Years ago we remodeled our bedroom, if it had been recently I probably would have used Ultra fin, would have been tricky as it would have had to be installed from the top before the subfloor. Its not even a crawl space under that part of the house, I honestly think that room used to be a porch that was enclosed. Or maybe I would have done radiant walls then, no duct to that room at all. Fieldstone walls so don’t even want to tackle getting a duct thru em.
Going to remodel the office next, it shares a wall with our bedroom, I’m seriously thinking of taking two rolls of 1/2’ or 5/8” copper and placing fifty foot in a stud bay then doing another for a total of 100’. Place a small register at the bottom and another at the top and see what happens. New windows and siding and we filled any voids when we tore the lathe and plaster down. It doesn’t do bad most of the time, although on colder nights it does get chilly about 4am, a small window unit takes care of AC in the summer.
I figure why not, I already have several other zones set up in the house and have a spot left in the zone controller, just need another zone valve and other miscellaneous supplies.