Faro Labs / Tools / Rehab budget calculator
Rehab budget calculator
A renovation budget built from line items you can defend, with the one number every first-timer skips: contingency. Itemize by category and get your total cost and cost per square foot.
A 15% contingency adds $10,230 on top of $68,200 in line items. On an older property, that cushion is the difference between a surprise and a loss.
How to build a rehab budget that holds
cost per sq ft = total budget ÷ square footage
A defensible rehab budget is built from the bottom up, real line items for real scopes of work, not top-down from a cost-per-square-foot rule. Cost per square foot is a sanity check you apply after, to catch a budget that's wildly off, not a way to generate the number. The categories here mirror how a general contractor bids: structure and envelope first, then the mechanical systems, then the interior finishes buyers actually see.
Why the contingency is non-negotiable
The line items cover what you can see. The contingency covers what you can't: the wiring behind the wall, the water damage under the vanity, the code upgrade a permit triggers. Fifteen percent is a reasonable floor; on a pre-1970 home, twenty or more is prudent. The renovations that blow up a deal almost never do it on the visible scope. They do it in the surprises, and the contingency is the only line protecting against them.
Where the money concentrates
Kitchens, bathrooms, and the three big systems, electrical, plumbing, HVAC, dominate most budgets. Finishes are visible and easy to estimate; the systems are hidden, expensive, and the ones an inspector or a permit can force you to touch whether you planned to or not.
Rehab questions
How much contingency should a rehab budget include?
At least 10 to 20 percent on top of your line items, and more on older homes where you can't see behind the walls. Renovations reliably uncover surprises, old wiring, hidden water damage, code upgrades, and the contingency is what keeps those from turning a profitable project into a loss.
What's a rough cost per square foot for a rehab?
It ranges enormously by scope and market: a cosmetic refresh might be $15 to $30 per square foot, a full gut renovation $75 to $150 or more. Use cost per square foot to sanity-check a budget you built from line items, not to build the budget itself.
What are the most underestimated rehab line items?
The systems you can't see and the ones code forces you to touch: electrical, plumbing, and HVAC. A cosmetic budget balloons the moment an inspector requires a panel upgrade or a permit triggers bringing something up to current code, which is exactly why those categories get their own lines here.
Every calculator
Rehabbing to rent?
Faro's BRRRR analysis folds your rehab budget into the refinance and the long-term cash flow: paste a listing to see it.
Estimates for analysis and educational use only: not financial, investment, tax, or legal advice. Verify every number independently before making a purchase decision.