Property value + ADU cost calculator

Calculate the ADU cost, value spread, and rental-income path.

Enter an address or city, choose the 500 sf one-bedroom or approx. 1,000 sf three-bedroom path, then compare the $170/sf base unit against editable market value, rent, delivery, crane, site-work, utility, permit, and tax assumptions.

How it works

Address first, editable comps second, exact quotes later.

The calculator follows the way buyers already think: what does the ADU cost, what might it add to property value, what could it rent for, and which line items still need a real supplier or site quote. The address field is used for context only; buyers should replace the market assumptions with their own appraisal, Redfin/Zillow comp, rent comp, or property-manager input.

product path site conditions permit boundary prefab ADU cost

1. Property value inputs

U.S. project address or city Local finished value, $ per sf Estimated monthly rent Sales tax / local tax allowance

Use the U.S. address or delivery city to choose a local comp and planning region, then replace the defaults with your own market data. This page does not scrape Zillow, Redfin, MLS, or rental platforms.

2. Project profile

Model path Target square feet Project delivery region Finish level

3. Site conditions

Site complexity Utility distance, feet Utility condition Delivery and setting access

4. Editable assumptions

These planning defaults are editable. Replace them when you have a supplier quote, engineer number, city fee estimate, or utility bid.

Factory/build package, $ per sf Delivery + setting override Foundation/site override Utilities override Permits/soft-cost override Contingency percent 12%

Standard fields

What the calculator shows.

The calculator is built around the questions buyers already ask: enter property context, choose size, region, finish level, site condition, utility distance, and access difficulty, then inspect cost, value, and rental-income outputs together.

Square-foot driverUses a visible editable dollar-per-square-foot allowance instead of hiding the unit math.

Site-work driverFoundation, utility distance, and delivery access are separate because they are common ADU budget swing factors.

Value outputCompares the project estimate against editable local value-per-square-foot and rental assumptions.

Product boundaryKeeps the factory/build package separate from local permits, utilities, foundation, and setting.