Reference

Code-era risk guide

Building codes change over time, and homes built before a given change aren't required to meet it retroactively — that's how grandfathering works. These are the code-era factors Tarn checks automatically when you search an address with a year built. Each one below explains what it is, why it matters, and what's typically worth doing about it.

Health

Lead Paint in Homes Built Before 1978

Homes built before 1978 are presumed by federal law to contain lead-based paint somewhere in the home, unless testing shows otherwise.

Built before 1978
Plumbing

Polybutylene Pipe in Homes Built 1978–1995

Homes built between 1978 and 1995 may have polybutylene (PB) water supply pipe — a plastic pipe material at the center of a large class-action settlement over fitting failures.

Built 1978–1995
Electrical

Older Electrical Panels in Homes Built Before 1990

Homes built before 1990 without a documented panel upgrade may still have their original electrical panel, including brands like Federal Pacific (FPE Stab-Lok) or Zinsco that have a documented history of breaker failures.

Built before 1990
Electrical

Aluminum Branch Wiring in Homes Built 1965–1973

Homes built between 1965 and 1973 may have aluminum branch-circuit wiring instead of copper — a material with a documented higher fire risk at its connections.

Built 1965–1973
Electrical

Knob-and-Tube Wiring in Homes Built Before 1950

Homes built before 1950 without a documented rewire may still have some of their original knob-and-tube wiring — an ungrounded system that most insurers won't cover.

Built before 1950
Life safety

Smoke Alarm Interconnection in Homes Built Before 1993

Homes built before 1993 without a later electrical update may have standalone smoke alarms instead of interconnected ones — meaning an alarm in one room won't necessarily trigger alarms elsewhere in the home.

Built before 1993
Structural

Deck Lateral Load Anchoring in Decks Built Before 2015

Decks permitted before 2015 may be attached to the house with ledger bolts alone, without the lateral-load anchoring more recent code requires — a factor in most deck collapses.

Deck permit before 2015
Plumbing

Water Heater Age Beyond Typical Lifespan

If the most recent water heater permit on file is 25 or more years old, the unit is likely well past its typical 15-year service life, and its pressure-relief valve's condition is uncertain from records alone.

Most recent water heater permit 25+ years old

Check these against a specific address

Enter an address and the year it was built, and Tarn runs it against every factor above automatically.

Search an address