Some years ago he added a second radiator and last year the double glazed windows and door had the glass replaced by more efficient double glazed units. It has improved each time until Hubby just felt it was chilly at ground level.
The original laminate floor just had a paper underlay over the concrete and as the laminate boards had been glued together it stayed as it was and new was laid on top with a heat reflective foam underlay in between.
So a lot of work moving everything out. Desk legs needed to come off and be cut down before going back on. Hubby on his knees for most of the time over three days. Two new flat pack high shelf units installed. And now a good opportunity to sort stuff before it all goes back.
But when it's all done, unless I'd written it all here you'd probably not even notice the difference just hopefully warmer legs.