How accurate are Formaus cost estimates?
Formaus cost estimates are honest by design: they're labeled as assumptions, presented as ranges, and built to be verified — not believed blindly. The Hidden Cost Alert in a Score Report estimates major-system costs (HVAC, roof, water heater, and similar) from the home's age and typical system lifespans, and every such figure carries an explicit label and the instruction to verify with the seller or an inspection.
How the estimates are built
| Element | How it works |
|---|---|
| System age model | A home's build year implies system ages; each system has a typical lifespan (e.g., roofs commonly 20–30 years) |
| Cost ranges, not points | Each flagged system shows a replacement cost range, reflecting real market variation |
| Assumption labels | Estimates assume original systems unless known otherwise — and say so on the report |
| Verification prompts | Each flag doubles as a question for the seller's disclosure or your inspector |
Why "labeled assumption" beats false precision
No remote analysis can see whether a 1993 home's furnace was replaced in 2019 — and any tool claiming exact repair costs without physical verification is overpromising. What a pre-offer buyer actually needs is different: which systems could plausibly need money soon, roughly how much, and what to ask. That's negotiation-grade information — it feeds the report's suggested offer range and repair leverage (what the report contains) — and it's exactly what the estimates deliver.
What sharpens or limits accuracy
- Sharpens: listing details confirming replacements, seller disclosures, permit history — bring these to the numbers
- Limits: anything inside walls, unrecorded repairs, condition beyond age — the same limits any photo-and-data analysis has
- Regional variation: replacement costs differ by market; ranges reflect this, local quotes settle it
The rule of use: treat every estimate as a question with a dollar range attached, then get it answered — by the disclosure, the inspection, or a contractor quote.