I am interested in a ICF house but I read some of the down falls I would like to know if it would be possible to have a house that is both ICF with a SIP roof.

 

The company I work with has a Vented SIP roof so that I might shingles instead of a metal roof.

 

Would I be better just have and ICF foundation Radiant heat floor in the basement with “the barrier” as under concrete insulation and a SIP structured house on top.

Have you considered a conventional roof with spray foam insulation?

Sure, that is a common option for ICF homes. However, if the roof is fairly complex, and depending on whether the areas below it are vaulted, I don't always recommend a SIP roof.
That's your call, and it might save you a few bucks. However, if I was building in a Tornado or Hurricane prone area, I might just stay with ICF walls all the way up.

From what i understand spray foam is not cheap and one nice think about pannels it it can be up in hours.

From what I've read and been told, neither are SIPs.

A few months ago I asked the local SIP mfr about using SIP for the floor in the ICF house I was designing for myself. Essentially he said unless I was doing the whole house with SIP it wouldn't pay to do just the floor with SIP. That's because of the structural requirements and the material and labor to construct the panels. I think this same argument could easily be extended to roof panels, particularly if you are in area with a high snow load requirement.

Now that's one opinion based on one conversation so take it for what it's worth.

dmaceld-

It is all dependent on the complexity of the house. A sips floor is going to be more complex because it will require more breaks in the paneling (with engineered floor joist to join the seams) to meet the required live load of the floor. As for the roof we actually have quite a few homes engineered in a heavy snow load areas here in central oregon with sips roofs. 2 of them that I installed were 3/12 pitch and were out of the 10" thick panels.

I have 5 sips roof jobs under my belt. For the original post - In my opinion if the roof of your house is fairly basic and not very cut up, a sips roof can be a very economical way to go, otherwise if you have numerous pitch changes, bastard hips/valleys, don't expect an easy install.  2 things that will make or break a quick sips roof install - 1. Experience 2. Room on site.  

Speaking of snow - Just for giggles heres a sips roof I worked on last week lol:

I'm just about to pour the footings (on Friday) for my ICF house with a SIP roof. The house has 3 separate roofs totaling 3900 sq.ft. with hips, valleys and a few gable ends with deep overhangs. I'm going with SIPs because I wanted vaulted ceilings throughout the house.

The weight of the ICF walls gave some trouble to the engineer. We will run 4x12 PSL roof beams exposed under the panels for the hips, valleys, and ridges. To tie the roof to the walls we are using strap tie holdowns 48 o.c. embedded into the concrete, wrapped around a tapered 3x6 mudsil and nailed off to a double 2x rafter/spline.

I can't say the roof is inexpensive, $12.30 / sq.ft. 3900 sq.ft.