Drumma -
It's hard to say. There's two different projects in play here; there's a complete gut and reinsulation/redrywalling of my living room, which ran about $5-7.5k and doesn't really have a payoff except for all the leaks, mold issues, bug eaten areas, and other stench I fixed.

For instance: See that metal strip running below the clerestory windows? That's a piece of flashing that runs from behind the siding to the roof deck. You could see daylight in it, and rain was getting driven back up beneath it.
The back-of-house windows and doors were $2500. Siding, trim, housewrap, sheathing, insulation, paint was $1000, give or take -- I lost track since we ended up adding some stuff, had to re-roof part of the house, etc. The labor was as free as I am.

Call it $4k for the entire project, and it took me about three weekends.


So far, my electric bill is down by $80 compared to this month last year, and it's actually been warmer than last year. We'll average that and say I'll get six months of benefits from it, so that's $480 a year between my electric bill and my gas bill. For a $10k job, that's a 20 year payoff. However, I also got a discount on my homewowner's insurance by replacing the wood siding with Hardi (and adding hard-wired smoke alarms throughout), and that totals another $100/yr. The value of the house EASILY went up by $5k from the work I've done; probably quite a bit more, and the standard of living increase from not having to hear my !@#$ing neighbor's dog barking all night thanks to the additional sound absorbing properties of the dual-paned windows is PRICELESS.