Adding insulation to an old house.

[Reynolds531]

I'm trying to decide whether or not to spend $1500 to $2000 and a ton of hours to optimistically cut $90 a year off my heating bill.

I live in a 1200sq ft single story house built in 1958. The attic, rim joists, air sealing and multiple small projects have all been done. My furnace is a 1989 Clare which my gas guy says isn't efficient but will thrive for years to come with no love. He said concentrate on insulation.

I estimate I burn $500 per year of natural gas for home heating. A new furnace will eventually lower that number. Variable rates and an ever increasing carbon tax will raise it. I have no plans to move.

Optimistically I will save about 20% by finishing my bare basement block foundation. Doing a cheap 4' hanging foundation blanket isn't really an option on blocks.

So question is....is this project worth tackling for the return I'm likely to get??

[ysette9]

I strongly favor insulation but the cost savings is a secondary reason. Living in an insulated house is just so much more comfortable. That is worth spending the money to me. In fact, we spent about $4k recently to have everything insulated in our house, including interior walls. I am very glad I did when I walk on the floors in winter without freezing cold feet and the toddler’s screams are muffled at night to not wake up the baby in the next room.

[mustachemountain]

air sealing first, its more important than insulation.
have you had a blower door test to see exactly how tight your house is?
the biggest bang for the buck in insulation is the attic (if you have one) for like $300 and a dirty day of work i rolled out 6" thick insulation and the difference summer and winter is astonishing.
the best insulating I've seen is outsulating: foam board is applied outside of the sheathing, and then sided over. that's a major renovation project though. it results in a continuous air barrier, and no thermal bridging thru the studs. you need to calculate the thickness of the foam to match your climate or you will get condensation, rot and mold in your sheathing.
batt insulation should NEVER be in contact with below grade walls/masonry of any kind. www.buildingscience.com has tons of great science applications.

[GuitarStv]

+1 on air sealing first.  A drafty house sucks.  A poorly insulated one you can just keep turning up the heat.

[Reynolds531]

Thanks guys. I've done pretty much all that. I didn't do a blower test, but I'm signed up for a free nest thermostat from Ontario. I think they do it for you then.

I did buy and extensively use a $2 smoke pencil. I couldn't believe all the gaps I found. I was caulking etc for days.

The plan in the basement is 2" foam then framing and r14 roxol. Still thinking. I did a better estimate and came up at $2200.

[mustachemountain]

a before and after blower door test is the best way to see how effective your air sealing efforts were. it costs money so i didn't do it either ha. the smoke pencil can find the big ones but trust me there are more.

an uninsulated foundation is constantly conducting heat out of your house. in Florida that's great, in Canada, not so much. that's why insulating and sealing the room joist is so crucial. a thermal break between the foundation and the framing is great for new construction but a major job to retrofit. ditto exterior foundation insulation. so you gotta do it from the inside. sounds like you've read up on it, but be sure you've addressed any potential moisture issues. also, frost heave is a tiny possibility in unheated basements. building science websight covers all of this stuff.

I'm not sure of the absolute $/¢ payoff of this work, but as mentioned before the comfort level of your house will increase, and your energy efficiency will go up. there's nothing wrong with saving the earth, especially if there aren't catastrophic financial penalties associated with it.

[pecunia]

A lot of heat loss is through windows.

https://www.energyguide.com/info/window2.asp

Cheap fix is styrofoam panels over the windows of any rooms you are not in.  Hold your hand against a styrofoam panel for a minute.  Hold your hand against a window for a minute.  Which was colder?

Depending on where you live, I've seen hay bales used around basement walls to preserve the heat.

Sealing it well will also prevent the entrance of unwanted vermin into the house. 

[Retire-Canada]

So question is....is this project worth tackling for the return I'm likely to get??

I asked myself the same question as my situation is similar in terms of cost/payback. I decided it just wasn't worth the hassle. My house is comfortable as is and the amount of $ I can save doesn't justify the investment in time and cost.

I'll focus my spare time on things I enjoy more and/or have a better payback.