How our estimates work

1. National planning figures

Each of the 27 projects has a national cost midpoint for a standard specification and a typical share of cost recouped at resale. These are adapted from the ranges seen in widely cited public research: Remodeling magazine's annual Cost vs. Value report, the National Association of Realtors' Remodeling Impact report, and NKBA and ENERGY STAR guidance for kitchens and energy upgrades. We round them and do not reproduce any report's tables. RenovROI is not affiliated with any of these organisations.

2. Regional factors

Each US Census division gets a cost index and a value index (national = 1.00). Cost is multiplied by the cost index; value added by the value index. Their ratio is why the same project recoups more in some regions than others.

3. Home-value adjustment

If you enter your home value, we compare the project's cost with it. Projects under about 2% of home value get a slight lift; between 2% and 10% the return eases off gently; above 10% it falls faster, because large projects on modest houses tend to outrun what comparable sales support. The factor is clamped between 0.55 and 1.05.

4. Your own quote

On project pages you can enter a contractor's price. Value then scales with the square root of the price change: paying twice the typical price does not double what buyers will pay. This mirrors the diminishing-returns explainer on the home page.

What the numbers can't know

• The condition of your house and your street.
• How hot your local market is this month.
• Whether your finish choices suit buyers in your price band.
• The value of enjoying the project while you live there.

Use the results to rank and prioritise. Before spending, get at least two written quotes and ask a local agent what recently sold comparable homes had.