7 questions to ask before buying a home built before 1980, according to inspectors

Older homes have a certain pull. The plaster walls, the solid hardwood floors, the character that newer builds just cannot fake. Still, homes built before 1980 carry a specific set of risks that many buyers do not think to ask about until an inspector points them out during a walkthrough.

Inspectors who work regularly with pre-1980 housing say the same handful of concerns come up again and again, from outdated wiring to hidden fuel tanks buried in the backyard. Asking the right questions before you sign anything can save you tens of thousands of dollars and a lot of stress down the road.

1. Does the home likely contain lead-based paint?

Lead paint is probably the most well-known hazard tied to older housing, and for good reason. The United States banned lead-based paint in housing in 1978, but a significant amount of homes built before then may contain lead paint.

The risk climbs the further back the construction date goes, since about half of homes built before 1978 have lead-based paint, and two out of three homes built between 1940 and 1960 have it, while nine out of ten homes built before 1940 have lead-based paint. What surprises a lot of buyers is that the risk does not vanish the moment the calendar flips to 1979.

Because lead paint might have been used in homes built as late as the mid-1990s, buyers with young children or pregnant family members might consider testing homes built even into the early 1980s rather than treating 1978 as a hard cutoff. Ask the seller whether any testing has been done, and if not, budget for a certified lead inspection, especially if you plan to renovate windows, trim, or doors, which tend to hold the highest concentrations.

2. Is there knob-and-tube wiring anywhere in the house?

Knob-and-tube wiring was standard practice for decades and is not automatically dangerous just because it is old. Even so, found in many homes built before the 1950s, knob and tube wiring lacks a ground wire, so excess electrical current has nowhere safe to go, raising the risk of overheating, sparking, and fire.

Some installations date later than most people assume, since it was last used in the 1950s with some reports of it being used up until the 1970s. The bigger issue for buyers is often insurance rather than the wiring itself.

If you keep the old wiring and find an insurer to cover you, expect to pay between 50% and 100% more per year for insurance coverage than an updated home with modern electrical components due to the high underwriting risk. Ask directly whether the electrical system has been updated, and if it has not, get a licensed electrician's assessment before closing so you know what a rewiring project would actually cost.

3. What material are the original water supply pipes made from?

Plumbing in older homes is a mixed bag, and galvanized steel pipe is one of the most common finds. Between the 1920s and 1960s, galvanized pipes were used in construction as a replacement for lead pipes, and in addition to eliminating that health hazard, they were more affordable, more durable, and easier to install than the alternatives available at the time.

The catch is that this material was never meant to last forever. Most estimates put the useful life of these pipes at 40 to 60 years, meaning homes built before the 1970s likely have pipes at or past end-of-life.

As they age, corrosion allows lead from the zinc coating to leach into drinking water, and prolonged exposure can lead to serious health problems, including developmental delays in children, cardiovascular issues, and kidney damage in adults. Ask for a plumbing inspection that specifically checks pipe material and condition, not just whether the faucets run.

4. Could asbestos be present in the insulation, flooring, or siding?

Asbestos shows up in more places than most buyers expect. Asbestos is most often found in homes built before 1980, including in popcorn ceilings, vinyl floor tiles, pipe insulation, attic insulation, drywall joint compound and cement siding.

Usage peaked well before regulators stepped in, with asbestos used in U.S. home construction from the early 1900s through the late 1980s, with peak usage between the 1950s and 1970s, before the EPA began restricting its use in 1973 and finalized a chrysotile asbestos ban in March 2024. The good news is that intact asbestos is not necessarily an emergency.

Problems arise mainly during renovation, since drilling into drywall containing asbestos will release fibers into the air, and drywall joint compound in homes built before 1980 commonly contained asbestos. Ask whether any materials have been tested, and if you are planning to remodel, budget for professional sampling before any demolition begins rather than after.

5. Is there a buried oil tank anywhere on the property?

This is one question many buyers never think to ask, yet it can be one of the costliest surprises in an older home purchase. Before natural gas lines, Americans heated and energized their homes with oil, and from the 1930s to the 1980s, tanks commonly stored this oil, with many homeowners burying them because they were prone to theft and unsightly.

Many of these tanks were simply left in the ground when heating systems changed. The liability tied to a leaking tank can follow the property rather than the person who caused the problem.

Environmental liability runs with the property, so if you buy a house with an unremediated buried tank and contamination is later discovered, you become the responsible party, even if the tank was installed decades before you bought it. Look for telltale clues like old fill or vent pipes sticking out of the ground near the house, or a petroleum odor or stained soil in the yard, and ask the seller directly whether the home ever used oil heat.

6. What condition are the sewer and drain lines in?

Underground plumbing rarely gets attention during a casual walkthrough, but it is one of the most expensive systems to replace once it fails. Homes from this era were commonly built with cast iron, clay, or Orangeburg pipe for their sewer laterals, materials that were durable for their time but were never designed to last a century.

Cast iron corrodes from the inside out and eventually develops holes, while clay and Orangeburg pipe are prone to cracking and root intrusion from nearby trees. A standard home inspection typically does not include a camera scope of the sewer line, which means a serious problem can go unnoticed until the line backs up.

Ask whether a sewer scope inspection has ever been performed, and if not, consider hiring a plumber to run a camera through the line before you finalize the purchase. Replacing a full sewer lateral can run into the tens of thousands of dollars depending on length and how much of the yard or driveway needs to be dug up.

7. Are there signs of foundation settling or long-term drainage problems?

Foundations in homes built before 1980 have had decades to react to soil movement, moisture, and freeze-thaw cycles, so some settling is almost expected. The real question is whether that settling has stabilized or whether it is ongoing.

Look for hairline versus stair-step cracks in masonry, doors and windows that stick or no longer close flush, and sloping floors, since these can all point toward differential settlement rather than simple cosmetic aging. Drainage issues often compound foundation problems in older homes, particularly if gutters, downspouts, and grading have not been updated in years.

Standing water near the foundation after rain, damp basement walls, or a musty crawlspace smell are all worth asking about directly. A structural engineer's evaluation is worth the cost if a general inspector flags anything beyond minor, stable cracking, since foundation repair costs can vary enormously depending on the cause and extent of the damage.

None of these seven questions are meant to scare buyers away from older homes. Many pre-1980 properties are perfectly livable and even highly desirable once the major systems have been updated or properly documented.

The goal is simply to walk into the purchase with eyes open, armed with the right questions, so that the charm of an older home does not come with an unpleasant financial surprise a few years down the line. A thorough inspection, paired with specialty testing where warranted, gives buyers real leverage in negotiations and peace of mind after closing.

Older homes were built to last, and with the right due diligence, they can keep doing exactly that for another fifty years or more.