Cheers, Jeremy. An ASHP (playing with Stroma) seems to give an increase in the EPC number of a few points - tested by simply replacing the Combi Boiler in the Model with an ASHP. Which is, however, a slightly crude test.      @A_L   a -  thanks for the comment. Keen to hear more of your experience.   c - I am not sure that I agree entirely with your "c" reply.   My current floor renovations give me a floor U-value of just under 0.25, which I think i