Radiant floor heat is my favorite form of heating.
Here we'll add 1 1/2 to the wall height and pour gypcrete on the entire floor then zone each room.
You use a type of glycol to carry the heat from the boiler to the zones.
Make sure you insulate the ground with extruded polystyrene.
I recommend at least 8-10 inches under the concrete. It will save you money down the road. The extra couple hundred in insulation will pay for itself.
And look into wood fired boilers to supplement the main boiler.
We built a house where the entire home was radiant floor heat that had a gas fired primary and a wood secondary.
The wood secondary was a shed with the boiler inside. The sheds roof flipped open. To expose a boiler large enough to drop tree stumps into. They would burn for a week at a time.
The owner of the home had a tree pruning,tree removal and stump removal business so in the winter basically the customer paid for him to remove their stumps and dispose of them to which he disposed of in his boiler which heated his home and 5000 square foot shop.
We also build 4 storey walk ups here(apartments) that heat with radiant floor heat using a wet system,not an electric type.
My first house I built for myself had a gas boiler for the house. In my detached garage I had a wood burning boiler.
I could open a valve which pumped heated fluid to my shop(gas fired) but I could also turn of the gas fired boiler and run straight from my wood burner.
My gas bills in that house cost me more in the summer than in the winter because in the summer I didn't start the wood fired boiler but in winter the gas burner never ran at all.
My natural gas bills annually never exceeded 600 dollars.
The wood was free because I'd bring it home from work.
I charged the builder for site clean up and disposal which was 1000 dollars per house to be completed after shingles were installed.
So the shingles went to the dump which cost me 50 bucks. The lumber came to my house.
My men know that nothing larger than 24 inches goes into the garbage until the house is 100% complete and it passed inspection.
So my wood burner always had easily handled and stacked pieces ready for burning. The customer paid me to remove and dispose,I paid my men to do the clean up,and stack everything and at the end of the day in our cold sask winters my heat actually paid me to use it because once it was all said and done it was stacked ready to burn and I turned a profit.
Yeah wet radiant floor heat costs about 20% more for in labour however because there were no bulkhead drops in my basement as well as less framing problems going around various ducts.
And in my cantilevers I had hear right to the end of wall therefore no cold spots anywhere.
I also used spray foam wall insulation adding further weather tightness.
The only thing I will say about building that right is venting for fresh air movement. I had fans in all the bathrooms and kitchen but if I had to do it again I'd have bigger fans that moved more air.
And the garage got so hot and melted the snow,evaporating very fast it created a sauna that was just unreal so I suggest mechanical fans such as used in bathrooms and I'd use a moisture type sensor to actuate the fans to exhaust it in a hurry,otherwise the paint will come off the walls in a big sheet.
