Fill my house's walls with expanding foam insulation, or replace windows?

[NickB79]

I'm debating whether to tap the savings account in the spring to have the walls of our house insulated with spray foam, or to replace windows. Our walls are always ice cold in the winter in our 1968-built home, so there's pretty much no insulation in there. Plus, I can put my hand in front of an electrical outlet and just feel a blast of cold air coming in from outside when the wind blows!

At the same time, several of my windows are original: single-paned and some of the smaller panes are actually lose in the frames from the window pane caulking drying out and chipping away. I've put plastic window wrap over them, and I'm going to re-caulk them in the spring. The windows are so drafty, heavy blizzard storms can actually cause the plastic wrap to pop off unless I add extra tape to the frame.

We added a ton of blow-in insulation to the attic last year, so that's taken care of, and replaced a drafty old front door and patio door as well. It's down to either replacing windows or insulating walls at this point, and I'm wondering what would be more cost-effective.

[The Velveteen Ocelot]

1. I just had an energy audit done of my drafty old house.

The guy who did the audit told me that the most useful heat-preserving improvements are, in this order: 1. Insulate the attic. 2. Replace old windows. 3. Insulate the walls. I still need to insulate, but I just replaced six of my worst 100-year-old windows with new, triple-glazed, EnergyStar windows and I can already feel the difference. The house is less drafty and the windows don't rattle like they used to.

[NickB79]

2. Do you think the energy audit was worth it?

Our electric company sent out a guy to do what they call an energy audit, and it basically consisted of him walking through the house and telling us to change our bulbs to CFL's, even though we already had.

I've read that independent energy auditors are much more comprehensive. How much work did your auditor do?

Thanks!

[The Velveteen Ocelot]

4. This was a full audit, done by a contractor for the gas company.

It cost $100, but the gas company gave me a discount on my bill for having it done. The guy brought this huge fan that he stuck in my front door with a seal around it, and he used some instrument to measure the rate of air exchange, and then he went all over the house with an infrared sensor to see where the cold spots were, and also checked my furnace for CO2. He gave me a written report and a CD showing the results of the infrared tests, along with some weather-stripping, foam caulk and plastic seals to put in my electric outlets. So it was pretty thorough. I was not surprised to learn that my old house leaks like a sieve, though not so much now that I got those new windows.

[elleng]

3. Both

Friend replaced windows recently, walls still cold so thinking about/waiting to afford the foam in spring. Sorry, tho, can't say which more cost-effective for you now.

[femmocrat]

5. Not sure in your case, but I would recommend the windows.

We did our entire house a few years ago, and we love them. We had those Andersen double-hung windows and the glass was actually separating from the wooden frame. Most of them were cloudy between the panes of glass. They were terrible windows and only about 8-10 years old.

We got vinyl replacement windows and they are wonderful. Not only are they nice and snug, but they keep out most noise. I don't even hear our neighbor's dogs bark or vehicles going by. You won't regret replacing those drafty windows.