ADU Calculator
Enter your bids, financing and expected rent to see what an accessory dwelling unit costs each month, how long it takes to pay back and what it yields on what you spend.
Confirm these locally before counting on rent
Tick each once confirmed for this property (0 of 6).
1. What it costs
From your contractor. Reaixo does not estimate ADU prices.
Design, permits, impact and utility-connection fees, site work.
2. Financing
0 if paying cash.
3. Rent and running costs
From comparable rentals; 0 for family use.
Ask your assessor how the ADU will be assessed.
0 if you manage it yourself.
Leave at 0 if you do not have an estimate.
Results
Enter your construction bid to see results.
How the numbers work
- Cash flow = rent after vacancy − management, added tax and insurance, maintenance and utilities − the loan payment. It uses the same engine as the rental cash flow calculator.
- Only costs the ADU adds are counted; the main house's mortgage and bills exist either way.
- Figures are pre-tax. Rent increases, depreciation and income tax on the rent are not modelled.
- Every cost, the rent and the value added come from you. Get written bids and check rent against comparable listings.
Considering an ADU on a specific property?
A Remodeling Potential report looks at the property, its value and its improvement options. It does not confirm zoning or permits - check those with your municipality.
See the Remodeling Potential reportADU questions
How much does an ADU cost to build?
It varies widely with size, whether it is detached, attached or a conversion, site work, utility connections and local fees. This calculator does not supply prices: enter your contractor's bid and the soft costs your municipality and designer quote.
Can I rent out an ADU?
Only where local rules allow it. Some places require the owner to live on the property, set minimum lease lengths or ban short-term rentals, and many require a rental licence. Confirm before you build.
Does an ADU add value to my home?
Often, but how much depends on the local market and whether the unit is legal and permitted. Ask an appraiser or agent for an estimate and enter it as value added; leave it at zero if you do not have one.
What is yield on cost?
The ADU's net operating income (rent after vacancy and operating costs, before the loan) divided by everything it cost to build. It lets you compare the project with other uses of the money, regardless of financing.
Educational Use Only: Reaixo provides estimates for informational and educational purposes. Reaixo is not an appraiser, contractor, real-estate broker, financial advisor, tax advisor, or investment advisor. Project costs, property-value changes, buyer preferences and cost recovery vary significantly by property, location, project scope, workmanship and market conditions. Obtain project-specific estimates and professional advice before making renovation or financial decisions.
Related Tools
Kitchen Remodel ROI
Estimate cost recovery for a kitchen renovation — cosmetic refresh through full remodel.
Calculate Kitchen ROI →Bathroom Remodel ROI
Analyze bathroom improvements — cosmetic refresh through major remodel.
Calculate Bathroom ROI →Deck ROI
Analyze new deck, replacement or expansion projects.
Calculate Deck ROI →Basement ROI
Estimate the value added and cost recovery from finishing or remodeling a basement.
Calculate Basement ROI →Home Addition ROI
Analyze the cost and value impact of adding square footage to your home.
Calculate Addition ROI →Roof Replacement
Replace now or keep repairing? Compare your quotes in today's dollars.
Compare Roof Options →HVAC Replacement
Repair the old system or replace it? Includes energy savings and resale value.
Compare HVAC Options →Home Improvement ROI
Compare any home improvement project — cost, value added and cost recovery.
Compare Any Project →