I'm shocked and disappointed at how expensive retrofitting insulation into a minimally insulated 1930s Bay Area house actually is. I estimate gas heating costs at around 2500$ / year (nov-march), while insulating floors, walls and roof would cost a shocking 60K$ for an average size 3bdrm.
If the insulation cuts heating cost in half, that's a 1250$ savings per year, meaning a 48 year break even time assuming zero discount rate. It absolutely doesn't make sense to do the work unless there's a massive tax subsidy or contractor costs come down (which is bad for the environment)
@jpdaigle Clearly too many factors play into however you received that quote...But, maybe this can help you...
Years ago, i researched insulating my home...an old home that was split into 2 living portions...and whose front half/portion was built in late 1800s, and back portion of home was built around late 1910s. So, you can imagine it was pretty much a sieve, just burning our money. So, i did get a few costly quotes...but the cheap husband in me wondered if i can do things piecemeal....and i assure you that its possible. There are lots of factors to consider....but you can research and determine for yourself.
Here is my suggestion:
1. Contact your electric company/provider...and ask them if they offer a free energy assessment. Ours did, and it helped us determine the exact zones/sections of our home where we had the worse heat loss. This assessment was so valuable, i wold have paid to have this done!
2. Research where you/your family spend the most time in the home. My opinion is that the bedrooms should be the last places to insulate, since blankets (and bodies) help keep things warm in this type of room.
3. Consider which areas of the home can be insulated via easier methods - like spray foamy stuff - which may only need little holes and not necessary to tear down full walls, etc. Some of these foams are not as insulating as traditional options, but the ease and cost is more than enough to justify things.
4. Ideally start on the outside walls of the home, and of the specific rooms/area where you will focus your first work.
There is so much more on thios topic...but keeping the work low in scope, and iterative really can help...its all about being clever here. Good luck!!
Numbers don't look great but you would need to consider the following too.
Any cooling cost you have that will also benefit from insulation and the fact that within 10years time you most likely need to upgrade the gas heater with something non fossil.
Also it is questionable if gas prices will remain where they are currently.
You could prioritize insulating some areas instead of all of them. Attic is the most effective and easy to do since it is usually open. Walls are less effective but expensive to drill holes or open up walls. Floors or basement are least effective but easy.
That is what I did, insulating the attic but not getting around to the walls and basement.
Construction is incredibly expensive. Why that is complicated. In a lot of the ways the problems though is our lack of newer affordable homes. Newer homes tend to cost more and have all the tech. Older homes are cheaper but paying someone else to upgrade them is crazy expensive.
If the insulation cuts heating cost in half, that's a 1250$ savings per year, meaning a 48 year break even time assuming zero discount rate. It absolutely doesn't make sense to do the work unless there's a massive tax subsidy or contractor costs come down (which is bad for the environment)