Shall I replace the current gas warm air central heating?

_Sam_

Thank all I’ll be keeping the existing heating for now, wasn’t entirely sure but it does seem the best and most economical way forward for now esp given the uncertainty with energy out there! 

The floor is so tricky, I’ll look into engineered wood on top of the current floorboards as a possible option... We’ll have a carpet in the bedroom (change the current one) but due to the dogs would like to be able to mop in other areas.

Bendy_House

Lay fibre-board insulation sheets over the existing floor first, and seal them around the perimeter and between each sheet. That will stop unwanted draughts, and add a small - but useful - level of extra insulation.

Between the existing T&G boards, this fibre board, and the new engineered floor, that will be a reasonable level of insulation right there. Floors lose less heat through them than walls and ceilings. But you must stop the draughts...!