Building Replacement Reserve Calculator

Building replacement reserves fund the eventual full-asset rebuild at end of useful life. The accrued depreciation method computes how much catch-up reserve is owed today and the annual contribution required to be fully funded by replacement-year. Used in institutional underwriting and lender stress tests for older assets approaching their physical decision point.

Building replacement cost (new)

Effective useful life (yrs)

Current building age (yrs)

Reserve interest %

Accrued depreciation

$4,320,000

Annual reserve contribution

$82,281

Remaining useful life (yrs)

How the math works

Building replacement reserve sizes the catch-up funding to keep pace with depreciation. Annual contribution = accrued depreciation ÷ remaining-life annuity factor — funded so the reserve grows to full replacement cost by year-of-replacement.

For institutional underwriting, this is the deferred maintenance / replacement burden buyers should absorb in their pricing model.

How to Use

Enter building replacement cost (new construction equivalent).
Enter effective useful life (typically 50-75 years for institutional assets).
Enter current building age and reserve interest rate.
Read accrued depreciation, annual contribution, and remaining useful life.

Frequently Asked Questions

Useful life benchmarks?

Wood frame multifamily 40-50 years; steel/concrete office 50-75 years; industrial 30-50 years; pre-engineered metal 25-40 years. Add 50% if maintained well; subtract 30% if deferred.