In rooms which don't have the original decorative ceiling cornices, we are installing suspended ceilings (plasterboard and timber studwork) below the original ceilings. This creates a free route for pipe and cable runs, which both speeds installation and reduces the amount of notching/drilling of load-bearing elements. Today the joiner has started putting up the studwork - and seems remarkably efficient at doing so.
 
Bathroom areas will be ventilated using single-room MVHR units (see this article for a more detailed explanation), mounted within the suspended ceiling voids. So I have provided the joiner with drawings showing where access hatches are to be located, for servicing the MVHR units. Having finalised the positions of these, I've also ordered all the ductwork.
 
The builders have moved off the roof and are now doing the wall-ties. We had a talk about the electrical stuff; I'll be going through everything with the electrician on Wednesday.