ADU Rental Income in Denver: What Homeowners Can Realistically Expect
Most Denver homeowners weighing whether to build an ADU run the numbers at some point. The construction cost is large; the rental income sounds appealing. The honest math is more interesting than either extreme, because it depends on neighborhood, unit size, finish level, operating costs, and how long you plan to hold the property. A one-bedroom ADU in a strong rental neighborhood can pay back the construction cost in 10 to 14 years and produce meaningful cash flow after that. The same ADU in a weaker rental neighborhood takes 18 to 25 years to pay back, which is a different decision entirely.
This article walks through the income side of the ADU equation for Denver: realistic rent ranges by unit size and neighborhood, the operating costs that reduce net income, the tax considerations homeowners often miss, and the payback math that matters. By the end you should be able to model your own ADU rental income with honest numbers.
The income picture at a glance
Studio ADU: $1,200 to $1,700 per month gross rent in most Denver neighborhoods.
One-bedroom ADU: $1,500 to $2,200 per month gross rent.
Two-bedroom ADU: $2,200 to $3,200 per month gross rent.
Operating cost rule: Plan to lose 20 to 30 percent of gross rent to operating costs (insurance, maintenance, vacancy, property management if used).
Payback math: Most Denver ADUs reach construction cost payback in 10 to 18 years on long-term rental.
What rent looks like by neighborhood
Denver rents vary substantially by neighborhood. Highland, Wash Park, LoHi, Sloan's Lake, and Berkeley command the highest one-bedroom ADU rents, generally $1,900 to $2,400 per month for a thoughtfully designed unit. Park Hill, City Park, Stapleton, and Sunnyside fall in the middle, generally $1,600 to $2,100 per month. Newer or further-out neighborhoods (Green Valley Ranch, Montbello, parts of Aurora) generally rent $1,300 to $1,700 per month for a comparable unit.
The neighborhood premium matters more than the finish level, within reason. A one-bedroom ADU with mid-grade finishes in Highland rents for more than a one-bedroom ADU with luxury finishes in a weaker rental market. Tenants pay for location first and finishes second.
Short-term rental (Airbnb-style) income can be higher per month than long-term rental, but only where Denver's short-term rental rules allow. Short-term rentals in Denver generally require an owner-occupancy requirement (the primary home must be the host's primary residence), which means the main house qualifies, not the ADU. Confirm short-term rules with the City of Denver before underwriting a short-term rental income assumption.
Operating costs that reduce net income
Gross rent is not net income. Several recurring costs reduce what the ADU actually contributes to your finances:
Property tax. Adding an ADU increases the assessed value of the property, which increases the annual property tax. The Denver County assessor adjusts the assessment on the next reassessment cycle after the ADU is finished. The increase varies but typically runs $1,200 to $2,500 per year for a one-bedroom ADU on a typical Denver lot.
Insurance. Adding a rental unit to your homeowner's policy increases the premium, often by 15 to 30 percent. Some carriers require a separate landlord policy for the rental unit, which can run $800 to $1,500 per year on top of the existing policy.
Maintenance and repairs. A typical rental property loses 8 to 15 percent of gross rent to maintenance over time, including unit turnovers (cleaning, painting, minor repairs between tenants), system replacements (water heater, HVAC), and unexpected issues. ADUs tend to fall at the lower end of this range early in their life and trend toward the higher end as they age.
Vacancy. Even a desirable Denver ADU will be vacant occasionally between tenants. Plan to lose 4 to 8 percent of gross rent to vacancy over a multi-year period.
Property management. If you self-manage, this cost is zero (plus your time). If you hire a property manager, plan to lose 8 to 10 percent of gross rent to management fees.
Combined, the operating cost stack typically runs 20 to 30 percent of gross rent for an owner-managed ADU, 30 to 40 percent if professionally managed. That converts $2,000 per month gross to roughly $1,400 to $1,600 per month net for a self-managed Denver one-bedroom.
The payback math
The honest way to look at ADU ROI is to compare net annual rental income against construction cost. A $325,000 one-bedroom ADU in a mid-tier Denver neighborhood with $1,900 monthly gross rent generates roughly $22,800 in gross annual rent. After 25 percent operating costs, net annual income is roughly $17,100. The simple payback period is 19 years (325,000 divided by 17,100).
Two things adjust that number meaningfully. First, rents rise over time, usually at or above inflation. If rents grow at 3 percent annually, the same ADU returns substantially more in years 10 and 20 than in year 1, which compresses the actual payback. Second, the ADU adds to the home's value at sale time, often by 50 to 80 percent of the construction cost on a well-built ADU in a strong neighborhood. Selling the home recoups much of the remaining construction cost even if the rental income has not paid it back.
The realistic payback for most Denver ADUs is 10 to 18 years on long-term rental, with neighborhood and finish level driving the spread. Add multigenerational use (housing a family member rent-free) and the conversation shifts from rental ROI to family value, which is harder to model but often more important.
Tax considerations
Rental income from an ADU is reportable income and taxable at your federal and state tax rates. Several deductions offset that: mortgage interest on the portion of the loan attributable to the ADU, property tax on the ADU portion, insurance, maintenance, depreciation (the ADU's value depreciated over 27.5 years), and a share of utilities if you pay them.
The depreciation deduction is particularly meaningful. A $325,000 ADU depreciates at roughly $11,800 per year for tax purposes, which can offset most or all of the rental income from a tax perspective, depending on your other income. Talk to a CPA before signing a contract; the tax treatment of the ADU can change the effective return meaningfully.
If you sell the home with the ADU later, the depreciation is recaptured at sale (paid back to the IRS at a 25 percent recapture rate). This is normal for any rental property and should be modeled into the long-term decision.
Common mistakes homeowners make
The first mistake is using gross rent in the ROI math. Twenty to thirty percent of gross rent disappears to operating costs; modeling gross as net overstates the return by years.
The second mistake is underestimating vacancy in early years. The first tenant may take 30 to 60 days to find after construction ends, and there is typically a 2 to 4 week gap between tenants on each turnover. Plan for that explicitly.
The third mistake is over-finishing the unit. A mid-grade finish level rents for nearly the same amount as a luxury finish level in most Denver neighborhoods, but costs $20,000 to $50,000 less to build. Spend money on layout and storage; do not over-spend on appliances and fixtures.
The fourth mistake is not understanding the financing structure. Most ADU construction is financed through a HELOC, a construction loan, or a cash-out refinance. Each has different interest costs and different effects on the long-term return. ADU financing options covers the lending structures and trade-offs.
What this means for your decision
Run the math with honest numbers before committing. Net income (not gross), realistic vacancy (not zero), and operating cost (not optimistic) are the starting points. If the payback period under conservative assumptions is 12 to 15 years and you plan to hold the home 15 or more years, the ADU is usually a good financial decision. If the payback period exceeds 20 years and you are less certain about long-term ownership, the analysis gets tighter.
If you are still scoping the project, the income picture connects to the floor plan choice (larger units rent for more but cost more to build) and the construction cost (which sets the payback target).
If you are weighing this against alternatives, ADU vs home addition covers the trade-off with the other common Denver expansion option.
Working with a Denver ADU contractor
A good ADU contractor should understand the rental income side of the project as well as the construction side. They will model the expected rent for your neighborhood, recommend finish levels that fit the rental market, and explain trade-offs between cost and rentability. They will also coordinate with your CPA on the tax structuring if helpful. DDB's ADU service overview describes how we approach the financial side of an ADU project alongside the build.