*this type of climate

Also, do I understand this correctly, in that we CAN use the same system fairly easily?  (See screenshot.)

If it were only so easy…

Consult with a local professional experienced in commercial in-floor radiant design and installation. The building code in Alberta for in-slab radiant might include 4-inch foam insulation between the concrete and the ground.

To prevent freezing, the circulating fluid should be a glycol antifreeze mixture. For efficiency and use of a low temperature liquid, close-spacing of the loops should be included in the design.

“Easily” is a loaded question, as is ‘working’ and ‘working properly’. Don’t look for shortcuts, there’s a lot that goes into a ‘simple’, well designed system with many parts that all have to work together, be installed in the right sequence with the right spacing and being of the right size.

With Hydronics - everything matters - Done right, you’ll love it!

IMPO

SR

Thanks, SR!  My husband is an IBC code consultant, so I'm sure all our building and remodeling will be... exciting.  I grew up in that area, and lots of stuff is done by the seat of the pants (or used to be, 20 years ago!), so it will be an interesting.  Really appreciate your comment.

Your current boiler will likely not be large enough. You’re basically adding a whole full sized house here on the same lot, not a small 12x12 addition next to it. The unconditioned gap is a big barrier to transcended if it can even be done. A fully independent system for the garage will likely be the best.

Knowing building codes and being knowledgeable and experienced in building trades are two very different things. Local jurisdictional building inspectors know codes. You wouldn't want many of them to do any work on your home or other structure. Even though some are former contractors - the ones I know in the "former" category weren't good enough to make a living from that work and they preferred a government job with steady income.

Thanks, Verbo!  Helpful and clear comment.