How Almwell estimates component ages

Almwell estimates the age of your roof, HVAC system, water heater, and sewer lateral by combining several public data sources:

Property records

County assessor data includes the home's year built, square footage, roof material, and prior sale history. We use year built as the default install date for original systems when no better signal exists.

Permit history

Re-roofs, HVAC replacements, and water heater swaps typically pull building permits. Where permit records are digitized and accessible, Almwell reads the permit date as the system's install date — a much more accurate signal than year built.

Median replacement assumptions

For systems with no permit signal, we apply median lifespan assumptions by material and system type — the same ranges described in our Learn guides. These are starting estimates; homeowners can correct them with known dates once signed in.

Cost bands

Cost figures in our guides are 2026 national-average ranges from standard remodeling and maintenance sources. They are directional ranges, not Almwell's computed per-home estimates. Your actual cost depends on your region, home size, contractor, and specific conditions. Always pair a band with your Snapshot for a home-specific number.

• Figures are kept as ranges so they age gracefully as prices change.
• The dateModified on each article makes the year explicit.
• We do not present guide ranges as Almwell's computed estimates — see the distinction in each article.