Addition of electric radiators

FreeBear

Judester said:

Keep_pedalling said:

Get curtains with a shorter drop, and insulate the wall. 

What is the best way to insulate the wall given there is no cavity to fill?

Probably the most effective method would be to fix 100mm slabs of either woodfibre or cork boards to the wall and skim with a lime plaster. You'd need to fix some battens to the wall to take the weight of the radiator (unless you move it to another wall). Window boards would need to be made wider, and skirting would need to be trimmed & refitted. Someone like Mike Wye would be able to supply all the materials you'd need.

Some would say use Celotex or polystyrene boards (either internally or externally), but this will trap moisture in the wall, leading to big/expensive problems in the future.

I've insulated some of the walls here internally, and to be quite honest, not really noticed much improvement on heating efficiency. However, it has cut condensation forming on the walls, so is doing something.

Judester said:

Albermarle said:

sk2402005 said:

Adding additional heating capacity by way of larger or more radiators is the best way to go in tghe longer run, electrical heating is very exensive to run.

Your open fire is certainly not helping you, its will actually be cooling the rest of the house by drawing in so much fresh air - open fires at best are 20% efficient, a stove can be 80% - so unless you like the look of your open fire, really you are probably wasting your time. AFAIK , an open gas fire ( with artificial coals) are more efficient than 20%, especially the newer ones. Also they can give out some good supplementary heat, often to a side of the room that has no radiators. Not super efficient for sure, but OK as a cosy add on heat source in a cold gloomy February,

If you can get free wood, then you migth be best placed looking into a wood burning stove, its hugely more efficient but some would say more environmentally unfriendly, due to the particulate emissions.

If your buying your wood then its probably actually cheaper to run the central heating, it almost certainly will be vs your open fire, that is unless your central heating boiler is really old.

A couple of comments in bold. 

The open fire is staying, I love it! It isn't a gas fire, just smokeless coal and logs. We have plenty of free logs to burn (particularly after the recent storm, have enough for several years). 

You would be quite shocked at the amount of heat lost up an open chimney - One heat loss spreadsheet I looked at estimated 2kW. Fitting a stove was one of the best things I've done here.

grumpy_codger

FreeBear said:

  One heat loss spreadsheet I looked at estimated 2kWh.

kW - I think. I'm a hopeless pedant.

Keep_pedalling

Judester said:

Keep_pedalling said:

Get curtains with a shorter drop, and insulate the wall. 

What is the best way to insulate the wall given there is no cavity to fill? 
I tuck the curtains up, there is also a sofa beside that radiator which can't go elsewhere so not an ideal location. I'm not a fan of short curtains unfortunately!

You have a couple of options, external or internal. Internal is more disruptive but with a large room it could be a good option as it avoids changing the external appearance of the house.

https://energysavingtrust.org.uk/advice/solid-wall-insulation/