Trying to warm a ground floor flat - internal wall insulation?

[Scottiekin]

Panicking about keeping the flat warm in winter in Aberdeen - it is a ground floor victorian flat with big not too old front windows. I was offered robotic underfloor foam by a government subsidised company but turned it down having read threads on here re mortgagability etc. Now the same company are suggesting internal wall insulation or some sort of insulation between the outer granite walls and the plasterboard?

Would be so grateful if anyone had any advice whether either is an absolute no go or something they would really recommend. If internal - I know the rooms would get a bit smaller and have also been told the fitted bookcases would have to go. Not sure what the other option they are suggesting (behind the plasterboard is) but injecting something between the wall and the plasterboard concerned about possible damp problems (the room has a fireplace too).

Are there other options I should be thinking about? There isn't enough space under the floor to get in to do mineral wool etc. but I could carpet (the room that seems to lose the most heat (external wall) is big though so would be £) @pigletjohn if you happen to see this would be v grateful for your advice too. This winter is going to be a nightmare if I don't manage to do something before the cold comes.

I don’t have any advice beyond the obvious OP (ie seal any drafts, add carpets/rugs/thick curtains but giving a bump as I’m sure lots of us are thinking about this now

Thank you @BlooberryBiskits! Yes, good idea on draughts - no idea how it even gets so cold so quickly. Literally as soon as the heating is off the temperature plummets inside. Obviously it's pretty cold outside here through the winter but the drop is so quick so keen to do everything I can while it's still warmish. Thank you for bumping.

There’s an article - now very old unfortunately - about installing internal wall insulation here. It sounds like getting someone to fit it might be the biggest issue!

We did the north facing walls of our flat in a similarly northerly location.
We framed it and used kingspan with an air gap. It does take a fair bit off your room but did make a tremendous difference.

Is it something you can get the warm home loan for? They are interest free. We are considering it for solar

It sounds like you have bare floorboards.

These make a room cold by draughts, cold air entering at the bottom and the warm air escaping upwards due to natural convection, perhaps up chimneys or leaky windows, and especially up stairwells in open plan homes or with doors left open.

Carpets or other floor coverings will prevent the cold air coming in through the floor, and draughtproofing of windows and unused fireplaces is relatively cheap and easy. You can use a Joss stick to seek out the gaps because air will be flowing through them on cold days. Under the skirting boards there is a gap that is usually a bad source. If the floor ever has to come up for any reason this is a good time to put mineral wool between the joists. The space under the joists has to be ventilated by the airbricks to prevent damp.

As you can imagine, there is no loss by convection through a floor; practically nothing through radiation, and very little by conduction; it's all in the draughts.

If you can get internal wall insulation, plasterboarded, and decorated on the large external wall, that will cut heat loss a lot, but it is relatively expensive and disruptive.

Be distrustful of contractors unless they have been vetted and recommended by your local authority, energy company or other reputable body. Don't take the contractor's word for it.

I see a lot of scam adverts pretending that there is a subsidy or grant or scrappage scheme reducing the cost of home improvements.

We put carpet down with wool insulating underlay, in our draughty living room and it has made a big difference.