What Home Improvements Increase Property Taxes?

Home improvements that add significant square footage or functional living space, like finished basements, room additions, garages, and major kitchen or bathroom remodels, are the most likely to increase your property taxes. Cosmetic updates like paint, flooring, or landscaping generally do not trigger a reassessment on their own, since they tend to improve appearance without meaningfully changing the home’s assessed value.

For homeowners planning a renovation in Central Ohio, it is worth understanding how these projects can affect your property tax bill before you start, not after the county reassesses your home and the higher bill shows up unexpectedly.

How Property Taxes Are Calculated in Ohio

Ohio counties assess property values periodically, and your property tax bill is based on that assessed value multiplied by your local tax rate. County auditors conduct full reappraisals every six years and update values partway through that cycle as well, but they also adjust individual property values when a permit is pulled for a significant improvement, rather than waiting for the next scheduled reappraisal.

This means a major renovation can trigger a reassessment of your specific property outside of the county’s normal cycle, even if your neighbors’ homes are not being reappraised at the same time. Understanding this distinction matters if you are budgeting for a renovation and want to factor in the ongoing cost, not just the upfront construction cost. This is a common topic we help clients think through as part of broader tax planning conversations.

Home Improvements Most Likely to Increase Property Taxes

Generally, the improvements most likely to raise your assessed value, and therefore your property tax bill, are ones that meaningfully increase the size or usable space of your home. Common examples include:

Finishing a basement or attic into livable space
Building a room addition or expanding the home’s footprint
Adding a garage, sunroom, or other permanent structure
Major kitchen or bathroom remodels that involve permits
Adding a swimming pool or significant outdoor living structure
Converting a garage into additional living space

These projects typically require a building permit, and permits are one of the main ways county auditors find out about improvements between full reappraisal cycles. The bigger the increase in square footage or overall functionality, the more likely the county is to adjust your assessed value upward.

Home Improvements That Usually Do Not Increase Property Taxes

Not every improvement affects your tax bill. Cosmetic and maintenance-focused projects tend to improve a home’s appearance or livability without significantly changing the assessed value used for taxes. These often include:

Interior and exterior painting
New flooring or carpet
Replacing an existing roof, without expanding the structure
Updating fixtures, cabinet hardware, or countertops without a full remodel
Landscaping and general yard improvements
Replacing windows or doors with similar-sized units

These projects can still improve your home’s market value when you eventually sell, but because they do not typically require a permit tied to structural changes, they are much less likely to trigger a reassessment in the meantime.

How Does the County Find Out About a Renovation?

The most common way is through building permits. When you pull a permit for a renovation, that information is generally shared with, or accessible to, the county auditor’s office. Auditors may also identify changes through periodic property inspections, aerial imagery, or when a home is sold and reappraised as part of that transaction.

Skipping the permit process to avoid a reassessment is not something we would recommend. Beyond the legal and safety risks of unpermitted work, it can create real problems later, including issues with insurance claims, complications when selling the home, and potential fines if the work is discovered during an unrelated inspection or sale.

When Does the Higher Tax Bill Take Effect?

Reassessments tied to a specific renovation typically take effect the tax year following the completion of the work, though timing can vary somewhat by county and when the permit was closed out. This means there is often a gap between when a renovation is finished and when the higher property tax bill actually arrives, which can catch homeowners off guard if they were not expecting the change.

That gap can work in a homeowner’s favor if you plan for it. Setting aside the estimated increase during the renovation itself, rather than waiting for the new bill to show up, can make the transition to a higher tax payment much less disruptive to your budget.

Can You Appeal a Reassessment After a Renovation?

Yes. If you believe your new assessed value is too high relative to the actual market value of your home, most Ohio counties allow homeowners to file a complaint with the county Board of Revision, generally within a specific window after the new valuation is issued. This process typically requires supporting evidence, such as a recent appraisal or comparable sales data. If you are unsure whether your reassessment seems accurate, it can help to review the numbers with a professional before deciding whether an appeal is worth pursuing, especially if the renovation is tied to a real estate investment property rather than your primary home.

How to Plan Ahead Before a Major Renovation

If you are considering a significant renovation, it is worth building the potential property tax increase into your overall budget, not just the construction costs. A few things can help:

Ask your contractor or county auditor’s office how similar projects have affected assessed values in your area
Factor an estimated ongoing tax increase into your renovation budget, not just the one-time construction cost
Keep detailed records of the project scope and costs in case you need them for an appeal later
Talk to your CPA about how the renovation might interact with other tax considerations, especially if the property is a rental or investment property rather than your primary residence

Does the Size of the Increase Depend on the Project’s Cost?

Not exactly. Property tax assessments are based on the added market value of the improvement, not necessarily the dollar amount you spent on it. Two homeowners could spend the same amount on a renovation and see different tax impacts depending on how much that specific improvement is estimated to add to the home’s market value in their area. A finished basement in a neighborhood where finished basements are common and expected may add less relative value than the same project in an area where most homes do not have one.

This is one more reason it helps to have a real conversation about a planned renovation before it starts, rather than assuming a rough percentage of the project cost will translate directly into higher taxes. Local market conditions and comparable homes in your area play a bigger role in that estimate than most homeowners expect.

This is part of why it can be hard to predict the exact tax impact of a renovation in advance. County auditors use standardized methods to estimate added value based on the type and scope of the improvement, but those estimates do not always match the actual amount spent on labor and materials.

What About Improvements to a Rental or Investment Property?

The same general rules apply to rental and investment properties: improvements that add significant space or value are likely to increase the assessed value and the property tax bill. For investors, this is worth factoring into your return on investment calculations before starting a renovation, since a higher property tax bill affects ongoing cash flow, not just the one-time renovation cost. This is a common consideration in our work with real estate investors, especially when weighing whether a renovation will actually improve the property’s overall return once the higher ongoing tax cost is factored in alongside increased rent potential.

Should You Avoid Renovating to Keep Taxes Low?

Generally, no. Most renovations that increase property taxes also increase the home’s market value and livability, often by more than the added tax cost over time. The goal is not to avoid improvements altogether, but to go into a project with a realistic understanding of the ongoing cost, so it does not come as a surprise later. For homeowners planning to stay in a home for many years, or investors evaluating a property’s long-term return, understanding the tax side of a renovation is simply one more input into a smart, well-informed decision, not a reason to skip a project that otherwise makes sense.

Get Help Planning Renovations Around Your Tax Picture

A renovation can be a great investment in your home, but it helps to go in with clear eyes about the ongoing property tax impact, not just the upfront cost. Hogan CPA Financial Services works with homeowners and real estate investors across Columbus and Central Ohio to plan ahead for these kinds of changes.

Contact us today if you are planning a major renovation and want to understand how it might affect your property taxes before you begin.