I have a heat pump in such a house, even worse actually since it is a semi-detached. I did not need to do any extra work, and it works fine. My savings are not great, but that is also mostly because I don't have a hot water tank so I still need gas for my hot water. We just replaced 3 radiators, one of which is actually still permanently shut and I am still doubtful about the need for the other twos.
For the walls, it can become quite expensive to insulate it. But at least for the wooden floor, you have a cheap option: lay a new laminate flooring with proper underlay. It will cost typically less than £1000, you'll avoid damaging your wooden flooring, and also improve the thermal confort by removing the air leaks and insulating more.
For the walls, it can become quite expensive to insulate it. But at least for the wooden floor, you have a cheap option: lay a new laminate flooring with proper underlay. It will cost typically less than £1000, you'll avoid damaging your wooden flooring, and also improve the thermal confort by removing the air leaks and insulating more.