Home>Discussions>INSULATION & HVAC>Is it worth the cost to increase insulation when re-siding home?
4 posts / 0 new
Last post
Is it worth the cost to increase insulation when re-siding home?

We have a house in the Seattle area built in 1977. The house has R-16 insulation and is cedar-sided tongue and groove w/ old aluminum windows. We are planning on replacing the siding due to some dry rot and upgrading windows to Millgard aluminum. We are considering attaching R-10 rigid insulation to the plywood (to increase r-factor), prior to putting on the cedar siding. The incremental cost is substantial $5,500, for 1000 square feet, as new window sills will need to be fitted and drywall will need to be repaired. We are 100% electric and have a heat pump and our annual bill is $1,500. To reinsulated the entire house would cost roughly $15,000. Is it worth it ? The roof will need repairs in the next 5-10 years, would it be better to save and better insulate that? Any advice on how to value this would be greatly appreciated!

Re: Is it worth the cost to increase insulation when re-siding home?

I am not sure if I can answer whether or not the insulation cost will pay off over how long you are going to be in the home, but I can tell you that good windows and houswrap will. We added on to our 1988 modular two years ago. In the process, the contractor wanted to replace all the vinyl siding so that the siding would line up well and be of the same color (no fading). We agreed, but since we were ripping off all the siding, we took the house (which has R-19 insulated exterior walls), and replaced all the cheap and rotting double pane windows PLUS put on houswrap. We then put on new vinyl siding. We used Andersen 200 Series windows with low-E glass.

No new insulation was added.

In the end, we went from 1000 to 1500+ square feet of house (50% increase) and our electrical consumption went down a little bit ( we have baseboard electric heat). For me there is no really break-even date because I was going to have to change the windows anyhow, but it really did pay off to do the houeswrap (TYVEK).

GOOD Luck, and GO COUGS!

Timothy Miller
Re: Is it worth the cost to increase insulation when re-siding home?

Howdy 15,000 is a whole bunch for insulation what is being considered? Stopping air infiltration would be my first choice with the better windows and adding house wrap. caulking etc. What additional R value is the insulation you are considering? I would consider having a home energy audit to see what they recommend you do , consider contacting your utility co. for some references. I would have a air test to see how leaky the house is and getting their suggestions as to what to do to tighten it up.
I would think you would have a better return by adding insulation to the attic verses 15,000 to walls. Adding wall insulation to create a thermo block from the framing members to the outside siding but fist i'd get detailed projection of when the 15000 is recouped by decrease energy usage costs. Have you checked to see if your state is offering any help in offsetting the costs?

Re: Is it worth the cost to increase insulation when re-siding home?

Thanks to all 3 of you for the responses. After further investigation we feel the biggest heat loss is probably the roof so we are going to stick with new paper, siding and windows and save the insulation costs to put towards repairs and improving the insulation on the flat roof.

Sponsored Stories

TV Listings

Find TV listings for This Old House and Ask This Old House in your area.