As mentioned before, I hate forced air heating. But last time I looked into getting hydronic space heating (not just floor heating) - it was back in 2000 when I planned the Alameda remodeling - I had problems finding anyone with the right experience. Things have changes since then; hydronic heating seems to fit into the general green building program. I have had two contractors out to look at the task, one of them seemed particularly on top of things.
The task (in the outset) was basically:
Phase 1: Replace my antique furnace and (not so old) water heater with a boiler and boiler heated water heater. Think thermal solar energy.
Build convector boxes in the floor in front of the big windows in the LR, and possibly also in the blue BR. Use panel radiators in other bedrooms and kitchen. Dimension to heater to serve all phases.
Phase 2: [When entryway is ready for roughing-in]
Install floor heating in new entryway (incl. new corridor + powder room + bathroom).
Phase 3: [when kitchen is ready for roughing in]
Install floor heating in new kitchen.
Phase 4: [When the current BA/BR maze gets sorted out, back bath expanded with new floorplan ready for roughing in]
Install floor heating in new BA.
Install towel heater in yellow BA
Phase 5: [when SwimEx is ready to be installed]
Connect to solar panels????
Phase 6: [cannot even think about it]
I found a new UK web site dedicated to radiator. Here it is.
