What a Backyard Cottage Is
A backyard cottage is a separate dwelling unit on the same lot as the primary home. It usually includes its own entrance, kitchen, bathroom, sleeping area, utilities, and address or unit identification depending on the jurisdiction. Homeowners use detached ADUs for rental income, multigenerational housing, aging parents, adult children, or flexible guest space.
Best-Fit Properties
Detached ADUs tend to work best on lots with usable rear-yard area, clear side-yard access, reasonable setbacks, and utility routes that do not require unusually long trenching. Corner lots, alley-access lots, and deeper suburban lots often have an easier path. Sloped lots can still work, but grading, drainage, stairs, and retaining walls can move the budget quickly.
Typical Cost Range
Most detached ADUs in the Denver metro area fall between $200,000 and $400,000. The lower end usually means a compact studio or one-bedroom plan with standard finishes and simple utility access. The upper end usually means a larger custom unit, premium finishes, more complicated site work, or utility upgrades.
Key Questions Before You Build
Before you engage a builder, confirm whether your lot can meet local setback, lot coverage, height, utility, fire access, and parking rules. You should also understand HOA review, drainage constraints, sewer capacity, and whether your planned use is long-term rental, family housing, or occasional guest space.
How Colorado ADU Pro Helps
We are not the builder. We help you organize the early decision: what type of ADU fits, what the likely budget band looks like, what local rules may matter, and what questions to ask when you speak with architects, lenders, or builders.
Start with the ADU quiz. It captures your property type, goals, budget range, and readiness questions so the next step is focused. Take the ADU readiness quiz.