In short
Often, yes. The government lists replacing roof coverings on pitched and flat roofs as work that can need building regulations approval. You do not have to apply yourself if the work is done by someone registered with a competent person scheme; otherwise the application goes to a building control body before work starts.
This is a job for our Re-roofing & New Roofs service.
Why a re-roof counts as building work
Taking a roof covering off and putting a new one on affects the structure, the weather-tightness and the insulation of the house, which is what the Building Regulations exist to control. That is why replacing a roof covering is on the government's list of work that can need approval, alongside windows, heating systems and bathrooms.
Repairs versus replacement
Replacing a few tiles, re-bedding a ridge or renewing a flashing is a repair. Stripping and recovering a whole slope or the whole roof is replacement. If you are not sure which side of the line your job falls, ask a building control body before work starts rather than after.
Planning permission is a separate question
Building regulations approval and planning permission are different things and you might need both. Replacing like for like does not usually need planning permission, but a listed building, a conservation area or a change of material can be different. Check with your council.
What we do
When we quote a re-roof we tell you what approval the work needs and how it will be handled, so it is settled before the scaffolding goes up.