Adu building — Boulder, CO
Last updated: September 24, 2026
What affects the price
Building an ADU involves variables that shift your total investment. The footprint size and complexity of the architectural design are primary factors. Are you planning a detached unit that requires new utility trenching, or is this a garage conversion that uses existing plumbing? Site accessibility, soil conditions, and your choice of finishes—like luxury flooring versus standard options—also play significant roles. Permitting fees vary widely depending on your local municipality and current zoning requirements. Exact pricing confirmed free on the call.
About this service
The construction process for an ADU involves taking a project from the initial design phase through final inspections. You need this service when you are ready to convert a garage, build a basement apartment, or construct a new detached unit. It covers everything from foundation work and framing to utility hookups and interior finishing. Costs depend on the size of the unit and the complexity of your site. Exact pricing confirmed free on the call.
Frequently asked in Boulder
Can I get a prefabricated accessory dwelling unit in Boulder?
What's the process for accessory dwelling unit rental in Boulder?
Are there affordable accessory dwelling unit options in Boulder?
What's involved in accessory dwelling unit construction in Boulder?
Can I build a backyard accessory dwelling unit in Boulder?
What's the cost to build an accessory dwelling unit in Boulder?
What are accessory dwelling units (ADUs)?
Also serving nearby: Longmont · Westminster · Arvada · Thornton · Lakewood
More on this: HUD ADU resources — ADU policy and financing research.
Service area details
Serving all of Boulder — population 105,898; about 3,937 residents per square mile across 26.9 sq mi. ZIP codes covered include 80301, 80302, 80303, 80304, 80305, 80306, 80307, 80308.
Neighborhoods served in Boulder: Downtown Boulder, Mapleton Hill, Whitin Park, Chautauqua, Newlands — and every surrounding area.
Areas we serve
Browse by state, then city.