Insulating a Home Built Before 1980: What Spokane Homeowners Need to Know

Do homes built before 1980 have insulation in the walls?

Often very little. Many homes built before 1980 have uninsulated or barely insulated walls, because energy codes were weak or did not exist yet. You usually cannot see it without checking, but the signs show up in cold walls, high bills, and rooms that never feel even. Injection foam lets you insulate those existing walls without tearing them open.

Why so many Spokane and Coeur d'Alene homes were built without wall insulation

Walk through almost any established Spokane neighborhood, the South Hill, Garland, Shadle, West Central, or head across the state line into older parts of Coeur d'Alene and Post Falls, and you are looking at homes built in an era when insulation was an afterthought.

Energy was cheap. Nobody was thinking about R-value. Washington did not adopt a statewide energy code until the late 1970s, and Idaho followed later still. Before that, whether your walls got insulated came down to the builder, the budget, and the year.

So the house you are living in was very likely built to a standard that assumed you would just burn more fuel when it got cold. That worked fine in 1958. It does not work at all when you are looking at a January heating bill in a house on the South Hill with a north-facing living room that never gets above 66 degrees.

What is probably inside your walls right now

Here is the rough picture by era. Yours may differ, but this is what we find most often in Inland Northwest homes.

For comparison, current guidance from ENERGY STAR for our climate zone puts exterior walls at roughly R-13 to R-21 and attics at roughly R-49 to R-60. If your home was built in 1962 and still has its original walls, you are running at a fraction of that, every hour of every winter.

The four places an older Inland Northwest home leaks the most

Insulation is only half the story. Older homes lose energy through a combination of missing insulation and open air paths. In the homes we work on, these four spots do the most damage.

1. Exterior wall cavities. The biggest single surface area in your home, and in a pre-1980 house it is often hollow. Air moves freely inside the cavity, carrying heat up and out.
2. The attic floor. Original attic insulation settles and compresses over decades. Four inches of 1960s rock wool that has flattened to two is doing almost nothing.
3. Top plates and wall penetrations. Every spot where a wire, pipe, or duct passes through framing is a small chimney. Add up a few dozen and you have a hole the size of a window, open all winter.
4. Rim joists and band boards. The strip of framing where your floor meets the foundation. Rarely insulated in older construction, and it sits right at the coldest part of the house.

That combination is why an old home can feel drafty even after you replace the windows. Windows are usually a smaller share of the loss than people assume. The walls and the air leaks are where the money goes.

You do not have to tear out drywall or plaster

This is the objection we hear most, and it is the reason a lot of homeowners put this off for years. They assume insulating existing walls means gutting rooms, patching plaster, and repainting the whole house.

It does not, and that is exactly what injection foam was built for.

Injection foam is a slow-expanding foam pumped into your existing closed wall cavities through small access holes. The crew works from the outside in most cases, removing a course of siding or drilling through it, filling each cavity from the bottom up, then plugging and patching the holes and putting the siding back. The foam flows around wiring, pipes, and blocking, then cures in place.

What that means for you:

• No drywall removal, no plaster repair, no repainting interior rooms
• No moving out, and usually no moving furniture
• Most homes finish in a single day
• The foam air-seals as it fills, so you get insulation and draft control in one step

For a home with plaster and lath walls, which a lot of pre-1940 Spokane houses have, this is a very big deal. Plaster repair is expensive and slow. Working from the exterior sidesteps it entirely.

What the process actually looks like on an older home

1. Assessment. Someone comes out, checks what is already in your walls and attic, measures square footage, looks at siding type and access, and identifies any conditions that need attention first.
2. Scope and quote. You get a written number for the work, usually broken out by walls, attic, and air sealing so you can decide what to do now and what can wait.
3. Install day. Access holes, fill, plug, patch, and reinstall siding. Attic work happens the same day if it is part of the scope.
4. Cleanup and walkthrough. You should be able to look at the exterior afterward and not be able to tell where the holes were.

Things that come up specifically in older homes

Knob-and-tube wiring. If your home still has active knob-and-tube in the walls, it needs to be evaluated before any cavity gets filled. This is not a reason to give up on insulating. It is a reason to have it looked at first. Many older Spokane homes were rewired decades ago and only have abandoned knob-and-tube left behind.

Balloon framing. Common in homes built before roughly 1930. The wall cavities run continuously from the foundation to the attic with no fire blocking, which turns each one into a vertical air channel. Filling those cavities makes a dramatic comfort difference, and it needs an installer who knows to expect it.

Brick veneer or stucco. Both are workable. The access approach changes, and the patching matters more, so it is worth asking any contractor how they handle your specific exterior.

Previous partial work. A lot of older homes have had one attic top-off and nothing else. Adding more attic insulation on top of hollow walls is like putting a hat on and leaving your coat unbuttoned. Walls are usually where the remaining opportunity is.

What it actually changes

ENERGY STAR estimates that homeowners who air seal and insulate save an average of 15 percent on heating and cooling costs, or about 11 percent on total energy costs. Older, under-insulated homes tend to land at the higher end of that range, simply because they have further to climb.

But the number people notice first is not on the bill. It is that the back bedroom stops being 8 degrees colder than the hallway. It is that the furnace stops running in long cycles. It is that the wall behind the couch is no longer cold to the touch in February. Comfort shows up immediately. The savings show up on the bills that follow.

Frequently asked questions

Can you insulate the walls of an old house without removing drywall? Yes. Injection foam is pumped into existing closed wall cavities through small access holes, usually from the exterior. There is no drywall or plaster removal, no repainting, and most homes are finished in a day.

How do I know if my walls have insulation already? The quickest reliable answer comes from a professional assessment, which can include checking at an outlet or a small inspection point. Cold interior walls, uneven room temperatures, and high heating bills in a pre-1980 home are strong indicators that the walls are empty or underfilled.

Is it worth insulating a house from the 1950s or 1960s? Usually yes, and often more than a newer home. Older homes start from a much lower baseline, so the improvement in both comfort and bills is bigger. The walls of a 1950s home are typically the single largest untapped opportunity in the house.

Will insulating an old house cause moisture problems? Properly installed insulation with appropriate air sealing generally improves moisture performance, because it reduces the warm humid air moving into cold cavities where it can condense. Existing moisture issues, like a leaking roof or an unvented crawl space, should be corrected first. A good assessment catches these before any work starts.

Do I need to insulate the attic and the walls, or can I just do one? You can do one, and many homeowners phase the work. If your attic is already reasonably deep and your walls are empty, walls will usually give you the bigger jump in comfort. If both are thin, doing them together is the most cost-effective way to fix the envelope.

How long does it take to insulate an older home? Most single-family homes in the Spokane and Coeur d'Alene area are completed in one day. Larger or more complex homes can run into a second day.

Ready to find out what is in your walls?

If your home was built before 1980, you do not have to guess. We will come out, look at your walls and attic, tell you exactly what is there, and give you a straight number for fixing it. No cost, no pressure.

Get your free older-home insulation assessment

USA Insulation of Spokane and Coeur d'Alene | 509-862-5655