Will electric in-floor heat be adequate in a converted barn?
I agree with Ed Beal, get the plans of the layout. Also, confirm if the building, slab or crawlspace was indeed insulated or everything was inspected &amp; what Passes or Fails were issued. I'd also put a Contingency in the Agreement Of Sale that it must be found to be completely sound. You'd have an Electrician test what he can, even if it's just continuity readings.

If it doesn't or can't be checked out, then see what you might be allowed to use to assist, supplement or replace it with. Like: Electric Baseboards, Wood Stoves, Passive Solar, More or Better Insulation or Geo-Thermal Heat Pump.