We have recently purchased the 20x30 1.5-story house plans and we are moving forward with the planning stage. Wondering if we can get some advice and information here.
First, a little info: We want to extend the house 10 feet, so the footprint will be 20x40. The additional 10 feet will have an extra bedroom and a mudroom...otherwise the floor plan is the same. The loft will be above the bedrooms/bathroom/mudroom, but the great room/kitchen will have cathedral ceilings. We have a builder and he has agreed to let us work with him and do a bit of the work ourselves to keep the price of the house lower. The house will be on a slab, with radiant floor heating. I will attach floor plans when we get them drawn.
My first question is this: We'd like to frame the house 24" OC instead of 16" to improve R-values in the walls. Any reason not to do that? We would like the loft flooring to be T&G pine, if that's helpful.
Second question: Has anyone installed a air-to-air heat exchanger in their house? I'm wondering what that looks like if you have radiant floor heating and no air ducts.
Thanks in advance for any suggestions!
If there is a ridgebeam or real trusses then structurally it is ok. If there are just tall studs, notched for a ledger and inadequate ties then this is making a high stress situation worse.
24" framing can show more wave in the wall sheathing materials, it is a tradeoff for fewer thermal breaks.
You will want to use locally engineered trusses for the roof. In the cathedral areas the walls should not be taller than 10' or ties will likely have to be engineered. If you have all trusses then the walls can be platform framed and studs can be 24" o/c. You will likely want to go to thicker drywall (5/8").
Check with the HRV supplier/installer to see if they can place a small unit somewhere in the main floor ceiling.
Ditto on the wall waviness issue... 5/8" will help, but it may still be noticeable.
My experience has been that 5/8" type X works fine; laid them horizontally. 1x6 T&G pine/aspen also worked out fine.
I'm not sure how much better the total insulation package comes out with 24", unless you also go with the advanced framing techniques that also eliminates some of the 2x6 framing around doors and windows, as well as those new fangled ways of building an inside corner to accept the drywall. E
Every little bit helps I suppose. But I wonder if a few extra bags of cellulose blown into the attic would make up for all the wall framing tricks.
Sheet foam over the studs works too. ???
Thanks so much for all the replies!