After looking at the options for installing radiant floor pex tubing in my new home I'm trying to choose the best way.
Installing in between floor joints seems more labor intensive, less efficient, and potentially less effective because its so far below the finished flooring material. I factor in the cost of heat transfer plates and the insulation below it and it doesn't seem alot cheaper either.

I've been looking into the the "sandwich" method (tubing on subfloor and then installing sleepers in between, still using heat transfer plates and possibly an aluminum foil material. It seems to be more time consuming but easier to install, I think the ability adjust the spacing around more important areas and areas that don't need as much heat allows it to be more effective and I like how can cater to the flooring material a little easier. Cost wise it seems pretty close but its hard for me to tell. It seems like you could use the plates a little more sparingly but beyond the cost the additional wood for sleepers I Haven't done a lot of research.
My concern with the sandwich method is the height I would be raising the finish floor overall having any affect on my walls or other framing that I'm neglecting to thinking of and leading to other problems. Windows would still be above the safety glass requirement height, I had exterior door openings made an 1.5" higher and interior walls aren't built yet. This all led to me to think of an idea that I expect to be flawed but I'm not positive.
Would it be possible to router a 3/4" channel in the original subfloor, lay in heat transfer plates and then route pex in the routed channel avoiding the need for sleepers and keeping the any height increases minimal. Keep in mind I'm doing the labor myself even though it would be a time consuming nightmare and not a good idea for a contractor to use repeatedly-I would only have to struggle through it once.
Last but not least-brand new home with geothermal heat source with target temps of 115-120 for radiant tubing, flooring materials range from carpet to engineered hardwood and small amounts of tile.