R26.5 vs. R20 walls

[JMWarren]

I'm looking at building a new home. The builder will face the walls 1" Rigid insulation for about $1150 which bumps the R-Value from 20 to 26.5

I'm in South Western Ontario, we get cold winters. Can anyone advise me if this is worth it?

Thanks!

 

[SSSnail]

I think this belongs in Highly Technical.

 

[Sphexi]

$1150 spread out over 30-40 years, I'd say it's worth it. Any and everything you can do to keep in that warmth is worth it.

 

[GagHalfrunt]

I'd put the extra money into ceiling or attic insulation before bumping up the walls.

 

[middlehead]

Originally posted by: GagHalfrunt
I'd put the extra money into ceiling or attic insulation before bumping up the walls.

Ding.

But yeah, $1200 now to make future savings on something you ought to be living in for many a year is a no-brainer.

 

[JMWarren]

I probably should have added that I probably won't be there for more than 5 years, so I'm not sure it will pay back in that time period. The Attics are already R55...

 

[RU482]

Are they using fiberglass batts to achieve R20? $1200 isn't too bad for the extra R value...unless the house is tiny...how large and what style of house?

Is this a common practice in your area?

 

[IHateMyJob2004]

Just do it.

 

[XZeroII]

All the celebrities go with R26.5. Why wouldn't you?

 

[XZeroII]

Seriously though, you're building a house that you're only going to live in for about 5 years? Why?

 

[JMWarren]

Originally posted by: redly1
Are they using fiberglass batts to achieve R20? $1200 isn't too bad for the extra R value...unless the house is tiny...how large and what style of house?

Is this a common practice in your area?

Yes, the walls are 2x6 and they are using fiberglass. Some homes also use rigid insulation, but usually over 2x4 walls. Only Energy Star homes have done both. The house is 2 Storys and about 1800 sq ft.

Originally posted by: XZeroII
Seriously though, you're building a house that you're only going to live in for about 5 years? Why?

It's at least $25,000 less to build new than it is to buy resale at this point in time in this area. Even if I sold it a year out I'd still make a nice profit.

 

[SearchMaster]

Originally posted by: JMWarren
I probably should have added that I probably won't be there for more than 5 years, so I'm not sure it will pay back in that time period. The Attics are already R55...

Then I wouldn't do it. It's doubtful that it will add to your resale ("kitchens and baths sell homes") and it won't pay for itself in 5 years or less.

 

[Vette73]

I would go for it. It is not only for the R factor but it also reduces noises as this will go on top of the stud, not inbetween. So it will be more quiet as well which will help resale the house. Juts take pictures to show it is there and point out, when you sale, how quiet it is. Its little things like that people will over look.


Also check to see if there are any power discount since it has that type and Rfactor of insulation from the power company?

 

[skyking]

Originally posted by: Marlin1975
I would go for it. It is not only for the R factor but it also reduces noises as this will go on top of the stud, not inbetween. So it will be more quiet as well which will help resale the house. Juts take pictures to show it is there and point out, when you sale, how quiet it is. Its little things like that people will over look.


Also check to see if there are any power discount since it has that type and Rfactor of insulation from the power company?

Good points, and chump change in the whole scheme of house building. Do it.

 

[sdifox]

Go for it, you can never have enough insulation. And doing it now is a lot cheaper than trying to retrofit.

Where are you located?

 

[Scarpozzi]

Might want to research compression of the insulation over the years. I have insulation in my ceilings that I caught a glimpse of last summer. Gravity has taken its toll...

That being said, you might want to look for an insulation solution that is going to totally SEAL the walls and worry more about air leaks than actual R factor. Then, in another 30-40 years, look into upgrading...that will take care of longevity.

I'd personally rather put that 1200 to use in getting better windows. They are where you REALLY lose heat in the winter.

 

[Nitemare]

Rigid insulation doesn't settle.
It would act as a sound dampener between you and the outside world
You would save a decent amount on heating
You live in Canada, it's cold there, Aye?

 

[sdifox]

Originally posted by: Scarpozzi
Might want to research compression of the insulation over the years. I have insulation in my ceilings that I caught a glimpse of last summer. Gravity has taken its toll...

That being said, you might want to look for an insulation solution that is going to totally SEAL the walls and worry more about air leaks than actual R factor. Then, in another 30-40 years, look into upgrading...that will take care of longevity.

I'd personally rather put that 1200 to use in getting better windows. They are where you REALLY lose heat in the winter.

Rigid foam board <>blown in insulation.

 

[child of wonder]

You'll probably appreciate the improved sound dampening more than the couple dollars saved in heating per month.

Investing it in the windows would also be a smart move.

But, being that you're only planning on being in the house 5 years you might be better off simply holding onto that money unless it's going to save you more than $23 per month somehow (60 months x $23 ~= $1400 ~= $1200 in savings for 5 years).

 

[RadiclDreamer]

Yes, it will dampen sound as well.

 

[desy]

I built 7 yrs ago and wish that I had over insulated, 'in Canada'
Using rigid insulation also removes 'cold ports' which is essentially the 2X6, as its insulating value is nowhere near R20 its R4 , so your overall wall is resulting less than R20

I'd investigate 2X4 walls with 2" rigid but using the Rock wool 'roxul' which is R14 and the foam should be R12 . You'd save on lumber but better material removes the cold ports and give you an overall higher R rating.

Is the blown in the Cellulose insulation or blown glass for the R55?

If you add 1" to the walls for 7" your windows/doors quotes will change too

 

[SphinxnihpS]

http://www.homedepot.com/webap...=10000003+90185+527397

$6.99/32(sqft) = $.21/sqft (contractor pricing is even less at HD, and a good contractor doesn't buy shit at HD because it's mostly all garbage, and it's very expensive).

The contractor is charging you approximately $.44/sqft. (I figured you have roughly 2600sqft of walls based on what you said).

This stuff is EASY to put on!

I think you should offer him $800.

 

[DrPizza]

I can't see the HD price, but $6.99 for a 4x8 sheet sounds kinda cheap to me; I thought it was slightly more expensive for the foil backed rigid insulation. But, don't forget the other "minor" expenses that add up because of that extra inch: all the siding nails have to be 1 inch longer, doors, windows have to have that extra 1 inch, etc. I'm wondering if that $1050 includes the extra costs associated with those, especially the doors and windows as desy pointed out.