Homeowners Keep Seeing Renovation Budgets Change Midproject: What’s Causing the Costly Surprises

Whether you’re tackling a bathroom renovation, kitchen refresh, or anything in between, your budget should be top of mind.

It’s your responsibility to work with your contractor to come up with a realistic spending plan for everyone involved. 

Once you do, however, don’t be surprised if it changes. 

According to Angi's 2026 State of Home Spending Pulse, 43% of homeowners who recently hired a professional to complete a home project exceeded their initial estimate.

Among those who went over budget, more than one-third spent at least 30% more than they planned.

Since midproject budget changes can take a toll on your finances, it’s important to be proactive and prevent them as much as possible. Otherwise you may end up with a home renovation that costs far more than you anticipated. 

Why renovation budgets change midproject

One of the biggest reasons renovation budgets increase after a project has started is a lack of alignment between you—the homeowner—and your contractor around the scope of work and overall expectations. 

“For example, a contractor may include drywall patching and painting in the areas where work is being done, while you may expect the entire house to be painted. If you later decide you want the whole house painted, that becomes additional work and an additional cost,” explains Trent Klatte, co-founder and CEO at West End Construction Corp. in Culver City, CA.

Also, a budget may change because a contractor discovers something they didn’t know was there that makes the entire project more expensive. 

“The biggest driver isn't labor or materials in isolation; it's what's discovered once work begins. In the [San Francisco] Bay Area, where a large portion of the housing stock was built in the 1960s and '70s, opening walls and floors routinely surfaces electrical panels at capacity, galvanized plumbing that should have been replaced a decade ago, and subfloor damage that wasn't visible from above,” says  Keith Ostendorf, project developer at Next Stage Design + Build in San Jose, CA.

Joe Matejka, president and founder at Walk Your Plans in Cleveland, reinforces the fact that a “simple” change can become very expensive once multiple trades are involved.

"Let’s say you decide you want a kitchen island moved or resized. This could affect cabinetry, countertops, electrical, plumbing, and flooring. If materials have already been ordered, you may have to pay to replace something you already purchased, and the change can also impact the project schedule," Matejka explains.

And though you’re a homeowner, you might not necessarily be a pro at managing renovation projects, so you simply may not know everything you need to think about upfront. 

“The best situation we see is when there is an experienced designer or project manager involved who can help flesh out the scope of work, identify what the homeowner really wants, and ensure the quote is as detailed as possible,” Klatte says.

Additionally, while the cost of materials has definitely increased over the past few years, driven by tariffs and overall inflation, it shouldn’t be a blanket explanation for every added expense. 

“A contractor should be able to explain which material changed in price and whether that purchase was already secured. Higher market prices don’t, by themselves, explain why an agreed project budget changed,” explains Sean Kviyat, renovation expert and owner of Iconiq Construction in Seattle. 

How to prevent a budget from spiraling once work begins

Fortunately, there are steps you can take to keep your original budget and your final budget as close as possible.

Get a fixed-price budget before the work begins

A time-and-materials contract shifts all cost risk to the homeowner; a fixed-price contract puts it on the contractor to estimate accurately. 

“This is the single most protective thing a homeowner can do,” says Ostendorf.

Budget for systems before you budget for finishes

If your home was built before 1985, set aside a contingency specifically for electrical, plumbing, and structural findings—separate from the finish allowances. 

“A reasonable figure is $30,000 to $75,000 depending on the home's age and condition and the area you’re in. If you don't spend it, you keep it. If you need it, you're not making panicked decisions midproject,” Ostendorf explains.

Freeze the scope before construction starts

Every change order after work begins costs more than the same decision made during design. The time to decide on the island size, the tile choice, and the appliance spec is before the first wall comes down. 

“A contractor who lets scope keep expanding midproject is not doing you a favor,” Ostendorf says.

Clarify what’s included—and what’s not

Figure out exactly what your quote covers. 

“Ask ‘What decisions are still missing from this price?’ That question can uncover allowances, excluded work, and assumptions that otherwise surface during construction,” says Kviyat.

Get the scope, exclusions, selections, and process for unexpected conditions in writing. Clarify which prices are secured, which can change, and who is responsible for those changes. 

“Don’t forget to agree on a contingency appropriate to the project, and keep it available for necessary work,” Kviyat adds.