Detached accessory dwelling unit — 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
A detached ADU is a standalone building separate from your main house, like a backyard cottage or converted garage. You need this type if you want maximum privacy and don't want to renovate your existing home’s interior. Pricing for detached units is influenced by site excavation, electrical trenching, and the size of the footprint. Exact pricing confirmed free on the call.
Frequently asked in Boulder
What are 24-hour ADU services?
Who is an accessory dwelling unit contractor in Boulder?
What are homes with in-law suites like?
Homes with in-law suites, often called ADUs, have a separate living space. This space includes a kitchen, bathroom, and bedroom. They offer privacy and independence for residents. We can help you build one.
What's the best accessory dwelling unit for my home?
The best ADU for your home depends on your property and needs. Options include detached units, garage conversions, or additions. We can help you explore suitable choices. Local pros can provide tailored recommendations.
Are there ADU options in Massachusetts?
How do I get an ADU quote?
What's the accessory dwelling unit construction cost?
The construction cost for an ADU in Boulder varies based on size, design, and materials. Site preparation and utility hookups also influence the price. We can help you get an accurate estimate from local builders.
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: Baseline, Newlands, Mapleton Hill, Gooch Hill, Chautauqua — and every surrounding area.
Areas we serve
Browse by state, then city.