How to Build a Remodeling Budget With a Real Contingency

A realistic remodeling budget starts with the amount you can comfortably spend, sets aside a contingency reserve before anything else, and gives the rest to a ranked list of priorities with honest allowances for finishes you haven't picked yet. For the reserve, plan on 10 to 20% of the project cost: This Old House's contractors call 10% the bare minimum and suggest 15 to 20% for large projects. You'll probably need some of it. In the 2026 Houzz & Home study, 37% of homeowners who renovated in 2025 went over budget, and just 3% finished under.

Start With the Number You Can Live With

Begin with what you can spend without straining your finances, not with what the dream kitchen costs. Add up the cash you're willing to commit and any financing you'd be comfortable repaying, then take the contingency off the top. What's left is your working budget for the project itself.

Next, check that number against real spending. The figures below come from two different kinds of sources, so read them side by side rather than as one range.

Houzz reports what homeowners actually spent, including partly DIY projects, and counts a remodel as major when at least all the kitchen cabinets and appliances are replaced, or a bath's vanity, countertops and toilet. Cost vs. Value prices a fully contracted job with a fixed scope. Treat both as a sanity check, not a quote. Our kitchen remodel cost guide and bathroom remodel cost guide go deeper on ranges.

Rank What Matters Before Anyone Prices It

Every remodel involves trade-offs, so make them at the kitchen table rather than in the middle of demolition. Sort your wish list into three groups:

1. Must-fix: anything failing or unsafe, such as leaks, outdated wiring, a soft subfloor or a bathroom with no working exhaust fan.
2. Must-have: the changes that are the reason you're remodeling, like more counter space, a walk-in shower or storage that fits your cookware.
3. Nice-to-have: upgrades you'd enjoy but could add later or skip, such as a pot filler, heated floors or a second sink.

Price the first two groups fully, and add nice-to-haves only if they still fit with the contingency intact. If bids come back high, you already know what to cut.

Write Allowances You'll Actually Live With

Most contractor bids include allowances: placeholder amounts for items you haven't chosen yet, such as tile, plumbing fixtures, light fixtures or cabinet hardware. If your selections cost more than the allowance, you pay the difference. A bid with thin allowances can look cheaper than a competitor's without actually being cheaper, which is one reason comparing remodeling estimates line by line matters.

The fix is to shop before you sign. Pick the tile and faucet you actually want, then ask the contractor to set allowances from those prices. In the Houzz study, 35% of homeowners who went over budget said they chose more expensive products or materials than planned. Realistic allowances turn that surprise into a decision you make up front.

Size the Contingency Reserve

A contingency covers what nobody can price until the walls and floors are open: water damage, rot, outdated wiring, structural repairs. Whatever you don't spend stays yours. Established sources land in a similar place:

• This Old House: its contractors consider 10% the bare minimum and suggest keeping 15 to 20% in reserve for large-scale projects.
• Fixr: for a bathroom remodel, account for at least a 5% increase over what you expect, to cover surprises like hidden damage.

Those surprises are common. In a 2026 This Old House survey of bathroom renovators, about 24% ran into unexpected water-damage repairs, about 22% faced unplanned structural repairs and about 18% needed mold remediation.

Our recommendation: hold 10% for a cosmetic update in a newer home with a fixed scope, and 15 to 20% for an older house, a full gut, or any project that moves plumbing or opens walls. Release any of it for upgrades only after the walls are closed up.

Choose Financing on Its Terms, Not Its Pitch

In the Houzz study, 84% of homeowners who renovated in 2025 used savings, 34% used credit cards and 13% used a secured home loan. Paying cash costs no interest, though we'd keep an emergency fund intact rather than empty it for a remodel. Here's how the main borrowing options compare, based on the Consumer Financial Protection Bureau's guidance:

HUD's limited 203(k) program also lets buyers and homeowners finance up to $75,000 into their mortgage to repair, improve or upgrade a home. And if a contractor offers financing through a lender they know, the Federal Trade Commission advises never agreeing to it without shopping around and comparing loan terms.

Home-secured borrowing carries a real risk: the CFPB warns that if you fall behind or can't repay on schedule, you could lose your home. Compare total cost, not just the monthly payment.

Keep Scope Creep From Eating the Reserve

Hidden damage isn't the main reason budgets break. Among Houzz respondents who went over budget, 52% said products or services cost more than expected, 35% chose pricier materials than planned, 32% found the project more complex than expected, 31% changed the scope or design and 22% discovered unexpected construction issues. Much of that list is decisions, not bad luck.

A few habits keep it in check:

• Finalize selections, with model numbers, before demolition starts.
• Put every change in a signed change order that states its price and schedule impact before the work happens.
• Keep a running total of the contract price, approved changes and contingency spent.
• When you add an upgrade, name what you'll drop to pay for it.
• Don't pay the full amount up front. The FTC notes that some states limit how much a contractor can ask for as a down payment.

Frequently Asked Questions

Sources

• This Old House – Home Renovation Trends and Tips
• Houzz – 2026 U.S. Houzz & Home Renovation Trends Study
• Zonda / JLC – 2025 Cost vs. Value Report, National Data
• Fixr – How Much Does a Bathroom Remodel Cost?
• Consumer Financial Protection Bureau – What You Should Know About Home Equity Lines of Credit
• Consumer Financial Protection Bureau – What Is a Home Equity Line of Credit (HELOC)?
• HUD – 203(k) Rehabilitation Mortgage Insurance Program Types
• Federal Trade Commission – How To Avoid a Home Improvement Scam