I am still looking for a heat delivery system for an old house retrofit. I have a new condensing boiler, and love the idea of radiant floors but don’t want to rip up the old floor. Staple up under 1 3/4″ of old wood doesn’t seem like a great idea. Most of the plaster walls have to come down anyway (water damage) and I am wondering why not use radiant in the lower portion of the walls. Exterior walls are 4″ (true) and will be cellulose insulated. I feel like there would be less heat loss if I use interior walls but would that be uncomfortable feeling? I am saving the old windows– fixing them up and adding storms. Any thoughts or experience? I am also considering putting old cast iron radiators back in but hate to use up the floor space.

Thanks