Yes. Take care that you do not make the accessibility of your shop less suitable for disabled people.

If all of the following conditions are met, no. Otherwise, yes. Conservatories attached to domestic dwellings are exempt from the Building Regulations providing: the internal floor area does not exceed 30m² the roof is transparent or translucent (polycarbonate or similar material which allows light to pass through) the conservatory is constructed at ground floor level

The Council has powers to enable it to control aspects of the demolition of all buildings or structures within the district, except those that are exempt from such control: buildings having an external size of less than 50m3 (this volume is less than the average double garage) extensions on a larger building that consists of