WhatHomeCosts
ExteriorFoundation & WaterYard & PestsCalculators

Methodology

Every price on WhatHomeCosts is a range built from published, dated sources, not a guess. This page explains how we build and check those ranges.

Where our prices come from

  • National cost databases and guides that aggregate real project data, such as Angi/HomeAdvisor, HomeGuide, Fixr, This Old House, Forbes Home and similar publishers.
  • Contractor and manufacturer price pages when they publish prices (we label brand pages as market estimates when the company does not publish national prices).
  • Government and nonprofit sources for safety and regulatory context, such as the EPA for radon, mold and asbestos.

Each guide lists its sources, with the date each page was last updated, at the bottom of the article.

How we build a range

  1. We collect prices from at least two independent sources, preferring data updated in the last 12–18 months.
  2. When sources disagree, we use the range where they overlap and explain the gap in the text.
  3. We split totals into materials, labor, permits, disposal and a contingency so you can compare quotes line by line. When a source does not split costs, the split is our estimate and we say so.
  4. We check that the quick answer, tables, breakdown and calculators agree with each other, and that smaller guides fit within their main guide's range.

Calculators

Our calculators multiply your project size by unit prices from the matching guide, then apply adjustments for access, complexity and region. Regional factors (from about 0.85× in lower-cost areas to 1.35× in the most expensive metros) and some adjustment factors are WhatHomeCosts estimates; each calculator says which. Results are always shown as a range.

Limits

Prices are national averages. Your local market, the condition of your home, code requirements and the season can push a real quote outside our range. Use our numbers to budget and to compare quotes, and always get at least three written quotes.

How often we update

We review high-traffic guides at least once a year and whenever we see a meaningful price change. Each page shows the date its prices were last checked. Spot an outdated number? Tell us.