≥60% of the total heat emitters will be UFH with the rest being reconditioned school rads.
The problem with UHF is the thermal mass of the floor construction. It slows the response time for a change in temperature. Hence there has to be a way to rapidly heat a room. Hence a split between UHF and rads.
When a reduction in room temperature is required it takes time for the thermal mass to cool down. The heat energy of the thermal mass in that situation is wasted with normal UHF systems. Cooling the room may require opening windows. Heat recovery from the thermal mass has been tried ( heat pump system similar to ground coil source ) but the complexity and cost puts it beyond the domestic market.