We are building a new home near Edmonton, AB. I don’t know which climate zone to reference based on the US map provided here but I would guess we are a zone 7. Here is some climate info:

5500-6000 HDD annual average
340 mm average annual rainfall
115 cm average annual snowfall

There will be 3 adults and 2 kids (8 and 1 currently) in the house. We are pretty much set on the floorplan at this point but the systems design is a long way from completed. I want a reasonably efficient house at a reasonable cost and this is the plan today (after flip-flopping many times):

OSB/Asphalt shingle roofing
Closed cell spray foam to R20 in ceiling with R50 cellulose blown in on top, creating an unheated attic space
2×6 walls with closed cell spray foam to R27, OSB sheathing, Vinyl siding
Basement walls with wood studs set off from concrete, closed cell spray foam to R27
Basement slab poured on top of 2″ polystyrene
Tri-pane windows, 2 panes with Low E, argon filled, .133 U value, 7.5 R value, .56 SHG, 70% VLT
http://www.allweatherwindows.com/windows.php?sid=131 – window spec here

2 stage variable speed natural gas furnace
16 SEER central A/C unit
HRV
Power drip humidifier
Electric radiant heat in ensuite and main washroom

90% of light fixtures will be recessed LED’s
Power Pipe DWHR for both showers
Flooring will be engineered cork throughout except tile in the washrooms

We have engaged an Energuide adviser to review our plans and come up with alternatives as well. My goal is to attain an Energuide rating of 80. Part of the Energuide rating includes a blower door test. I plan on having the blower door test done at the insulation stage with a smoke machine to look for any leaks in the spray foam and again on completion to obtain the rating label.

I am looking for opinions on my plan as it sits and specifically here are some of the things I have been questioning:

– Hydronic radiant heating: I really want it but have ready many times that it’s main benefits are lessened significantly when the house is well-insulated and air tight. Is my plan above approaching enough insulation and air-tightness to negate the positives of hydronic heating? I’ve considered putting it throughout the house or just the basement and keep coming back to wanting it at least in the basement despite the cost. I’m still not sure why a separate condensing hot water heater hasn’t been designed to work for this purpose as it appears to be much cheaper and as efficient as a boiler.

– Exterior polystyrene insulation instead of sprayfoam: I have had a home with exterior foam and thought it worked well. I went away from it this time because it seems like a bigger babysitting job to ensure it is properly sealed than the sprayfoam.

– Solar energy: I’ve considered solar for DHW and for radiant heating if I did end up going with radiant. With overall costs continuing to climb on the build this has taken a backseat

Appreciate the help and hopefully I haven’t made myself look too foolish with my lack of experience and “low-end” goals.