Insulation Contractor in Napa, CA - Drafty Older Houses Sealed and Insulated
Evergreen Petaluma Spray Foam Insulation is an insulation contractor based in Petaluma, CA, insulating and air sealing attics, walls and crawl spaces in Napa for homeowners dealing with drafty rooms, hot upstairs bedrooms and cold floors.
- Licensed and fully insured.
- Free quotes on site.
- Expect a reply within 1 business day.
Insulation work in Napa's older houses
Napa is a mix of older houses close to downtown and the river and newer neighborhoods farther out, and our calls come from both. We come over from Petaluma the same way we head out to Sonoma, so Napa is part of our regular stretch of the map.
The older houses usually sit on raised floors over a crawl space, with attics holding a few inches of fill that went in decades ago, if anybody added any at all. The newer ones tend to have more up top but bring their own trouble, like the room over the garage that never feels right. That split decides most of the job, because an older house usually needs cleanup and sealing before anything new goes in, while a newer one is often about tracking down the one weak spot.
What we do on Napa houses
Attic insulation
Plenty of Napa attics are down to a few settled inches of old fill. We add blown-in loose fill, insulation sent through a hose, to an even depth across the attic.
Attic air sealing
Upstairs rooms that run hot usually trace back to gaps around can lights, pipes and the hatch. We seal those first, so new insulation isn't fighting a draft.
Insulation removal
Older Napa attics sometimes hold fill that got wet or filled with droppings. We vacuum it out and clean up, because new insulation laid over it keeps the problem.
Wall insulation
Lots of older Napa houses have hollow walls, so rooms stay drafty with the heat on. We blow wall insulation into them through small holes, then patch.
Crawl space insulation
Cold floors in older raised-floor houses usually mean a bare crawl space or batts that sagged down. We fit insulation snug under the floor and support it so it stays.
Spray foam insulation
Spray foam costs more, so in most attics I'd seal the gaps and top up the fill instead. When your ductwork lives up there, foam seals and insulates at once.
What Napa houses usually need first
Most of the older Napa houses I look at have had their attic worked on once or twice over the years, and not always in the right order. Somebody laid new fill over old fill that should have come out, buried the eave vents so the attic can't breathe, or piled it deep in the middle and thin at the edges, which is exactly backward. My dad taught me to go up into the attic and down into the crawl space before saying a word about price, so that's what I do, and if your house is in decent shape, I'll tell you it can wait.
What moves the price here is how much old material has to come out, how many gaps need sealing, how tight the attic or crawl space is to get into and whether loose fill or foam suits your house. The schedule turns on the same things, plus a permit if the city wants one for your job, and I'll see all of it when I come out to look and write your estimate.
Get a free on-site insulation estimate for your Napa house
Tell us what's going on with your Napa house, whether it's the drafty living room, the hot upstairs or the cold floors, and we'll reply within one business day. I come out myself to look at the job and write the estimate, free and with no obligation. If you'd rather talk it through, call (707) 238-6044.
Napa insulation questions, answered
Here's what Napa homeowners ask us most about permits, cost and getting back into the house. If your question isn't here, bring it up when I come out for the estimate.
Do I need a permit to insulate my attic in Napa, CA?
The city's permit lists don't name insulation either way, so I don't guess, and we check with the City of Napa Building Division before we start. When a permit is needed, we handle it, and if your job needs one but no plans, the city issues those over the counter, the same way it does for roofing or a water heater change-out.
How do I submit permit plans to the City of Napa online?
You can't, because the city has no online portal for submittals, so plans go in person to the Building Division counter, which is open to the public 8 AM to 4 PM Monday through Thursday. Plans for small projects that review quickly get looked at right there at the counter, according to the city's permits page, and when your job needs a permit, we're the ones who make that trip.
Which building codes apply to insulation work in Napa?
Any permit applied for in Napa since January 1, 2026 has to meet the 2025 California Codes, which the city enforces with its own local amendments. The city also says all work has to meet the codes and ordinances that apply, even work that needs no permit, so we do the job to code either way.
Is a City of Napa business license enough to trust an insulation contractor?
No, because the city says it issues business licenses for revenue purposes only, so the license is about the city's books, not a check on anyone's work. Ask who will actually be in your attic and whether they're insured, and for us the answer is that we're licensed and fully insured, I write the estimate, our crew lead and installers do the work, and I go over it with you at the end.
What makes insulation cost more on an older Napa house?
Usually it's old material that has to come out first and a lot of gaps that need sealing, the price drivers I covered above. On many older houses, sealing the attic and topping up the fill does most of the good for less than starting over, and I'll tell you if that's true of yours when you call (707) 238-6044 and I come out.
How long do we have to stay out of the house after insulation in Napa?
For air sealing and blown-in fill, you usually don't have to leave at all, because the crew works up in the attic and you just hear us thumping around overhead. Spray foam is different, since it comes with a re-entry time, the hours everyone stays out while the house airs out, so we go over that with you ahead of the day and you can plan for the kids and pets.
Insulation work up close
Other cities we work in
If your house isn't in Napa, look for your city here, or call (707) 238-6044 and ask whether we come out your way.