If you have even decent skills, there is no comparison of the economics.
Energy Saving projects are generally a marginal effort and the returns are over long periods of time.
For example, I estimate that sealing, improving soffit ventilation, sealing my Air Handler in the attic, and the basement sill plates will, at most, save $75-$100 per month. Granted my house is not a energy basket case, but there are deficiencies. For example, the attic has an air handler with no insulation and maybe 4 inches of Fiberglas. No Sealing and very deficient ventilation. The one hard estimate I have is $600 to cut 20 holes in muy soffite. Mind you this is just to cut and install grates, not to handle the inside part of that job. I’m guessing a contractor will charge $3 per square foot to insulate 10-12 inches of blown cellulose, a $4,000 expense. Not sure about sealing and soffit baffles.
My investment will be about :
$200 in the basement for calk and Poly ISO board.
$2,00o in the attic for sealing, air handler insulation (plus mastic and tape), cutting soffit holes, installing baffles, probably 20 cans of Great Stuff and 1350 square feet of 10-12 inches of blown cellulose.
$250 for Home made storm windows out of acrylic.
So let’s say $2,500 in total expense. a 2 year payback period.
Now, to pay someone to do all of this I’m guessing $7,000. A 6 year payback period
2/3 less ROI.
And this return is on the highest roi things I can do on the house.
If I move down the list of maximum benefit projects, quickly, paying someone else to do the work will be a net loss. Especially when you consider the life expectancy of some of the improvements.
To me, it’s easy to see how many energy improvements are not worth the expense when you pay someone else to do it. At some point, they are not worth your doing either, but that comes along much later in the project list.
so, the ROI for me doing it is (At $100/month) about 50%