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How Home Improvements Can Increase Your Property Taxes

Remodeling can grow your home’s value but also raise your property tax. Here's how it happens and what it can cost.
Jan. 9, 2020
Home Ownership Costs, Mortgages
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You transformed your dingy basement into square footage you’ll actually use, with an entertainment room, a guest bedroom and a three-quarter bath. Yay! Dream realized. What’s more, the makeover will help boost your home’s value.

But added value from home improvements can also increase your property tax bill. If you’re thinking that the tax assessor won’t notice, you may be surprised.

Here’s how home improvements can cause a property tax increase and what to do if you want to dispute your property tax assessment.

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Improvements increase home value

Home improvements, depending on the project you choose, can enhance your home’s resale value. In 2017 (the most recent year for which data is available), a finished basement with an entertainment area and bathroom, for example, would raise a home’s sale price by an average of nearly $50,000, according to Remodeling Magazine. That’s less than the likely cost of the project, but still good news for your home equity.

But the property tax you pay is based on your home’s value. If its assessed value grows because of home improvements, your tax bill will grow, even if the tax rate stays the same, says Martin Marshall, county administrator in Lenawee County, Michigan. For example, in his area, a $53,000 basement remodel that adds $40,000 to a home’s value could push up the tax bill by $600, with no change in the tax rate, he says.

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The tax assessor spots the improvements

County tax assessors, sometimes called county appraisers, track the value of every piece of real estate in a taxing district, like a city or county. They maintain databases of local property values, often using sophisticated mapping software. Depending on a county’s size and budget, it can have many ways to detect changes in your home’s value, including these four common methods.

Inspections

The assessor’s field appraisers may just drive around, noticing changes. They typically stay outdoors unless the homeowner invites them in, says Greg McHenry, county appraiser in Riley County, Kansas.

If you enclose your patio or your porch, or you added on a whole room in the back and never pulled a permit for it, we would catch that during these review cycles.

Tim Boncoskey, CHIEF DEPUTY ASSESSOR, MARICOPA COUNTY, ARIZONA

The gigantic Maricopa County, Arizona (encompassing Phoenix, Tempe and Scottsdale), with $508 billion in real estate, is too big for the door-to-door approach. It uses a car and plane to photograph homes, says Tim Boncoskey, chief deputy assessor. “If you enclose your patio or your porch, or you added on a whole room in the back and never pulled a permit for it, we would catch that during these review cycles,” Boncoskey says.

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Building permits

Tax assessors monitor building and demolition permit applications to find changes affecting home values.

Boncoskey’s office watches all building permit requests. Whether your permit catches the assessor’s eye depends on the project and cost. But a homeowner spending $5,000 or more on a basement remodel, for example, should count on a visit, he says.

Tattletale neighbors

Neighbors occasionally tip assessors to unpermitted construction, usually because of a grievance or due to construction noise, Boncoskey says.

Comparable sale prices

Even if your basement renovation or your neighbor’s bathroom upgrade aren’t visible from the street, the increased value eventually creeps into your tax bill. How? Assessors track sale prices when homes change hands. They use those sale prices in reassessing tax values of nearby, similar homes. Over time, as neighbors upgrade homes and sell them for more, your home’s market value and its tax assessment rise, too.

“We wouldn’t know exactly an individual’s improvements if they didn’t have a permit. But, in due time, the market value of the entire neighborhood changes. So, then, the value is captured to the tax roll in the ensuing taxes,” says Boncoskey.

» MORE: See your options for financing home improvements

How to dispute property taxes

If you disagree with a tax bill, you can challenge the home’s assessed valuation. You’ll need to show that the assessed value doesn’t reflect your property’s true value.

Gather comparable listings or ask a real estate agent to pull records of comparable sales for you. Then call your assessor’s office to learn the dispute process. Aim to show that homes with similar tax values are better than yours. Start by discussing your findings by phone or in person. If you’re unsatisfied, you might be able to pursue the case with an independent tax appeals board.

» MORE: How property taxes work

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