Cost of accessory dwelling unit — Washington, DC

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

Building an ADU involves several variables that influence the total investment, including your local site conditions, utility hookups, and the finishes you select for the interior. We focus on transparency throughout your project planning to keep you on budget. Exact pricing confirmed free on the call.

Frequently asked in Washington

Also serving nearby: Alexandria · Baltimore · Richmond · Reading · Philadelphia

All cities in District of Columbia →

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

Service area details

Serving all of Washington — population 678,972; about 11,107 residents per square mile across 61.1 sq mi. ZIP codes covered include 20001, 20002, 20003, 20004, 20005, 20006, 20007, 20008.

Neighborhoods served in Washington: Georgetown, Capitol Hill, Dupont Circle, Adams Morgan, Shaw, Woodley Park — and every surrounding area.