Over-Improving a Home: When Renovation Doesn’t Pay

An upscale primary suite addition costs a national-average $339,513 and adds $81,042 to resale value — a recovery of 23.9 cents on the dollar, per the 2025 Cost vs. Value Report from Zonda and the Journal of Light Construction. The remaining $258,471 does not vanish. It buys daily comfort, square footage, and a finished space the owner enjoys. But as a resale proposition, it is one of the worst-performing projects the report tracks.

That gap — between what a renovation costs and what the market will pay for it — is the entire subject of over-improvement. The phenomenon is not about bad taste or shoddy work. It is about spending past the point where a neighborhood, a price tier, or a buyer pool will reimburse the spend. For households earning $150k or more, the projects most likely to over-improve are precisely the ones this income bracket gravitates toward: gut kitchens, suite additions, spa bathrooms, and bespoke build-outs.

The numbers that define over-improvement

Over-improvement has a measurable signature: a project where the cost climbs faster than the resale value it generates. The 2025 Cost vs. Value Report makes this visible by tracking both numbers side by side for 28 project types. The pattern is consistent — as scope and finish level rise, the percentage recovered falls.

Source: 2025 Cost vs. Value Report, Zonda/Journal of Light Construction/Remodeling. National averages.

The minor kitchen remodel is the only interior project in the report’s national top five. It returns more than it costs. Spend roughly four times as much on an upscale gut renovation, and recovery collapses to 38 percent. The money does not disappear, but the market’s willingness to reimburse it does. That is over-improvement stated in a single line item — and it tracks closely with the broader kitchen remodel cost by tier.

Why the curve bends downward

Two forces drive the recovery percentage down as spending rises. The first is buyer-pool dilution. A $28,000 cosmetic refresh appeals to nearly everyone shopping in a given price band. A $160,000 custom kitchen with paneled appliances and a secondary scullery appeals to a narrow slice of that same band — and the buyers who want it often already have it.

Subjectivity is the second force. Clay DeKorne, chief editor of Zonda’s JLC Group, framed the 2025 results around a recurring tension: large interior remodels can be deeply rewarding to live in, yet their appeal is often too subjective to deliver the same return when it’s time to sell. Exterior replacements win on ROI precisely because they are universal — every buyer wants a sound roof and an intact garage door. Nobody negotiates over whether the entry door should be brass or matte black.

The 2025 report also confirmed that exterior home improvement projects consistently deliver more value at resale than larger discretionary interior remodels, with eight of the top ten projects being exterior replacements. The garage door replacement led for the second consecutive year, returning 268 percent on a $4,672 average cost. That figure is the structural inverse of the upscale suite addition: low cost, universal appeal, near-total recovery. Understanding the full spread requires the broader renovation ROI by project type dataset.

The Finluxy Renovation ROI Index, project by project

To compare projects on equal footing, every figure below is expressed as the Finluxy Renovation ROI Index — the percentage of project cost recovered in added resale value, drawn from 2025 Cost vs. Value Report data. An index of 100 means break-even. Most projects land well below it.

Source: 2025 Cost vs. Value Report, Zonda/Journal of Light Construction/Remodeling. Finluxy Renovation ROI Index = (resale value added ÷ project cost) × 100, calculated by Finluxy from the report’s national-average figures.

The index reveals something the raw cost figures hide. The upscale primary suite addition does add the most total dollars of value of any interior project — $81,042 is real money. But it requires $339,513 to unlock it, and the $258,000 difference is the over-improvement penalty in cash terms. A household weighing that project against its full primary suite addition cost breakdown should treat the comfort and the resale math as two entirely separate ledgers.

Where the budget actually goes

Over-improvement is not only a function of finish level. It compounds through the cost structure itself, because soft costs scale with the size of the project. The cluster’s total-cost model breaks a project into hard costs (materials and labor) and soft costs (design, permits, and the contingency reserve). On a $339,513 suite addition, the soft-cost layer alone can run into six figures.

Consider how the soft costs stack on a large addition. Architect and designer fees typically run 10 to 15 percent of the project budget. A contingency reserve of 15 to 20 percent of hard costs is standard for additions involving new foundations and structural tie-ins. Permits and inspections add a variable but non-trivial line. None of these produce a single square foot of finished space a buyer can see — yet they are unavoidable, and they are entirely absent from the resale value the market assigns.

Cost-structure framework: Finluxy total-cost-of-ownership model. Percentages reflect standard industry ranges for major additions; actual figures vary by market and project.

The contingency reserve deserves particular attention on over-improvement-prone projects, because older homes hide expensive surprises behind their walls. Setting that number correctly is its own discipline — too low and the budget breaks mid-project, too high and capital sits idle. The mechanics of a proper renovation contingency budget matter most precisely on the large additions where over-improvement risk is highest. Design fees follow a similar logic; the structure of architect fees for home renovation means a bigger budget mechanically generates a bigger soft-cost bill.

The insight most coverage misses

Nearly every renovation article frames ROI as a property of the project — “kitchens return X, bathrooms return Y.” The 2025 data shows that framing is incomplete. ROI is a property of the project relative to its market position. The same upscale kitchen that recovers 38 percent nationally recovers materially more in a Pacific-region luxury market and materially less in a neighborhood where it pushes the home above the top comparable sale.

Here is the specific thing the dataset reveals that the headline percentages bury: the over-improvement penalty is largest exactly where $150k+ households are most likely to spend. The four lowest-recovering projects in the comparison above — upscale kitchen, upscale bath addition, upscale primary suite addition — are all premium-tier interior projects. The report’s own structure shows that moving from “midrange” to “upscale” within the same project category consistently shaves recovery, with upscale kitchen ROI declining and upscale primary suite additions dropping nearly six percentage points year over year. The penalty is not random. It is concentrated in the high-finish, high-budget tier — the tier this income bracket defaults to. A household pursuing a luxury home renovation cost guide is, by definition, operating in the steepest part of the curve.

What this means for a $150k+ household

The decision is rarely whether to renovate. It is how to sequence comfort against recovery, and the two goals pull in opposite directions at the top of the budget. A household planning to sell within a few years should treat the Finluxy Renovation ROI Index as a hard constraint — anything below roughly 70 percent is a deliberate purchase of lifestyle, not an investment, and should be sized accordingly. A household planning to stay ten or fifteen years can rationally ignore the index, because the daily-use value of the space accrues over a long horizon that resale math never captures.

The trap specific to this income level is the neighborhood ceiling. A $339,513 suite addition on a home near the top of its block’s comparable sales does not lift the home above the ceiling buyers will pay for that location — it simply makes the owner the most over-built house on the street, the one that sits longest and sells at the largest discount to cost. The disciplined move is to size the project to the home’s position in its market, not to the household’s available budget. Before committing to a premium-tier project, three questions settle most of the analysis: what do the top comparable sales in the neighborhood actually clear, where does this project’s Finluxy Renovation ROI Index land in the table above, and how many years until a likely sale. The answers convert an emotional decision into a defensible one — and for the projects at the bottom of the index, they often argue for spending less, not more.