Estimated Value Added by ADU
?
Your home’s price per sq ft ($X) multiplied by your planned ADU size. This estimates what the ADU space would be worth based on your property’s actual economics.
$250,000
Based on $417/sq ft × 600 sq ft
Do-Not-Exceed Budget
?
Value Added minus a 20% safety margin for appraisal variances and market downturns. Staying under this number means your ADU should add value even in a down market.
$200,000
Value added minus 20% safety margin
Budget vs. Do-Not-Exceed
$0
Right at the ceiling
Annual Rental Income (Net)
$21,120
After 20% vacancy + expenses
Where Does Your Budget Fall?
$0
What Happens at Different Spend Levels
ADU Cost
Value Added
Net Gain / Loss
Break-Even (Rent)
Verdict
How Financing Affects Your Break-Even
If you finance $200,000, here’s how different interest rates and loan terms impact your monthly payment and time to recoup through rent.
