Attached ADU near Thornton, CO
3R Services
10825 West 32nd Avenue, Wheat Ridge, CO 80033
13.7 miles
3R Services builds ADUs in Arvada, CO, including backyard cottages, garage conversions & in-law suites. Projects cost $80K–$250K, take 3–6 months, and include permitting, transparent pricing & a 1-year warranty.
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Studio Home by Studio Shed
1500 Cherry Street, Louisville, CO 80027
10 miles
Studio Home by Studio Shed offers custom & prefab ADUs across Texas, including San Antonio, Austin, Dallas & Houston. Units range from studios to full living spaces. Permit costs vary: Dallas $3K–$8K, Houston $2.5K–$7.5K.
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North Hill by Toll Brothers
14133 Kearney Loop, Thornton, CO 80602
2.8 miles
Expert ADU contractors handle detached ADUs, garage conversions, granny flats, JADUs & in-law suites. From design and permitting to final inspection, experienced ADU builders ensure code-compliant, high-quality accessory dwelling unit construction.
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Building While Giving
2859 South Locust Street, Denver, CO 80222
17.7 miles
Sustainable Design Build
99 Inca Street, Denver, CO 80223
14.2 miles
Sustainable Design Build is Denver's premier ADU builder and contractor, using design-build for accessory dwelling units, garage conversions, in-law suites, backyard cottages, granny flats, and detached ADUs. Benefits: single contract, faster timelines, cost efficiency, fixed pricing. Experts in local zoning since 2017.
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Prestige Contractors
115 Wilcox Street, Castle Rock, CO 80104
38.2 miles
Prestige Contractors builds ADUs in Castle Rock & Douglas County with 20+ years of experience. Services include detached units, garage conversions, above-garage ADUs & attached additions. Fully permit-managed & code-compliant.
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TinyMod
8150 Gray Fox Dr, Evergreen, CO 80439
28.6 miles
TinyMod (TMOD™) is an offsite development partner offering feasibility analysis, project management, and factory coordination for builders. Services support ADUs, modular communities, BFR, and missing middle housing with up to 60% faster build times.
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Custom ADU Builders LLC
6564 West Atlantic Avenue, Lakewood, CO 80227
19.5 miles
Custom ADU Builders, LLC is Denver's trusted ADU contractor offering detached ADUs, garage conversions, and home remodeling. Serving Aurora, Lakewood & more with transparent pricing and expert permitting support.
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Prospect 30 Eight Construction Inc
2944 Routt Circle, Lakewood, CO 80215
17.7 miles
Prospect 30 Eight Construction proudly offers its high-quality building services to the charming community of Littleton. Known for its unique blend of suburban tranquility and easy access to metropolitan conveniences, Littleton is the ideal setting for a custom home, home addition, and Accessory Dwelling Unit (ADU).
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Koeppen Construction
7845 Lookout Road, Longmont, CO 80503
16 miles
Koeppen Construction builds Accessory Dwelling Units (ADUs) in Longmont, CO, and nearby areas. Services include detached, attached, and garage conversion ADUs for rental, multigenerational living, or guest use. Permitting assistance included.
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Mile High Construction
11012 Newark St., Commerce City, CO 80640
7.7 miles
Mile High Construction is a Denver Metro custom home builder with nearly 30 years of experience. Led by Jordan Barnett, they offer personalized design, sustainable building, and transparent communication, guiding clients from consultation to final walk-through.
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AAA Home Improvements, Inc.
10701 West Morrison Road, Lakewood, CO 80227
20.2 miles
AAA Home Improvements is a Denver ADU contractor building detached ADUs, garage conversions, basement units & in-law suites across the Front Range. They manage design, permitting & construction for homeowners in Denver, Lakewood, Arvada & Littleton.
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Arch Design & Build
9800 Mount Pyramid Court, Englewood, CO 80112
26.8 miles
Arch Design & Build is a licensed Denver remodeling company specializing in ADU construction, garage conversions, kitchen & bathroom remodeling, basement finishing, and home additions. They offer upfront pricing, VR design previews, and a proven step-by-step process.
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Kalin Construction
201 Columbine Street, Denver, CO 80206
13.8 miles
As experienced ADU builders in Denver, Kalin Construction has helped numerous homeowners bring their visions for their homes to life. They'll listen to your wants and needs for the project, then craft an ADU that checks all of your boxes. Whether you're interested in a detached ADU or another type of accessory dwelling unit, they specialize in ADU projects that can provide affordable housing and passive income.
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Prenvalley Builders
5180 Fox Street, Denver, CO 80216
9.8 miles
Prenvalley Builders is Denver's trusted ADU contractor & custom home builder. Specializing in ADUs, renovations, pop-tops & garages across the Front Range, they offer a seamless design-build process with honest pricing & energy-efficient construction.
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What you need to know
Searching for top Attached ADU ADU Contractors in Thornton, Colorado? Our directory highlights trusted local professionals who specialize in designing and building accessory dwelling units (ADUs).
Working with a qualified Attached ADU ADU Contractor in Thornton ensures your ADU project meets local building codes, zoning laws, and permit requirements. Whether you're planning a detached ADU, garage conversion, or backyard cottage, experienced Attached ADU professionals can guide you through every step.
Thornton homeowners are increasingly investing in ADUs to create additional living space, generate rental income, or support multigenerational living. The Attached ADU experts featured here bring local expertise and proven experience to help make your project a success.
Browse our listings to find the best Attached ADU ADU Contractors in Thornton, Colorado, and get started today.