Bit late to this thread but...
Quote:If all answers are 'Yes' then no problem, if some are answered 'No', then they state that Building Regs Approval is needed.
That's not quite correct.
You always have to comply with the Building Regulations BUT it's not always necessary to make a Building Control Application.
I can't tell from the info provided if an application should have been made when it was built.
Is it more than 15sqm? More than 30 sqm?
Heated?
Exterior grade door between it and the house?
In your case...
Quote:Q. Does glazing satisfy the requirements of Part N Schedule 1 ( toughened safety glass )?
A. No, just bog standard single glazed.
..it appears the conservatory does not comply with the Building Regulations as they require safety glass in certain locations. So if you did make an application it might well fail.
However I wouldn't bother to do anything. You could try telling the buyer that you took the lack of building control approval into account when you set the asking price but that might not wash unless you mentioned it when they were looking around. The buyer is also free to decide that they assumed it had Building Control Approval when they made their offer. So it's up to you both to negotiate the selling price. It's like buying a 2nd hand car the price you agree usually takes into account the MOT and any service history.
It's possible the buyer or their solicitor will also ask you to take out a single premium insurance policy to cover them should Building Control turn up and demand Building Control Approval be obtained. Google suggests these policies cost between £30 and £1000 but I've never had to buy one so I don't know if they can be really that cheap.
PS It's probably too late for the planners to demand you apply for planning permission. They usually have 4 years to do that (or 10 years if there has been a "change of use" or breech of a planning condition in the permission for the original house).