[Closed] depress me, glazed extension/garden room/ costs/experiences

Hi

existing conservatory - 2.8m wide, 3.3.m long, bottom 1/3 brick then upvc window walls and polycarb roof, built on to rear/side of house so only 2 walls are actually conservatory if you see what I mean - anyway it tends to be freezing or boiling.

So *assumming** existing base reusable - I'd need a 3.3 m long side wall(pref with some glass at rear end), a 2.8 wide rear wall (want fully opening and all glass) and a proper roof (maybe with skylights)

rough ideas on cost pls

and any recommended supplier near Oxford/Swindon

Thanks