Owning your own home

you mentioned something in the difference between needing to seek planning permission and permitted development. Does it sound like this might apply here?

I'm not Brommers but the planning portals on the local authority website will have a list of stuff that's been done / is trying to get done and you can deduce what is permitted development from there as it usually says on the Approval notices under what circumstances the approval was granted.

Speaking of which, I think @Brommers, you mentioned something in the difference between needing to seek planning permission and permitted development. Does it sound like this might apply here?

If it's a listed building you require planning permission, regardless of your PD rights.

Our, hopeful, purchase has half of the ground floor extended for a kitchen, so I let the surveyor know that we might want to extend the rest of the ground floor for a bigger kitchen/diner and maybe a shower room/wc/utility room. Speaking of which, I think @Brommers, you mentioned something in the difference between needing to seek planning permission and permitted development. Does it sound like this might apply here?

It might do. Although from the photograph it looks as though as well as the rear extension there's also been a loft conversion. You can extend your property by a certain percentage under PD rights, beyond that you need PP. You might still have some space left within PD rights - it'd depend on the GIA before the extensions and after. As Prole. says, if it's listed then PD rights don't apply, but I think it was Nelly's prospective purchase that's listed.

It's a real minefield of regulations, and I'm far from an expert on these things. If it's a deal breaker rather than just a 'it'd be nice, but' thing then I'd recommend getting specialist advice on whether you'd need PP and, if so, whether you'd get it.