Methodology

This page explains how the RestorationCalcs calculators are derived and verified — and why they need no ongoing maintenance to stay correct.

1. Timeless math, stable conventions

Every tool computes from a closed-form formula: restoration/remediation cost = (affected sq ft × your $/sq ft × category/severity multiplier + Σ line items) ×(1 + contingency); water extraction = max(area × rate, minimum fee); air movers = ceil(area ÷ coverage); dehumidifiers = ceil(area ÷ LGR coverage); required scrubber CFM = ACH × room volume ÷ 60, and ACH = CFM × 60 ÷ volume; radon = (base system + extra points × rate) ×(1 + contingency); inspection = base fee + samples × rate; insurance out-of-pocket = max(0, min(covered loss, damage) − deductible). The only baked-in numbers are stable identities (27 cu ft per cu yd, 0.623 gal per sq ft per inch, the 60 min/hr in the ACH identity), EPA thresholds (mold ~10 sq ft, radon 4 pCi/L) and labeled IICRC/AHAM sizing and cost-band typicals. These do not drift, so the statements stay true over time.

2. No prices, no feeds

There is deliberately no restoration or labor price, no regional cost index, no contractor directory and no live rate. Every cost tool works on the prices you enter from your own quotes and bills ($/sq ft, $/ft, $/day, $/hr, $/vent, $/sample, $/point). Labeled cost bands are shown only as a sanity guide. That is why the site is correct regardless of what restoration, labor or material prices do.

3. Numeric self-check

Every formula is asserted against a worked example with known numbers (for instance: a 500 sq ft water loss at $4.50/sq ft with $600 of equipment is about $3,135 and needs roughly 9 air movers and 1 LGR dehumidifier; 200 sq ft of mold at $15/sq ft is $3,000; a typical radon system is about $1,870; a 2,700 cu ft room at 4 ACH needs 180 CFM; out-of-pocket on a $15,000 loss with a $1,000 deductible is $14,000). A release gate runs all of these and fails on any mismatch, so "verification" here is mathematical correctness plus accurate conventions — not a time-based check.

4. Estimate, not a bid, protocol or opinion

The category/severity multipliers, equipment coverage, ACH targets and cost bands are labeled planning typicals — a starting point, not a spec. Every result is a planning estimate or an equipment-sizing typical: get itemized written quotes from licensed, insured, IICRC-certified restoration contractors. Category 2/3 water, sewage and biohazard are health hazards — hire certified pros and do not DIY Category 3. Mold over about 10 sq ft usually needs a professional (EPA); radon is a serious health risk (EPA 4 pCi/L — use an NRPP/NRSB mitigator); asbestos and lead are regulated hazardous materials handled by licensed contractors only. The insurance estimator is illustrative only. Nothing here is a remediation protocol, an abatement design, or medical, insurance or legal advice.