I am installing radiant heat capability, can't do it later. Concrete is kinda permanent. I do not plan in using it right away. This is not my first radiant system. I helped my brother install one in his 2500 sqft 16' sidewall shop. He uses a 200,000 btu LP instant how water heater to heat the water. His water heater run at 50% or less of it's capacity when it is running, I suspect that I would only need about 35,000 btu's of hot water heat to very adequately heat my shop. But I have a wood furnace for heat. I do not work out there every day, so radiant heat would not be very efficient for me. All the insulation for the radiant should help keep the shop a lot warmer than outside even without any heat. In the future I may use the radiant, who knows. Todd