Re: Replacement Windows vs. Blown In Insulation
Both are equally important as far as improving the insulating performance .... however .... installing insulation into the walls and replacing all your windows at the same time would be ideal but expensive to do in one shot. Unless you have won a lottery or have the key to Fort Knox then it's more reasonable to pick one to do first and at a later time budget for upgrading the other.
Having said that here's my opinion.....
The walls would be the first thing to tackle since they cover more surface area and would be the largest point of heat loss in colder seasons and heat gain in the warmer seasons. Also consider improving the attic insulation at the same time.
The windows are another source of heat loss/gain as well as being drafty. The windows can be temporarily improved by caulking / spray foam in a can to seal around the frames . Also you might even carefully remove the interior frames and use the foam between the window frame and the wall structure to stop drafts..... providing there aren't sash weights.
The windows themselves can be covered over with plastic on the inside and a storm window on the exterior during the cold season.
These temporary steps will get you through till you can budget replacing windows .... perhaps doing one room at a time.
Just a thought.
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