108, 94109, 94110.

Neighborhoods served in San Francisco: The Sunset District, The Marina, Nob Hill, The Richmond District, Hayes Valley — and every surrounding area.