ADU planning tools
Pencil out your ADU before you call a builder.
Four free tools that take you from "is this even possible?" to "here are my real numbers." Each one runs in your browser, takes under five minutes, and emails you the results so you have them when you're ready to talk to a contractor or lender.
ADU cost calculator
A defensible low/mid/high estimate calibrated to 2025–2026 builder data by state, ADU type, size, and finish level.
Estimate costROI calculator
Project cash flow, payback period, and property-value uplift from rental or family use of your ADU.
See the mathLoan calculator
Compare HELOC, cash-out refi, construction loans, and renovation loans side by side with real rate ranges.
Compare loansFeasibility check
Seven questions to find out whether you can actually build an ADU on your lot under current state and city rules.
Check feasibilityHow to use these tools together
- 1. Start with feasibility. If your lot doesn't qualify, the other tools don't matter. The 90-second feasibility check covers setbacks, height limits, lot coverage, and the state-specific rules that disqualify the most projects.
- 2. Get a cost range. The cost calculator gives you a low/mid/high estimate tied to your state, ADU type, square footage, and finish level — so you walk into builder conversations with realistic numbers.
- 3. Stress-test the financing. The loan calculator compares HELOC, cash-out refi, construction loans, and renovation loans against your actual rate and equity position. Most homeowners are surprised by which one wins.
- 4. Confirm the ROI. The ROI calculator combines the cost and financing inputs with a local rent estimate to show cash flow, payback period, and property value uplift over time.
Get the full Homeowner's Playbook
A 28-page PDF covering process, costs, permits, financing, and the five most common ways homeowners overspend on an ADU. Free.