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Blind spots by year

What to look for in a house built in 1979

A 1979 build is 47 years old. This sits in the polybutylene window, and poly B fails without warning rather than leaking slowly first. Here is what tends to be true at that age, what each one costs in 2026 Canadian dollars, and the sentence to say to the agent.

Three blind spots in a 1979 house

Ordered by what tends to matter most.

Worth knowing before you go firm

Polybutylene supply plumbing

Homes built between the mid 1970s and the late 1990s sit in the polybutylene window. Poly B is grey, smooth and flexible, it reacts with chlorine over the years, and it fails without warning rather than by leaking slowly first. That failure mode is why it comes up when a policy is arranged.

A whole house repipe runs $6,000 to $18,000, and $10,000 to $20,000 in Metro Vancouver.

Look at the pipe where it comes out of the wall at the water heater and under the kitchen sink. Poly B is usually grey, sometimes white, silver, black or blue, and often has PB or the word Poly stamped on it. One photo of each answers it.

Say this to the agentWhat are the supply pipes made of, and is there any poly B or galvanized left anywhere in the house?

The Federal Pacific and Zinsco panel era

Two panel brands from this period have a specific problem. Federal Pacific, sometimes badged Federal Pioneer or Stab Lok, has breakers that can fail to trip on an overload. Zinsco, common in homes built 1963 to 1981, has breakers that can fuse to the bus bar and not trip at all. Both are a replace rather than a repair.

Replacing the panel is $1,500 to $4,000, plus the Hydro disconnect and the ESA permit on top.

The brand is on a sticker inside the panel door. Federal Pacific breakers carry a small red stripe. Zinsco toggles are red, green and blue. One photo of the label and one of the breakers is enough.

Say this to the agentWhat brand is the panel, and what is the main breaker amperage?

The systems are 47 years old, if they are original

The building is 47 years old, and so is every system in it that has never been replaced. That is the part a listing photo cannot show you, because a replaced furnace and an original one look identical from the doorway.

  • The water heater lasts 8 to 12 years. An original one here is past that, and replacing it is $1,800 to $2,800, in Ontario if the tank is owned, and a great many Ontario tanks are rentals.
  • The air conditioner lasts 10 to 15 years. An original one here is past that, and replacing it is $4,500 to $9,000, in Ontario, or $3,500 to $6,500 if only the condenser is replaced.
  • The furnace lasts 15 to 25 years. An original one here is past that, and replacing it is $3,500 to $8,500, in Ontario, and $5,500 to $10,500 for a high efficiency unit.
  • The roof lasts 20 years for a 3 tab asphalt roof and about 30 for architectural shingles. An original one here is past that, and replacing it is $8,000 to $18,000, a GTA re-roof, more for steep or multi layer roofs.

All of these carry a date. The water heater has a rating plate near the top of the tank, usually with the date encoded in the serial number, and the furnace and the air conditioner both carry a dated label. Photograph them.

Say this to the agentHow old is the water heater, and is it owned or rented? Has the air conditioner been replaced, and if so when? How old is the furnace, and has the heat exchanger ever been checked? When was the roof last done, and is there paperwork for it?

Three more that come with a house this age

A lead water service line or lead solderWhat material is the water service line, and has the city replaced its side of it?
Era materials that can contain asbestosIs there any original pipe wrap, vinyl floor tile or textured ceiling left, and has any of it ever been tested?
UFFI, if this house was ever foam insulatedHas this house ever been tested for UFFI, and is there a declaration about it in the paperwork?

This is what is typical for the year. It is not a finding about this house.
Photographs of the panel, the basement and the water heater would tell you whether any of it applies here.

Worth ten minutes each

Is Poly B a Dealbreaker? Homes Insurers Will Not Cover in Canada FPE and Zinsco panels

Built from the Casaroo knowledge base in 2026. Ages on this page are counted to 2026.