Insulation external walls

[Bod ...]

A job for next year.

My daughters room has two external walls. I'm looking at replacing the window with triple glazing and insulating the walls.

I'm looking at using this stuff

25mm Ecotherm Eco-Liner Insulated Plasterboard 1200mm x 2400mm + 12.5mm P/B | Insulation Wholesale

25mm + 12.5mm EcoTherm EcoLiner Insulated Plasterboard is suitable for internal wall insulation for solid, cavity or timber frame walls within new and existing properties. EcoTherm Eco-Liner comprises a fibre-free rigid polyisocyanurate (PIR) insulation core bonded to 12.5mm tapered edge gypsum...

insulationwholesale.co.uk

Is that the purpose of this stuff?

I'm thinking of dot and dabbing then getting a plasterer to finish it off for painting.

Will it work in keeping the house warm and keeping the heating bills down.

 

[Mr Chibs]

I'd say not thick enough.

50mm PIR would be a minimum to make it worthwhile.

 

[Diver Fred]

I'd say not thick enough.

50mm PIR would be a minimum to make it worthwhile.

Agreed. Don't forget to insulate the window reveals. It would be better to go for 100mm insulation on the outside all over the house. I did that and it reduced my heating bills by around 50%

 

[Bod ...]

I'd say not thick enough.

50mm PIR would be a minimum to make it worthwhile.

50mm would be the max I'd want to go with 25mm on the reveals.

 

[Bod ...]

Agreed. Don't forget to insulate the window reveals. It would be better to go for 100mm insulation on the outside all over the house. I did that and it reduced my heating bills by around 50%

How did you go about that? I could do my Gable end that way.