How to Estimate Rehab Costs: A Line-Item Guide for Fix & Flip Investors

Most flips don't fail on the purchase price. They fail on the rehab number.

An investor tours a property, eyeballs the kitchen, says "call it forty grand," and writes an offer. Four months later the budget is at sixty-eight, the holding costs have run two months long, and the profit that looked like $55,000 on a napkin has become $9,000 — or a loss. The purchase price was fine. The renovation estimate was fiction.

Learning how to estimate rehab costs accurately is the single highest-leverage skill in fix & flip investing, because that one number flows into everything downstream: your maximum allowable offer, your after-repair value assumptions, your timeline, and the size of the loan a lender will write. This guide covers the two methods professionals use, current 2026 line-item pricing, and the mistakes that turn a good deal into a bad one.

The Two Ways to Estimate a Rehab

There are only two legitimate approaches, and serious investors use both — one to screen, one to commit.

Method 1: Per-Square-Foot Screening

The fast method multiplies the property's square footage by a cost-per-square-foot figure matched to the scope of work. It takes ninety seconds and is accurate enough to decide whether a property is worth a second look.

Scope tiers and their 2026 investor-grade ranges:

On a 1,600 sq ft house needing a moderate rehab, that's roughly $48,000–$64,000. Good enough to know whether to keep reading the listing.

Two adjustments matter. First, market: labor-constrained metros like Austin, Phoenix, and Denver commonly run 20–40% above the national midpoint, while Midwest and Southeast markets run below it. The same scope that costs $35/sq ft in Indianapolis can cost $55/sq ft in a hot Sun Belt market. Second, grade: these are investor-grade numbers using durable, mid-tier materials — not the retail homeowner remodel figures you'll find quoted at $25,000–$60,000 for a kitchen. Investors buying contractor-grade cabinets and quartz remnants routinely deliver a sellable kitchen for a fraction of that.

Method 2: The Line-Item Scope of Work

Before you commit capital, per-square-foot is not enough. You build a scope of work — a room-by-room, system-by-system list of every item to be replaced or repaired, each with a quantity and a price.

Walk the property with a checklist and price these categories:

Systems and structure — foundation, framing, roof, electrical panel and wiring, plumbing supply and drain lines, HVAC, water heater. These are the budget killers because they're expensive, non-negotiable, and largely invisible from the curb.

Exterior — siding, windows, doors, gutters, driveway, fencing, landscaping, paint.

Interior — flooring, drywall, interior paint, trim and doors, kitchen cabinets and counters, appliances, bathroom fixtures and tile, lighting.

Soft costs — permits, dumpsters, utilities during construction, cleaning, staging. These typically add 5–8% and are the line items investors most often forget entirely.

2026 Line-Item Benchmarks

Use these as sanity checks against contractor bids, not as substitutes for them. Prices reflect investor-grade work on a typical single-family flip.

If a contractor's bid comes in 40% under these ranges, that's not a bargain — it's a bid that will be revised mid-project.

Always Add a Contingency

Every professional rehab budget carries a contingency line. Budget 10–15% on cosmetic and light rehabs, and 15–20% on heavy and gut jobs, where opening walls reliably reveals problems no walkthrough could have found.

A contingency is not padding. It is the acknowledgment that on a 1950s property you will find aluminum wiring, cast iron drain lines, or a subfloor that has to come out. If you finish under budget, the contingency becomes profit. If you skip it, the overrun comes out of your pocket at the worst possible moment.

How Your Rehab Estimate Drives Your Loan

This is where estimating stops being an exercise and starts being money.

Fix & flip lenders don't finance the purchase price alone — they finance a percentage of total project cost, which is purchase plus rehab. That's the loan-to-cost (LTC) figure, and it's why your rehab number directly determines how much capital you have to bring.

