Victorian house top floor insulation

[noworklifebalance]

We live in a three storey Victorian house - the top floor is not a loft conversion per se.

It’s cold in the winter and hot in the summer - part of the reason for it being cold is that the central heating is not great up there.

So, my questions are whether insulating the walls would make a big difference in the winter and whether it would actually make the rooms hotter in the summer?
Cavity insulation is not possible so it will be very disruptive and expensive.

TIA

Bump

Yes, insulation is the key to making the top floor warmer. Insulating the walls is good, but the roof is likely to be the more important as it's a larger area and "heat rises".

Is it right up under the roof, with no roof space above it? The best approach is probably to remove the ceilings and insulate between and under the rafters as would be done on a new build or for a loft conversion. It's not an especially expensive job, but much more expensive than rolling out loft insulation. It will also be messy and disruptive as you'll have to move out of those rooms.

I would have thought a lot of heat would be going out through windows and roof, more than walls anyway.

Assuming you have hot water radiator central heating — is your boiler and heating system up to pumping up to the second floor? Friend of mine bought a townhouse and I don’t know the technical ins and outs but I do know they had to replace the boiler, because it wasn’t ‘strong’ enough to pump up to the second floor properly. Solved the winter issues, and cheaper than a new roof.

Similar aged house here. We dry-lined the internal walls and insulated the roof and it made a huge difference. The attic rooms with south facing windows can get very hot in summer but it’s been worth it for the benefits for the rest of the year.