We are building a very different home in Prince Edward Island (Northeastern Canada). It's a Deltec home (www.deltechomes.com) from North Carolina & very energy efficient from a design aspect (i.e. less drafting due to its round nature, etc.). We are doing a 2 level, with each level being 2,500 sq. ft. The basement is about 3,000 sq. ft., is perfectly round, & made using ICFs.

The 1st level will be divided into 4 x 625 sq. ft. rental units and the upper level (2,500 sq. ft.) will be where we live.

We will be adding solar panels to the roof at a later date.

The interesting thing about the house (& not to say that this would have any impact on the heating/cooling method we use) is the fact that the house rotates 360 degrees via a steel platform that is sunk into the basement and extends out past the top of the basement walls.

I was considering minisplits for the units downstairs, but was unsure what we should use for the upstairs, which has 4 bedrooms on one side of the house and one big room containing the kitchen, living room, etc. on the other side of the circle.

Because Prince Edward Island can get -30°C weather (-22°F), however, I'm not sure whether the minisplits can adequately handle heating the house, but I do understand that they are improving all the time.

If we didn't have to have AC for a few days during the summer every year, I would go solely with radiant heat as I'm told it provides very comfortable heat at low operating temperatures.

I'm trying to avoid having 2 completely separate heating systems, but I'm not sure if it can be avoided as I'm worried that the splitters won't cut it in the extreme cold. My builder has told me that the house is so well insulated & built (6" walls, insulated headers, BIBs, etc.) that the splitters should do the trick for the entire house, but that we could wire it for electric heat just in case & simply put baseboard, dimplex, or convection heaters to supplement if necessary.

Can anybody give me some suggestions on what might be the best solution? If we do go with radiant floor heating, are the electric "mats" better/worse than the hot water pipes?

I was reading on this forum that there is a heat pump that can tie into an in-floor radiant heating system - maybe this is the route to go?

Any thoughts or help would be appreciated.

Thanks!