regularisation certificate is it needed

[miremare]

i bought a ex council house in 2021.
it had a conservatory and extra utility built on when 1st owners bought in 2000.
when i purchased i had a middle survey that was a homebuyers plus the edge of a structural.
the survey was good, no issues were found with the building at all.
all the work was completed as permitted development as they are small add ons.

im selling the house in 2023.
the buyers solicitor ( online firm) are asking for-
proof work was carried out safely and a regularisation certificate obtained.
proof the work carried out is structurally sound.

this is going to be an extra expense for me but it seems as though i cant move forwards with out this .

has anyone else had a similar and has anyone else had to prove these points
many thanks

I was asked for similar but the conservatory was built so long ago in 2003 I think that the current rules didn’t apply back then

I sold without any certificates

thank you did the buyers solicitor ask, push for them or similar?

The response to the buyers solicitor should be along the lines of:

"The work was carried out prior to my ownership, and it is believed to be at least 20 years old. No paperwork or certificates are available."

I think to start with yes . And I had a similar issue with the property I was buying - it had a loft conversion with no paperwork .
the local council confirmed that due to the age of the adaptations they were not interested in issuing any paperwork . The solicitors had to accept this and then the mortgage provider accepted it too .