One of the issues with internal wall insulation is that joist ends which are set into sockets in the brickwork are at increased risk of decay due to condensation developing on the cut end of the timber...
Meanwhile, the sprinkler first-fix is progressing...
Today was the long-awaited meeting with the window company. Two of them came, spent a good couple of hours on-site discussing the project and taking notes and measurements. They seem genuinely knowledgeable and passionate about their field - sash windows...
The joist nearest the front wall in the first floor bathroom was rotten, due to historic water leakage from the bath (note, this is a particular danger in highly-insulated houses!)...