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
An accessory dwelling unit permit is the required authorization from your local planning department to build on your lot. This paperwork confirms your plans follow zoning rules and structural safety standards. You need this service if you are in the planning stages of your backyard project.
Frequently asked in Columbia
What are affordable ADU options in Columbia?
What is the best accessory dwelling unit for Columbia?
What is the cost to build an accessory dwelling unit in Columbia?
What ADU services are available in Columbia?
What does accessory dwelling unit mean in Columbia?
What are homes with mother-in-law suites in Columbia like?
What is an accessory dwelling unit for rent in Columbia?
Also serving nearby: O Fallon · Independence · Lee S Summit · St Louis · Kansas City
More on this: HUD ADU resources — ADU policy and financing research.
Service area details
Serving all of Columbia — population 129,330; about 1,921 residents per square mile across 67.3 sq mi. ZIP codes covered include 65201, 65202, 65203, 65205, 65211, 65212, 65215, 65216.
Neighborhoods served in Columbia: The District, Campus District, West Blvd, Rock Quarry — and every surrounding area.
Areas we serve
Browse by state, then city.
