That's useful info - I hadn't thought about noise levels, but it would be in a loft area over a utility room and WC, but the adjacent room is the sitting-room space in the open plan area and will have vaulted ceiling so we will need to think about how we sound-proof that wall potentially.

The only info I've been able to find so far is this video https://www.youtube.com/watch?v=0hChFmvSdbw. I might try and get in touch with person who uploaded it to see if they have any additional insight.

Just wondering how you got on especially with underfloor heating over solid floor combined with low ceiling height - presumably that mrans digging down and adding floor insulation. I have mych in common with my(smaller) stone house but planning on radiators and lowering floor in some areas because of all the ground floor steps.