A home's build year narrows down what's likely behind its walls. Lead paint was banned for residential use in the US in 1978; asbestos was common in flooring and insulation into the mid-1980s; polybutylene supply pipe was installed from roughly 1978 to 1996; aluminium branch wiring belongs to 1965–1974; and arc-fault protection wasn't required in bedrooms until the early 2000s. None of these are findings about a specific house — they are possibilities based on when it was built, and each one can be confirmed or ruled out without a professional.
Below is every construction-era issue we track, with the years it applies to and how to check it yourself. Nobody has looked at your house — including us. That's the point: these tell you what to look for.
Lead paint, Asbestos, Aluminium wiring, and 7 more
10 things to check
1970s
Lead paint, Asbestos, Aluminium wiring, and 6 more
9 things to check
1980s
Asbestos, Polybutylene pipe, Panel brand, and 4 more
7 things to check
1990s
Polybutylene pipe, Panel brand, No arc-fault protection, and 2 more
5 things to check
2000 onwards
No arc-fault protection, R-22 refrigerant
2 things to check
Every era issue, and how to check it
Before 1978Get it confirmed
Lead paint is likely under later coats
Lead-based paint was banned for residential use in the US in 1978. In homes built before then it's usually still there, sealed under newer layers — which is fine until sanding, scraping or a renovation disturbs it.
How to check it yourself: Swab kits from a hardware store are cheap and reliable enough for a first answer. Never dry-sand old paint before you know.
Who settles it: Certified lead-safe renovator, before any work on old paint
Before 1985Get it confirmed
Asbestos may be in flooring, insulation or duct wrap
Common in vinyl floor tile, pipe and duct insulation, textured ceilings and roofing into the early 1980s. Undisturbed and intact, it is generally left alone — the risk comes from cutting, drilling or demolition.
How to check it yourself: You cannot identify it by eye. Assume 9x9 inch floor tiles and papery duct wrap are suspect until tested.
Who settles it: Licensed asbestos inspector, before renovating or removing anything suspect
Before 1950Get it confirmed
Knob-and-tube wiring may remain in unrenovated areas
Original wiring in many pre-war homes. It has no ground, its insulation embrittles with age, and it overheats when buried in modern blown-in insulation — which is exactly where it usually ends up.
How to check it yourself: Look in the attic and basement for ceramic knobs and single cloth-covered conductors running through joists.
Who settles it: Licensed electrician
1965–1974Get it confirmed
Branch-circuit aluminium wiring is possible
Widely used for household circuits during a copper shortage in that decade. It expands and contracts more than copper, so connections loosen over time and can overheat at outlets and switches. It's a known fire-risk issue insurers ask about.
How to check it yourself: Pull an outlet cover and look at the cable jacket — it's often printed AL or ALUMINUM. Do not pull the outlet itself.
Who settles it: Licensed electrician — the fix is usually approved connectors, not a rewire
1978–1996Get it confirmed
Polybutylene supply lines are possible
Grey, flexible plastic pipe used for water supply into the mid-90s. It degrades from the inside where it meets chlorinated water and fails without warning — usually at a fitting, usually while nobody is home. Many insurers won't write a policy on it.
How to check it yourself: Look at the pipe entering the water heater and at the main shutoff. Grey, dull, about the diameter of your thumb, stamped PB2110.
Who settles it: Licensed plumber
1950–1990Quick to check
Worth checking the brand on your electrical panel
Federal Pacific Electric (Stab-Lok) and Zinsco panels were installed widely through this period. Both have a documented history of breakers that fail to trip under fault — the one job a breaker has. Insurers increasingly refuse or surcharge them.
How to check it yourself: The brand is printed on the panel door or the label inside it. You're looking for the words Federal Pacific, Stab-Lok, Zinsco or Sylvania-Zinsco.
Who settles it: Licensed electrician if it's either brand — replacement is the usual answer
Before 1965Worth knowing
Galvanised steel supply pipe may still be in place
Steel pipe corrodes and scales from the inside over decades, which shows up as falling pressure, discoloured water after a holiday, and eventually pinhole leaks. Typical service life has usually been exceeded by now.
How to check it yourself: A fridge magnet sticks to galvanised steel and won't stick to copper or plastic. Try it at the shutoff.
Who settles it: Licensed plumber
Before 1980Worth knowing
Cast iron drain lines are near the end of their life
Cast iron waste pipe typically lasts 50 to 80 years. Past that it corrodes from the inside and cracks, often under a slab where nothing shows until a floor is wet or the yard smells.
How to check it yourself: A plumber's camera scope runs a couple of hundred dollars and settles it completely. Worth doing once at this age.
AFCI breakers, which cut power when they detect the kind of arcing that starts fires, weren't required in bedrooms until the early 2000s. Retrofitting is one of the cheapest safety upgrades available to an older house.
How to check it yourself: Look at the breakers in your panel — AFCI ones have a test button and are labelled.
Who settles it: Licensed electrician
Before 1992Worth knowing
Windows may be single-pane or first-generation double
Beyond the heating and cooling cost, failed seals in early double-glazing show as permanent fog between the panes. Replacement is a large expense that rewards planning rather than reacting.
How to check it yourself: Hold a flame near the glass at night: two reflections means single pane, four means double.
Before 2006Worth knowing
R-22 refrigerant, if the AC is original
Air conditioning made before the mid-2000s generally runs on R-22, which has been phased out of production. Any repair needing a recharge is now expensive and getting more so, which changes the repair-or-replace maths well before the unit actually dies.
How to check it yourself: The refrigerant type is on the data plate of the outdoor condenser.
Which of these apply to your house?
Give HomePro your address and it pulls the county record, the building permits and the build year — then tells you which of these apply, and what the permits already rule out.
