Homes with mother in law suites — Longmont, CO
Last updated: September 24, 2026
What affects the price
Building an ADU is a custom project, so costs vary based on your specific choices. Site conditions are the biggest factor; if your land requires significant grading, utility extensions, or foundation work, those expenses add up quickly. Choosing high-end finishes, custom cabinetry, or complex roof lines will also push the budget higher compared to a standard design. Prefabricated units often offer predictable costs, while custom site-built structures allow for more flexibility but can be harder to estimate upfront. Exact pricing confirmed free on the call.
About this service
These homes include a dedicated living area for family members, often equipped with a private bathroom or small kitchenette. You need this if you want to keep family close while respecting everyone’s need for personal space. The cost of adding this to your home is typically driven by your plumbing needs, electrical requirements, and the scale of the interior renovation. Exact pricing confirmed free on the call.
Frequently asked in Longmont
What are the benefits of accessory dwelling unit homes in Longmont?
What is the process for an ADU permit in Longmont?
How much does it cost to build an accessory dwelling unit in Longmont?
What does 'accessory dwelling unit' mean in Longmont?
What are the advantages of a detached accessory dwelling unit in Longmont?
How do I get an ADU quote for construction in Longmont?
Also serving nearby: Boulder · Thornton · Westminster · Arvada · Greeley
More on this: HUD ADU resources — ADU policy and financing research.
Service area details
Serving all of Longmont — population 98,630; about 3,396 residents per square mile across 29.0 sq mi. ZIP codes covered include 80501, 80502, 80503, 80504.
Neighborhoods served in Longmont: Mountain View, Old Town, Prospect, The Lakes, Westview — and every surrounding area.
Areas we serve
Browse by state, then city.