Hi guys thanks for getting back to me,,, at the moment all I can tell you is the lower half of the house is brick, the upper half is ceder shiplap cladding, which isn't bad condition but has been recommended by a previous surveyor to be changed, I've not seen between the walls yet but as soon as I know more I will come back here, I've heard that I'm not supposed to fill the cavity! Well with rockwool but not sure if I can use anything else?? I was just going to replace the plasterboard with something better, I will check out the frame therm, regards Michael