Methodology & Data Transparency

How DOMI Score™ Works

DOMI Score™ is a composite property intelligence metric built from six verified data sources. We believe buyers deserve to know exactly how their risk score is calculated.

The DOMI Formula

D
Disaster Risk30%
O
Operational Cost25%
M
Market Intelligence25%
I
Infrastructure20%

// DOMI Score calculation (0–100)

DOMI = Disaster(30%) + Operational(25%)

+ Market(25%) + Infrastructure(20%)

// Crime score adjusts final output ±3 points

DOMI_final = clamp(DOMI_composite + crime_adj, 0, 100)

DOMI Score → Grade Conversion

A+ (90–100)
A (83–89)
A- (77–82)
B+ (70–76)
B (64–69)
B- (58–63)
C+ (52–57)
C (46–51)
C- (40–45)
D (30–39)
F (0–29)

Score Components

D

Disaster Risk

Weight: 30%

Evaluates exposure to natural disasters — primarily flood risk via live FEMA NFHL zone classification and NFIP insurance requirement. Earthquake and wildfire risk are scored from real USGS and NIFC historical event data; hurricane and tornado risk are modeled from state-level climatology, disclosed as estimated.

Scoring Factors

  • FEMA flood zone designation (X, A, AE, VE, etc.)
  • NFIP mandatory insurance requirement
  • Earthquake activity (USGS, live)
  • Wildfire history density (NIFC, live)
  • Hurricane/tornado risk (state climatology, estimated)

Data Sources

  • FEMA National Flood Hazard Layer (NFHL)
  • USGS earthquake catalog
  • NIFC fire perimeter history
  • NOAA severe weather archive (hail)
O

Operational Cost

Weight: 25%

Quantifies the ongoing financial burden of property ownership beyond the mortgage. Factors include a modeled insurance premium as a percentage of home value, effective property tax rate, HOA fee (where reported), and deferred maintenance signals from permit history.

Scoring Factors

  • Annual insurance premium / home value ratio
  • Effective property tax rate vs. county average
  • HOA fee and special assessment risk level
  • Deferred maintenance signals (aging systems)
  • Five-year ownership cost projection

Data Sources

  • Public tax rolls & county recorder data (assessed value, effective tax rate)
  • Rules-based insurance premium model
  • HOA fee (only where disclosed in source records)
M

Market Intelligence

Weight: 25%

Measures price trajectory and market liquidity using recent comparable sales and rental data. Signals include 1-year and 5-year price appreciation, days-on-market (DOM) velocity, and list-to-sale price ratio — all key indicators of demand strength.

Scoring Factors

  • 1-year price change vs. ZIP code average
  • 5-year appreciation compound rate
  • Average days on market (DOM) for comparables
  • List-to-sale price ratio
  • Current listing inventory levels

Data Sources

  • County recorder deed records (NYC ACRIS, FL DOR, NY ORPTS)
  • Zillow Research (ZHVI/ZORI, ZIP-level)
  • HUD Small Area FMR (rent baseline)
I

Infrastructure

Weight: 20%

Assesses the physical condition and system health of the property based on permit history. Open or unfinaled permits are a significant negative signal. System replacement dates for roof, HVAC, electrical, and plumbing are parsed from permit descriptions to estimate remaining useful life.

Scoring Factors

  • Open/unfinaled permit count (−12 pts each)
  • Roof age and replacement documentation
  • HVAC system age and permit history
  • Electrical/plumbing upgrades within 15 years
  • Overall permit activity density (well-maintained signal)

Data Sources

  • Live city and county permit systems in 48 jurisdictions via the BYB data network
  • Open-data portals, ArcGIS layers and Accela citizen-access sites
  • Reported as unavailable elsewhere — never estimated

Data Sources

FEMA NFHL

Federal Dataset

Updated: Quarterly

Official US government flood zone maps. Used to determine flood insurance requirements and parcel-level flood risk.

Property Records

Government / Public Records

Updated: Varies by county

Assessed value, recorded sales, and property facts from county recorder data (NYC ACRIS, FL DOR, NY ORPTS) and public tax rolls, with Zillow Research (ZHVI/ZORI) for ZIP-level value and rent trends.

FBI Crime Data

Federal Dataset

Updated: Annually

Violent and property crime rates by law enforcement agency, normalized per 100K residents — reported at the agency level, not per incident.

NCES

Federal Dataset

Updated: Annually

School enrollment, staffing, and test-proficiency data (Common Core of Data + EDFacts) — not GreatSchools.

Municipal Permit Records

Government Records

Updated: Varies by city

Real permit records from 48 live city and county sources via the BYB data network. Outside them the report states that permit history is unavailable for the address — it is never estimated.

Insurance Model

BeforeYouBuy Model

Updated: N/A

Estimated annual premium from flood zone, climate risk, crime score, and property age — not a live carrier quote or regulatory filing.

Data Confidence Scoring

Every BeforeYouBuy Homes report includes a Confidence Score (0–100%) that reflects data availability and freshness. Reports with more complete data receive higher confidence ratings and more granular AI analysis.

+60

Base confidence (always present)

Geocoding + FEMA zone + basic crime

+8

FEMA historical events data

Specific flood event record found

+12

Full permit history (1+ records)

County permit records available

+8

Year-over-year crime trend

FBI UCR historical comparison available

+7

Last sale date on record

Recorder deed transfer data confirmed

+5

Full FEMA + permit + school data

All primary sources returned real data

High Confidence (90–98%)
Moderate-High (75–89%)
Moderate (60–74%)
Data Limited (<60%)

AI Analysis Disclaimer

BeforeYouBuy Homes narratives are generated from structured property data using a template-based language engine — not a live large language model. They are designed to help buyers understand complex data — not to replace professional judgment.

DOMI Scores and AI recommendations are informational only and do not constitute professional real estate advice, legal advice, financial advice, or insurance advice. Scores reflect publicly available data at the time of report generation and may not reflect conditions at the specific parcel level.

Always consult licensed professionals — a certified home inspector, real estate attorney, licensed insurance agent, and a qualified real estate agent — before making any property purchase decision.

BeforeYouBuy Homes is not affiliated with FEMA, HUD, or any government agency. DOMI Score™ is a proprietary BeforeYouBuy Homes metric and trademark.