Construction Contingency: How Much to Carry and How to Use It
A construction contingency is money set aside in the budget for costs that can’t be identified or priced when the project starts. On new homes it’s commonly carried as a percentage of construction cost, often somewhere around 5% to 10%, with more for remodels, difficult sites, or incomplete plans. How much you carry matters less than having clear rules for who owns it, what it can be spent on, and who approves spending it.
Every house has surprises in it. The contingency is how you admit that in advance. Builders who skip it don’t avoid the surprises. They just pay for them out of profit.
What does construction contingency mean?
Construction contingency means a reserve for the unknown. It’s a line in the budget with no scope attached to it yet, waiting for something to happen that nobody could have priced.
It helps to be clear about what it isn’t:
It isn’t profit. If you’re counting on unspent contingency to make your margin, you’ve underpriced the job.
It isn’t an allowance. Allowances cover known items with unknown prices. I compare the two in allowance vs. contingency.
It isn’t an upgrade fund. A client wanting nicer tile is a selection decision, handled with a change order.
It isn’t a fix for a bad estimate. Contingency covers what you couldn’t know. It doesn’t cover what you didn’t bother to find out.
What is a typical construction contingency percentage?
A typical contingency for construction projects in residential work commonly falls somewhere around 5% to 10% of construction cost for a new home. That range varies with the market, the builder, and the project, and plenty of jobs justify more or less.
The right percentage depends on how much you don’t know:
Completeness of the plans and specs. Finished drawings and a full specification support a smaller number. A sketch and a handshake need a larger one.
The site. A flat lot in a subdivision you’ve built in before is low risk. A sloped lot with unknown soil is not.
New build or remodel. Remodels hide their problems behind drywall, so they commonly carry more.
How firm your pricing is. Signed trade bids are solid. Estimates from last year’s job are not.
The length of the job. More months means more exposure to price changes.
The calculation is simple. Say your hard construction cost is $800,000 and you decide 6% fits the risk. Your construction contingency is $48,000. As a second check, list the specific things that worry you on this job, put a rough dollar figure on each, and see whether the total is in the same neighborhood. If your worry list adds up to $90,000, 6% isn’t your number.
What are some construction contingency examples?
Good construction contingency examples all share one trait: nobody chose them.
Rock or bad soil discovered during excavation, requiring extra equipment time or a revised foundation.
A utility connection that turns out to be longer, deeper, or more expensive than the provider first indicated.
A material price increase between the day you budgeted lumber and the day you ordered it.
A missed detail in the drawings, like flashing or blocking that has to be built but wasn’t priced by anyone.
An inspector’s requirement that goes beyond what was on the approved plans.
Weather damage, like regrading after a storm or replacing material that got soaked.
A trade that walks off and has to be replaced at a higher price.
Examples that don’t belong: upgraded appliances, an added outdoor kitchen, or anything else the client decided they wanted. Those are change orders.
Who owns the contingency?
Whoever the contract says, and if the contract doesn’t say, you’ll find out who thinks they own it at the worst possible moment. There are really two kinds.
Builder’s contingency. On a fixed-price contract, the builder has taken the risk of cost overruns within the agreed scope, so the builder carries a contingency inside the price. It’s generally the builder’s to spend and the builder’s to keep. The client usually doesn’t see it as a line item.
Owner’s contingency. On a cost-plus contract, the owner pays actual costs, so the contingency is a visible line in the owner’s budget. The builder typically needs approval to draw on it, and what isn’t spent stays with the owner.
Separately from both, I like clients to hold their own reserve for the changes and upgrades they’ll want during the build. That one has nothing to do with unforeseen conditions. It’s for the day they see the framing and want a bigger window. I wrote about it in Happy Client Hack: Client Contingency.
The contract type drives all of this, so it’s worth understanding cost-plus vs. fixed-price before you decide how to present contingency. Have your attorney confirm the contract language matches what you’ve told the client.
How should you use and track construction contingency?
Treat it like a bank account with a ledger, not a slush fund.
Define allowed uses in writing. A short list of what contingency is for and what it isn’t.
Require approval for every draw. Yours on a builder’s contingency, the owner’s on an owner’s contingency.
Log each draw. Date, amount, reason, and the remaining balance.
Compare the balance to progress. If half the contingency is gone before the slab is poured, you have information. Act on it.
Release it as risk passes. Once you’re out of the ground and dried in, much of the uncertainty is behind you.
Review it at closeout. What you spent it on is the best lesson you’ll get for estimating the next job.
A contingency only works inside a budget where every other line is real. Our Budget and Specifications Template lays out the budget and the specs together, so the contingency is covering true unknowns and not gaps in the estimate.
How do you carry less contingency without taking more risk?
Shrink the unknowns. Contingency is a price you pay for missing information, so the cheapest way to reduce it is to go get the information.
Get a soils report and a survey before you price the foundation.
Finish the specifications before you sign. See construction budget and specifications.
Get written bids from the trades on the actual plans.
Make selections early, so allowances turn into real numbers.
Put unforeseen conditions in the contract, so everyone knows whose cost they are.
Frequently asked questions
Is 10% contingency enough for building a house?
For many new homes with complete plans, something in the 5% to 10% range is common, but it depends on the site, the documents, and the market. A remodel or a difficult lot can justify more.
What happens to unused construction contingency?
It goes to whoever owns it under the contract. Generally that’s the builder on a fixed-price job and the owner on a cost-plus job.
Is contingency a hard cost or a soft cost?
It can be either. Many budgets carry a hard cost contingency on construction and a separate one on soft costs like fees and interest, and lenders have their own preferences. Ask your lender how they want it shown.
Can a client use the construction contingency for upgrades?
They shouldn’t. Contingency is for unforeseen costs, and spending it on upgrades leaves nothing for the surprises it was meant to cover.
BTW, if you want a budget solid enough that your contingency only has to cover real surprises, grab our Budget and Specifications Template over at the Building Optimal Shop, where you can check out the rest of our swag to build a better business. Proceeds go to benefit, Exponencialistas, my non-profit investing in entrepreneurs transforming their communities in Latin America.