Home Vulnerability Assessment Calculator
Evaluate your home's overall vulnerability by answering questions across key risk categories. Each category is weighted to produce a composite risk score with actionable recommendations.
1. Structural & Age Factors
2. Natural Disaster Exposure
3. Security & Access Control
4. Fire Safety
5. Water & Moisture Risks
Formula
Composite Vulnerability Index (0–100) =
(Structural Score × 0.20) + (Natural Disaster Score × 0.25) +
(Security Score × 0.20) + (Fire Safety Score × 0.20) + (Water Score × 0.15)
Category scores are weighted averages of their sub-factors, each normalised to 0–100:
- Structural (20%): Home age (30%) + Roof age (25%) + Foundation type (30%) + Inspection recency (15%)
- Natural Disaster (25%): Flood zone (30%) + Wind exposure (30%) + Seismic zone (20%) + Wildfire risk (20%)
- Security (20%): Lock quality (40%) + Alarm system (40%) + Exterior lighting (20%)
- Fire Safety (20%): Smoke detectors (35%) + Fire extinguisher (20%) + Electrical condition (45%)
- Water & Moisture (15%): Plumbing age (30%) + Sump/drainage (35%) + Roof condition (35%)
Dropdown options are scored on a 1–4 scale (1 = best practice, 4 = highest risk).
Normalised score = (option value − 1) / 3 × 100.
Continuous inputs (age fields) are scaled against empirical thresholds (e.g., roof lifespan ≈ 30 years, plumbing lifespan ≈ 50 years).
Risk bands: 0–19 Very Low | 20–39 Low | 40–59 Moderate | 60–79 High | 80–100 Very High
Assumptions & References
- Category weights reflect relative contribution to residential loss as reported in IBHS (Insurance Institute for Business & Home Safety) research.
- Flood zone classifications follow FEMA's National Flood Insurance Program (NFIP) designations.
- Seismic zones are based on USGS National Seismic Hazard Maps (NSHM).
- Wildland-Urban Interface (WUI) definitions follow USDA Forest Service and CAL FIRE guidelines.
- Roof lifespan threshold of 30 years is consistent with asphalt shingle manufacturer warranties and NRCA guidelines.
- Plumbing lifespan of 50 years applies to copper supply lines; galvanized steel and polybutylene may fail sooner.
- Electrical fire risk weighting reflects NFPA data showing electrical failures account for ~13% of home structure fires.
- Security scoring aligns with ANSI/BHMA Grade 1 lock standards and UL-listed alarm system classifications.
- This tool does not account for local building codes, insurance policy specifics, or site-specific microclimate factors.
- Results are indicative only. A licensed home inspector should be consulted for a definitive assessment.