On Mar 5, 3:20*am, Alim Nassor wrote:
Hi guys. *My wife and I are in the late planning stages of building
our new home. *I want it to be as energy efficient as possible. *We
are having a slight disagreement.

I want foam insualtion in walls and attic. *She is ok with that. *What
we disagree about is how to do the attic.

Her ex-husband is a HVAC contractor. *He says we should use the " foam
the underside of the roof, seal the attic and semi condition it"
method. *Our builder agrees.

My problem with that is, why would I want to semi condition an area
the same size as my house if I am never going to use it for anything?
I want to foam the attic floor, and make sure the attic is well
venitaled. *Why is allowing my warm and cold air (that I am paying *to
heat and cool) to migrate up into my attic a good idea? *Isn't it more
efficient to keep that expensive air in the house by well insulating
the attic floor?

Can anyone give me advice on why my thoughts are wrong?

Your builder and wife are both correct but I don't think you
understand that they meant doing both the ceiling and the roof. Your
logic is also correct given your apparent misunderstanding of what
they meant. The roof insulation must be installed properly with an
airspace between the roof and insulation providing an air duct from
the eve to the ridge. If you don't do this the life of your shingles
will be greatly reduced. I suggest you don't let this attic space go
to waste.

Jimmie