ADU cost in Denver (2026): real ranges, then your number

Published ranges

What a detached ADU costs in Denver, by tier

Typical Denver ranges — your estimate narrows this to one. The same three bands appear on the Instant Estimate's tier cards; nothing here is rounded differently or typed by hand.

Why the range is a range

What moves the number

These are estimates, not a quote. Each range is a published tier band from the same estimating engine behind our Instant Estimate; the wizard narrows it to one number for your lot and finish level, and the build itself is quoted afterward as a fixed-price proposal.

Permits

Who permits an ADU in Denver

City and County of Denver — Community Planning and Development. Building permits in Denver are issued by Community Planning and Development, and contractor licensing here is municipal — a Denver-licensed contractor pulls Denver permits. We handle permit applications and inspections as part of every project.

FAQ

Cost, timeline, permits

Are the ranges on this page a quote?

These are estimates, not a quote. Each range is a published tier band from the same estimating engine behind our Instant Estimate; the wizard narrows it to one number for your lot and finish level, and the build itself is quoted afterward as a fixed-price proposal.

What does an ADU cost?

Getting a real answer costs less than most people expect: an ADU feasibility consultation is $350, and the full ADU feasibility package — zoning check, site analysis, and concept direction — is $950, both listed at fixed prices on our booking page. Construction cost depends on the path: garage and basement conversions reuse existing structure, while a detached backyard cottage is new construction from the foundation up. After feasibility we quote the build itself as a fixed-price proposal, so you know the number before work starts.

How long does an ADU project take?

Three phases run in sequence: design (site measure, concept, construction documents), permitting (zoning and building review, which move on the municipality’s calendar), then construction. Conversions generally move faster than detached new builds because the shell and foundation already exist. We lay out the phase-by-phase schedule in your proposal, and you track progress on our operations platform once work starts.

What is the ADU permit process?

Two municipal reviews run in order: a zoning review confirming the unit fits your district’s standards, then a building permit review of the construction documents, with inspections during the build and a certificate of occupancy at the end. Colorado HB 24-1152 now requires most Front Range municipalities to allow ADUs on single-unit lots, and we confirm how your city implements it as the first step of feasibility.