Survey revealed roof issues (red light!)

FreeBear

Parliadam said: I would be interested to know where in the UK you are to be getting those quotes and also what size/ style of house you have. The bungalow we are purchasing has quite simple pitched roof (no dormers) running the length of the building. 

East of England, three bed pre-war semi with a hip roof. Scaffolding costs will be lower for a bungalow, but that isn't going to make a huge difference.

stuart45 said: When trussed rafters are replaced the ceiling goes as well, plus electrics etc.

Oh, I'd forgotten about the ceilings. Depending on the age of the property, it could be lath & plaster, so very, very messy work - Could easily add another £1K per room to the price. Although, if the trusses did need replacing, cutting the old ones out an leaving the "joists" supporting the ceiling might be one option.

stuart45

I would think that cutting the trussed rafters to take the ceiling for a while could be an option, as well as sistering the new to the old and just leaving them in.
It needs a chippie to look at the job.

Parliadam

Thanks both for comments. One more question: we’ve been told that the current truss system is not one that enables a loft conversion. This isn’t necessarily something we want, but if the roof needed replacing would it be worth having a type of truss that does offer the possibility of loft conversion in the future, or are these types of truss to heavy for out walls designed only for fink trusses? Bearing in mind the whole house is timber frame construction (1960s/70s). 

stuart45

You would be best to ask an SE about that, although timber frame walls can take a fair amount a weight. Worth thinking about as bungalows usually have a lot of attic space.