Insulating an extension + dividing wall

johnnyjb

Hi im in the middle of buying a house and the Ber was very low , it got an E.
I reckon it is bout 60 years old terraced 3 bed house with single story extension to rear.

I'm wondering the easiest, cheapest way to insulate it to improve rating.

Ill start with loft insulation. It already has double glazed PVC windows.
Ill also lag the cylinder.

I though of insulated slabs on the exterior walls but if i didn't insulate the dividing wall between my neighbors (as its terraced) on each side would that defeat the whole idea.

Also the extension at the rear is a single story torch on felt roof, if i put insulated slab on the ceiling of the extension would that suffice.

( would the existing ceiling slab need to be removed or could the insulated slab be screwed over it)

Sorry for the long post - any ideas are really welcome.

BryanF

if i didn't insulate the dividing wall between my neighbors (as its terraced) on each side would that defeat the whole idea.

no they heat their side you heat yours, job done. although the cold bridges and potential interstitial condensation issues, hanging anything, are why EWI is my preference

Also the extension at the rear is a single story torch on felt roof, if i put insulated slab on the ceiling of the extension would that suffice.

do you have 2.4+ ceiling height? what condition is the structure in? often these old lean-too's need major work and when your moving-in can be the best time to do so

(would the existing ceiling slab need to be removed or could the insulated slab be screwed over it)

what has your surveyor said? you havent told us what other materials in the roof are

words like

suffice, easiest, cheapest

often translate to greater future problems than doing the job right first day.