ADU financial decision tool
More than a rent number. Put construction, financing, operating costs, and taxes in the same conversation—before you commit.
Compare the same property with and without an ADU, then test the assumptions behind the result.
Same home. Two scenarios.
Modeled after-tax cash flow
A smaller monthly outflow—not $550 of total property income.
01 / Your starting point
Same project. Different questions. Choose a perspective to explore the comparison.
Homeowner perspective: Start with the change in monthly cash flow, then test the construction cost and additional cash required.
02 / Look past the rent
An extra $2,500 in monthly rent is not an extra $2,500 in your pocket. Follow the bridge from income to impact.
Illustrative comparison
This is an educational illustration, not app-generated output or a real property analysis.
Simplified synthetic assumptions in USD. Financing, expenses, and tax effects are invented for this example; they do not describe a typical ADU. Construction cash and any eventual sale are outside this monthly illustration. This is not a payoff or investment-return calculation.
The comparison puts additional peak cash required and incremental modeled cash gain alongside monthly cash flow, with With ADU / Without ADU IRR for investment decisions.
Modeled results depend on your assumptions and are not a payment quote, appraisal, tax opinion, or contractor bid.
03 / A better way to think it through
The workflow keeps the assumptions close to the answer.
Start with your goal, the property, and the numbers you know. Identify what you still need from your builder, lender, or adviser.
Bring a construction estimate. Test rent, financing, expenses, taxes, and timing—not just the best-case scenario.
Look at the same property with and without the ADU. Test a higher cost, lower rent, or construction delay before relying on the result.
Construction planning
The construction-estimate workflow helps organize a low, likely, and high planning range. It is a starting point for questions—not a contractor quote.
Review the estimate sources, usage limits, and data disclosures in the app. You can explore this page without entering any project or address information.
What an estimate can—and cannot—tell youMake uncertainty visible.
For professionals
Builders, designers, lenders, and real-estate professionals bring different expertise. A shared financial comparison gives the conversation a common starting point.
Use your own project assumptions to discuss the tradeoffs. Save revisions and prepare client-ready reports, with branding on eligible plans. Check plan eligibility and limits before subscribing.
Discuss professional useWhy Grant built ADUroi
A real project. Substantial cash at stake. Contractor quotes that were hard to compare.
When Grant Olsen bought an investment property in Southern California, he wanted to understand whether an ADU could help offset the costs of owning it. He built a financial calculator before committing to a garage conversion.
That experience is still the point: make the assumptions visible, understand the tradeoffs, and decide with more context.
Read the original founder storyOriginally published in 2020. Historical financing and legal statements in that story are not current guidance.
Pricing / Monthly plans
Choose a monthly plan for your own project or client work. Please confirm the price and terms in the app before subscribing.
Personal ADU Edition
For homeowners and investors thinking through their own ADU decision.
Start an evaluationProfessional
Considering ADUroi for client work? Confirm the current scope and terms with us.
Discuss your needsEnterprise
For a conversation about broader organizational use and requirements.
Talk to ADUroiReview trial terms, plan limits, and eligibility for PDF reports, saved revisions, branding, and construction-estimate allowances before subscribing. Features and allowances depend on your plan.
Before you get started
Financial planning works better when you know what the model can—and cannot—tell you.
Ask us a questionADUroi models ADU cash flow and financial returns, including mortgage payments, IRR, cap rate, and maximum cash used. Compare monthly impact and the same property with and without an ADU.
No. This page's sample is synthetic. The construction-range feature provides a planning estimate, not a bid, site inspection, or commitment from a contractor. Confirm scope, feasibility, and pricing with local professionals.
Yes. Enter your own construction-cost assumption rather than use a generated estimate. Check what your builder's estimate includes and account for exclusions separately.
Rent alone does not show the ADU's financial effect. Comparing the same property in two scenarios helps separate the additional income from the additional costs, financing, taxes, and cash required.
No. ADUroi does not replace a tax adviser, lender, appraiser, contractor, attorney, or local planning department. All results depend on assumptions. Verify zoning, permits, taxes, financing, and project costs independently.
No. This marketing page collects no project information and its sample works without an address. The app is a separate service; review its data requirements and privacy policies before entering information.
Professional and Enterprise plans support client work. Contact ADUroi to confirm client-use terms, limits, and eligibility for branded reports before subscribing.
Yes. Save named revisions as you change assumptions and restore earlier versions to compare alternatives. Check your plan's limits before relying on it for ongoing client work.
Your next step
Start an evaluation, or talk to ADUroi about the decision in front of you.
Use your own assumptions. Verify the result before committing.