Consider a $260,000 purchase with a $70,000 rehab. Total cost is $330,000. At 90% LTC, the loan covers $297,000 and you bring $33,000 plus closing costs. Understate the rehab at $45,000, and the lender sizes the loan to $274,500 — leaving you to fund the missing $25,000 of real construction cost entirely out of pocket, mid-project, when your cash is already committed.

There's a second constraint. Lenders also cap the loan against ARV, typically at 70–75%. If your ARV is $420,000, a 70% cap puts the ceiling at $294,000 — and the binding constraint becomes whichever number is lower. Both calculations depend on estimates you produced. Getting them right isn't paperwork; it's the difference between a funded project and a stalled one.

Rehab dollars are also released through a draw schedule rather than at closing, reimbursed as work is completed and inspected. That means your line-item scope of work isn't just an internal document — it becomes the framework the lender uses to release funds. A vague budget produces slow draws. A detailed one produces fast ones.

Underwriting reviews your rehab budget as part of standard fix & flip loan requirements, which is another reason the line-item version is worth building before you apply. Get your project reviewed with the budget already in hand and the process moves considerably faster.

Four Mistakes That Blow Up Budgets

Estimating from photos. Listing photos are shot to hide problems. Nobody photographs the panel box, the crawlspace, or the water stain behind the dryer. Walk the property, or send someone who will.

Pricing the visible, ignoring the mechanical. New quartz counters photograph well. A failing sewer lateral does not — and costs more. Price systems first, finishes last.

Forgetting holding costs. Rehab budgets cover construction. They don't cover the loan interest, insurance, taxes, and utilities that accrue every month the project runs. On a $300,000 loan at 9%, that's roughly $2,250 a month in interest alone. A two-month overrun is a $4,500 line item that never appeared in the spreadsheet.

Trusting one bid. Get three. The spread between contractor bids on identical scope routinely exceeds 30%, and the middle bid is usually the honest one.

Turn a Solid Budget Into a Funded Deal

A rehab estimate you can defend is what separates investors who get funded from investors who get declined. Bring us a real scope of work, and we'll move on it.

Funded Capital is a Miami-based private lender financing fix & flip and ground-up projects across 45 states. Our Fix & Flip loans start at 8.75% with up to 90% LTC, including rehab funds released on a structured draw schedule. New construction financing starts at 8.75% with up to 85–90% of cost, and when you're ready to hold the property, DSCR loans start at 6.75% with up to 80% LTV — with no income verification on most programs.

You'll get a term sheet in about 2 hours on average and can close in 5–10 business days. Run your numbers on our deal calculator, see how the process works, and when the budget pencils out, apply now.

Frequently Asked Questions

How much does it cost to rehab a house per square foot? Investor-grade rehabs generally run $10–$20 per square foot for cosmetic work, $30–$40 for a moderate rehab with a new kitchen and updated baths, $40–$60 for heavy rehabs, and $60–$100+ for a full gut to the studs. High-labor-cost metros run 20–40% above these midpoints.

What contingency should I include in a rehab budget? Carry 10–15% on cosmetic and light rehabs and 15–20% on heavy or gut projects. Older properties and any job that opens walls warrant the higher end, since hidden electrical, plumbing, and structural issues are common rather than exceptional.

Do lenders finance rehab costs? Yes. Fix & flip lenders finance a percentage of total project cost — purchase plus rehab — with the rehab portion held back and released through a draw schedule as work is completed and inspected. Funded Capital finances up to 90% LTC on fix & flip loans.

How accurate does my rehab estimate need to be for a loan? Accurate enough to survive underwriting review. Lenders size the loan off your total cost figure, so an understated budget produces an undersized loan and a funding gap you cover personally. A line-item scope of work with contractor bids is the standard.

Should I estimate rehab costs before or after making an offer? Screen with a per-square-foot estimate before offering so you can set your maximum offer under the 70% rule. Then build the detailed line-item scope during your inspection period, while you can still renegotiate or walk if the real number comes in materially higher.