A home's age tells you what was available when it was built, and nothing more. Plenty of 1940s houses were rewired decades ago and plenty of 1990s houses have a problem nobody expected. Use this table the way a careful buyer does: to know which questions are worth asking about a home of this vintage, then go and look.
| Material | Roughly when | How you spot it | Why a buyer cares | What it costs to deal with |
|---|---|---|---|---|
| Knob-and-tube wiringElectrical Full guide → | Before roughly 1950 | Single wires running through white ceramic knobs and tubes in the attic or basement, and two-prong outlets throughout. | No ground wire, insulation grows brittle, and it is dangerous when buried under modern attic insulation. Many insurers will not write or renew a policy on a home with active knob-and-tube. | $10,000 to $25,000 to rewire a typical GTA house (smaller homes from ~$8,000; large heritage $35,000+) |
| Aluminum branch wiringElectrical Full guide → | Roughly 1965 to 1973 | AL or ALUMINUM stamped on the cable sheathing, and sometimes warm or discoloured switch plates. | A recognised fire risk at the connections rather than in the wire itself, which is why pigtailing the connections is the usual remedy rather than a full rewire. | $50 to $100 per connection; $2,000 to $5,000 typical whole-home pigtail (full rewire $8,000 to $15,000+) |
| Federal Pacific and Zinsco panelsElectrical Full guide → | Installed heavily from the 1950s through the early 1980s | The brand name on the panel door. Federal Pacific was also sold as GTE-Sylvania. | Breakers that may not trip reliably under load. Note there was never a recall, so the absence of one is not reassurance. | $1,500 to $4,000 to replace the panel (plus utility disconnect + permit; more with a service upgrade) |
| 60 amp electrical serviceElectrical Full guide → | Common in older homes, alongside 100 amp, before 200 amp became the modern standard | The number stamped on the main breaker or main fuse block. | Often not enough for a modern household, and 60 amp service is frequently an insurance problem in its own right. | $2,000 to $4,000+ to upgrade to 200-amp service |
| Galvanized steel supply pipePlumbing Full guide → | Standard in homes built before roughly 1960 | Dull grey threaded pipe. A fridge magnet sticks to it, which is the quickest test there is. | Rusts and narrows from the inside, so pressure drops and discoloured water follows. Replacement is a repipe, not a repair. | $6,000 to $15,000 to repipe (partial fixes possible) |
| Lead service linePlumbing Full guide → | Homes built before the mid 1950s to 1960s | A dull grey pipe entering the house at the water meter, soft enough to scratch, and no magnet attraction. | A drinking water health issue. Health Canada lowered its guideline for lead in drinking water to 0.005 mg/L in 2019 with guidance to keep levels as low as reasonably achievable. | $2,000 to $8,000+ to replace (sometimes cost-shared with the city) |
| Cast iron drainsPlumbing Full guide → | In homes built before roughly 1975 | Heavy dark pipes carrying waste out of the house, usually visible in the basement. | Corrodes from the inside over decades. A scope is the only way to know what the inside looks like. | Spot repairs from ~$500; main stack $2,000 to $6,000+; under-slab $5,000 to $15,000+ |
| Polybutylene, poly-BPlumbing Full guide → | Most commonly 1978 to about 1997 | Dull grey flexible pipe, often with a stamped code, usually visible at the water heater or under sinks. | The material and its fittings became a known failure and insurance problem, and some insurers now decline or surcharge homes that still have it. | $6,000 to $18,000 to repipe a house (Metro Vancouver often $10,000 to $20,000) |
| KitecPlumbing Full guide → | Roughly 1995 to 2007 | Orange and blue plastic pipe with brass fittings, common in condos as well as houses. | Subject to a class action settlement and a well known fitting failure. Frequently a condo issue, so check the status certificate as well as the unit. | $5,000 to $15,000+ to repipe a condo; $25,000+ for a large home |
| Lead paintHealth and safety Full guide → | Canada limited lead in interior paint in 1976, so mainly homes built before about 1980 | Not visible. It is under later coats, and it matters most where paint is chipping or where you plan to sand. | A health risk that matters most for young children and during pregnancy, and it changes how renovation work has to be done rather than being a reason not to buy. | Test kit ~$20 to $40; lead-safe reno work and removal add cost; abatement $1,000s+ |
| Asbestos containing materialsHealth and safety Full guide → | Used in building materials until roughly the 1980s to 1990s | Nine inch floor tile, wrapped pipe insulation, textured ceilings and some cement board. | Only a risk when disturbed. It is a renovation and abatement cost question rather than a live in it question. | Testing modest; small jobs ~$1,000 to $3,000; major abatement $10,000 to $30,000+ |
| Vermiculite, ZonoliteInsulation Full guide → | Poured into attics and sometimes wall cavities into the 1990s | Loose grey brown pebbly insulation in the attic that looks like small accordion flakes. | Vermiculite from the Libby mine may contain asbestos. Health Canada advises leaving it undisturbed and not entering the attic space. | Assume asbestos; professional removal commonly $10,000 to $30,000+ |
| UFFI, urea formaldehyde foam insulationInsulation Full guide → | Installed mainly in the late 1970s, banned in Canada in 1980 | Not visible. It shows up on disclosure forms and in older insurance records more often than in a viewing. | The ban shaped decades of buyer anxiety, though the current view of the risk in place is much calmer than it was. It still comes up on paperwork. | Removal is costly and rarely required; the main impact is disclosure and resale |
| Popcorn and textured ceilingsInterior Full guide → | Built between roughly 1950 and 1990 | Sprayed, stippled or knockdown texture, usually on ceilings. | On a pre-1990 home, test before you scrape. Otherwise it is a cosmetic item with an ordinary cosmetic price. | $2 to $4 per sq ft to remove; $8 to $15 per sq ft if it tests positive for asbestos |
| Oil heating and buried tanksHeating Full guide → | Common before the spread of natural gas, and still in use in parts of Atlantic Canada and rural areas | A tank in the basement, or fill and vent pipes coming out of the ground outside. | Tank age and location drive both insurance and environmental exposure, and a buried tank is the version that needs answering before you are firm. | Replace aboveground ~$2,500 to $5,000; a leak/contamination $10,000 to $100,000+ |
| Single pane and bare aluminum windowsWindows Full guide → | Standard before the 1990s, and used in builder grade homes into the 2000s | One layer of glass, or metal frames that sweat and ice up in winter. | A comfort and energy cost rather than a hazard, but a whole house of them is a large predictable expense. | $800 to $1,500 per window installed, more for larger or custom sizes |
Year ranges are drawn from the sourced guides in this library, each of which carries its own citations. Where a range is genuinely contested or varies by region, the table says roughly rather than picking a year. Costs are Canadian estimates that vary by home, region and contractor. Last reviewed 2026-07-21.
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