The improvement-versus-repair line decides more home-sale tax bills than any other single question in the basis rules — and it is answered when the work is done, not in the year of the sale. This page is general information, not tax advice — talk to a CPA or tax professional on your own facts. The companion guides are How do you calculate your home's basis? and Do you pay capital gains tax when you sell your house?
A capital improvement is defined by its effect: it adds to the home, prolongs its useful life or adapts it to a new use. Practitioners summarize the tax regulations behind that test as betterment, adaptation or restoration — the work fixes a condition that existed when you bought the home or materially improves the home beyond it, converts part of the home to a meaningfully different use, or brings a major component or system back to working order by replacing it. IRS Publication 523, Selling Your Home and Publication 551, Basis of Assets carry the homeowner lists this page follows. If the work only keeps the home in its ordinary working condition, it is a repair or maintenance, and it does not add to basis while the home is your residence — however necessary, and however large the bill.
The qualifying work falls into recognizable families. Additions and structural work: a new bedroom, bathroom, second story, garage, porch or deck, and finishing an unfinished basement or attic into living space. Whole rooms: a full kitchen or bathroom remodel, including the cabinetry, counters and built-in appliances installed in it. Whole systems: a new roof, a replaced furnace or central air system and its ductwork, whole-house repiping, a rewired electrical system, a new water heater, a septic system, a water softener or filtration system, a built-in security system, a central vacuum and a lawn sprinkler system. The shell: new siding, insulation, storm windows and doors. The site: a paved driveway or walkway, a fence, a retaining wall and a swimming pool. In every family the pattern is the same — a whole component, system or space, added or replaced, that will still be part of the home years from now.
The non-qualifying side is the everyday work of owning a home: repainting, fixing leaks, patching drywall or a roof section, replacing a few shingles or one broken window pane, repairing a single appliance, unclogging drains, servicing systems and cleaning gutters. These keep the home working as it already was; they do not add a room, a system or years of life beyond its ordinary span. The contrast cases teach the line better than any definition: patching a roof is maintenance, replacing the roof is an improvement; replacing a broken pane is maintenance, replacing the windows throughout the home in one project is an improvement; repainting a scuffed room is maintenance. Cost does not move the line — the IRS applies no dollar threshold — and neither does urgency: an emergency repair is still a repair.
One rule rescues a lot of honest paperwork: repair-type work done as part of an extensive remodeling or restoration project is generally counted as part of that improvement. When a kitchen is gutted and rebuilt, the repainting, patching and minor fixes inside that project are not carved out as maintenance — the project is one improvement, figured at its whole cost. The same logic covers a restoration that returns a deteriorated home to working order. What the rule needs is a real project: one plan, one scope, documented together. A scattered year of unrelated small fixes does not become an improvement by being added up afterward, which is why the contract and invoices for a remodel should describe the whole scope of the work, repairs included, in one file.
A capital improvement on a main home gives no deduction in the year it is paid for. Its cost is added to your home's basis, and it does its work later: at a sale, the gain is the amount realized minus the adjusted basis, so documented improvements lower the gain before the Section 121 main-home exclusion is applied under its own tests — the full sequence is worked in How do you calculate your home's basis? and Do you pay capital gains tax when you sell your house?. Two adjustments ride along: an improvement for which a federal energy credit was claimed generally has its basis increase reduced by the credited amount, and an improvement that was later removed or replaced — the first new roof, once the second one goes on — no longer stands in basis at its old cost.
Basis is a records test as much as a work test. For every project, keep the contract, the invoice and proof of payment, with the date and a plain description of what was done — whole roof or patch, whole system or part — because that description is what places the work on the right side of the line years later. Keep the file for as long as you own the home and for the years after a sale when the return can still be examined. In Homeowner HQ, the same habit runs the monthly record: correct the facts about your home — its systems, updates and condition — through your agent's fix-my-facts record, so the improvement history is already gathered in one place when a sale year comes, instead of reconstructed from memory.
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A capital improvement is work that adds to your home, prolongs its useful life or adapts it to a new use — the tax rules describe the same idea as a betterment, an adaptation or a restoration. IRS Publications 523 and 551 list the common examples for a home: an addition — a bedroom, a bathroom, a deck, a porch, a garage; a full kitchen or bathroom remodel; a new roof; installing or replacing a whole system — heating, air conditioning, plumbing, electrical wiring, a water heater, a septic system; finishing a basement or attic; new flooring laid as part of a remodel; insulation and storm windows; a built-in security system, a central vacuum or a lawn sprinkler system; and permanent site work such as a paved driveway, a fence, a retaining wall or a swimming pool. The test is what the work does to the home, not what it costs: there is no dollar threshold, and an expensive repair is still a repair. This page is general information, not tax advice.
Work that keeps your home in its ordinary working condition — ordinary repairs and maintenance — does not count while the home is your residence. Repainting a room, fixing a leak, patching drywall, replacing a few broken shingles or a single broken window pane, unclogging a drain, servicing the furnace and cleaning the gutters are repairs and maintenance: they restore the home to the condition it was already in rather than adding to it, adapting it or extending its life. The whole-system line is what decides most real cases: replacing the entire roof is an improvement, patching one section is a repair; replacing all the windows in a project is an improvement, replacing one broken pane is a repair. One exception matters: repair-type work done as part of an extensive remodeling or restoration project is generally counted as part of that improvement — repainting done inside a full kitchen renovation is part of the renovation's cost, not a standalone repair. Keep the invoices either way, because the project paperwork is what shows which side of the line the work fell on.
It raises your basis. A capital improvement on your main home is not deducted in the year you pay for it; instead, what it cost is added to your home's basis, and when you sell, the gain is the amount realized minus that adjusted basis — so every documented improvement lowers the gain the tax is figured on, and the Section 121 main-home exclusion is then applied to the gain under its own tests, as the capital gains guide explains. Two adjustments ride along: if a federal energy credit was claimed for an improvement, the rules generally require basis to be reduced by the credited amount, and an improvement that was later removed or replaced no longer stands in basis at its old cost. The proof is the record — the contract, the invoice and proof of payment for each project, kept with the closing file — because an improvement you cannot document at sale time is an improvement you cannot honestly count. The companion guide, How do you calculate your home's basis?, works the full calculation.