I'm in the initial planning stages of replacing my 1970s built cottage in Central Ontario. The new structure will be a two-story with full basement, between 1700-2000 sqft and will eventually be my primary residence for most of the year when I retire. In addition to the superior insulating properties, I've read that ICF structures can offer better protection against rodent infiltration? We have an abundance of field mice and have "controlled" the population through careful application of rodenticides but have never managed to eliminate them from infiltrating our cottage which is primarily wood/block construction. They are causing havoc with the insulation and so I'm thinking that since I'd like to replace the existing cottage with new four season structure, ICF would be my best choice? What about the roof? It would seem to me that a conventional wood roof/truss installation would allow for the mice to infiltrate the structure so would an ICF/concrete roof potentially eliminate the problem? Appreciate your thoughts.

Rodents no experience their, maybe someone else can hit you up on that.

As for the roof, I find a SSIP (Steel Insulated Panels) roof system a perfect match for ICF construction. It would offer a great high performance alternative to tradition wood truss framing. Check out some of the forum post under Structural Insulated Panels (SIPs)

Once you move in I highly recommend acquiring a rodent prevention unit, otherwise known as a cat.

ICF walls would be a good choice. Again and again it has been shown that mice have a hard time nibbling through 6" of concrete. You still have to make sure that the inevitable penetrations are rodent proof. And, it is not unusual for the little fellers to get into the outer layer of insulation. Flashing and screens at ground level are important and I've noticed that contractors don't bother with details like that.

I wouldn't put in a special roof just to address the rodent challenge. It's easy enough to simply make sure that standard construction is properly executed, once you are up at the roof level.

Most important is to not expose any raw foam around ground level. So ensure perimeter flashing partially buried and contiguous up to the siding or whatever.

I've seen mice tunnel into foam at ground level and then tunnel all the way up to the attic, which they lived happily for years until discovered.

ICF/concrete works great in stopping rodents. Chewing through 6" of reinforced concrete is something that is not easily done. Preventing the rodents from damaging the EPS on the exterior can be done by using EIFS. This creates a very tough and rigid barrier. StuccoMax is a great product that works well to protect the EPS.