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 is the physical process of building a secondary unit, which requires coordinating contractors, electricians, and plumbers. You need professional construction services when you are ready to break ground on your design. Costs are driven by the complexity of the foundation, interior finish levels, and site grading requirements. Exact pricing confirmed free on the call.
Frequently asked in Columbia
What is the process for accessory dwelling unit construction in Columbia?
Where can I find accessory dwelling unit contractors near me in Columbia?
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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: Downtown Columbia, South Columbia, West Columbia, The District, The Highlands — and every surrounding area.
Areas we serve
Browse by state, then city.
