Methodology · Overview
Methodology
Reviewed by Byron Malone · Last reviewed .
Every calculator on Renovation Costs Hub is a real piece of software with tests, a citation, and a named human who reviews it. For category-specific methodology — sources, formula derivations, edge cases, and update protocol — see the per-category pages linked at the bottom. For how Bedrocka Tools operates as a publisher more broadly, see our editorial standards.
How tools are built
Calculators are written in TypeScript as pure functions inside a shared package (@bedrocka-tools/calc), with Vitest unit tests that cover edge cases and every published sample problem we can find from primary sources. If a calculator gives the wrong answer, there is one file to fix and a failing test that tells us it was wrong.
Formula sourcing — primary sources only
We only cite primary sources. Blog-of-a-blog-of-a-PDF is not a source. Secondary sources (industry benchmarks, whitepapers) are used only where a primary source does not exist, and always labeled as such.
Review process
- Draft: calculator logic and explanatory copy are drafted with the primary source pulled up and every non-trivial number checked against it.
- SME review: each calculator is reviewed by a named human with operator experience in the domain.
- Citation verification: every URL cited is spot-checked at publish time.
- Publish: with a
Last updatedstamp anddateModifiedschema.org field on every page.
Update cadence
Every calculator is reviewed quarterly and updated immediately whenever a primary source (regulation, rate table, or agency guidance) changes.
Error reporting
If a calculator gives the wrong answer, email info@bedrockatools.com with the tool, the inputs you used, and the output you got. We respond within 3 business days; corrections are published on our corrections page.
Per-category methodology
- ROI by project— Cost vs. Value methodology, Remodeling Magazine, NAR Remodeling Impact.
- Home equity financing— HELOC, HEL, cash-out refi — IRC 163(h), CFPB disclosures.
- Budget and contingency— contractor markup, contingency rates, material/labor splits.
- Resale value— appraisal methodology, MLS comp analysis, location factors.
Limitations
Calculators on this site are estimates for educational use. They do not account for every lender feature, every tax treatment in every state, or your individual circumstances. They are not financial, investment, legal, or tax advice. Consult a licensed professional for decisions with real dollars attached.