Chalet Bungalow. Need to improve insulation - Help

[GreenShadow]

We have a chalet bungalow with two bedrooms up in the roof. There is absolute minimal insulation in between ceiling and roof tiles.
We desperately need to improve this insulation - but don't know how. There's no room to lower the ceiling as roof height is already minimal. Is there any other option other than raising the roof - at some extortionate expense?

Along with this, we were hoping to put in some large dormers but have just had planning permission turned down (for aesthetic reasons).

We just don't know where to go from here....

Anyone done similar?

We are currently insulating an end terrace wall with tanking slurry and insulated plasterboard. (Along with repairs to external wall). It's only half installed but I can feel the change in wall temperature already.

Rockwool thermal lining paper? My friend did her jutting out room with it and said it was like adding two breezeblocks.

Can you do that in the ceiling though?

You should have a local energy advice centre who may be able to help

Interesting. Thank you. will have a look at this.

Sorry - I haven't been 'quoting' comments, so my replies aren't lining up properly...