I saw your forum about BR and retrofitting insulation. This has haunted me for the past year. I have a listed building with planning for dormers. This triggered building control requiring thermal upgrades. To comply would mean covering all the historic beams - the character I bought the building for!. Furthermore planning conservation weren’t receptive to non breathable systems such as PIR or Rockwall which provide better u values than vapour permeable ones and are a lot cheaper!. I looked at regs and thought as a listed building I may be exempt from complying. I emailed the conservation officer for his views and asked that he draft a response that intervention may be detrimental to the historic building. I wanted to insulate for my comfort (uninsulated walls wafer thin weatherboard on timber stud with lathe and plaster, others bare double skin brick, no membrane just naked tiles on rafters to roof) and shared some vp insulated membrane systems and sheep’s wool ideas that he accepted. I did some research - sought advise from specialists and proposed to building control different thermal upgrade systems using hygroscopic breathable insulation including tlx gold, activis silver, wood wool, thermafleece, wood fibre and lime plaster each bespoke to all manor of different construction types added to the building over the past 400 years! I sent the best u values achievable to Building control and carried out the works. £60k later (specialist plasters and insulation don’t come cheap) and the building is functioning well but the conservation officer left and building control won’t sign off based on email communication and notional approved systems and want an exception letter which the new team won’t do. I don’t get my sign off.
