Garage conversion

If window/velux is going to be fitted then you would need planning permission.

Yes if you are adding a door or extra windows or velux then you will need planning permission

In general, if the conversion involves any structural changes to the garage, such as installing windows or doors, altering the roof or changing the external appearance of the garage, planning permission may be required. Additionally, if the office will be used for business purposes and customers or clients will be visiting the property, planning permission may also be required. However, if the conversion is purely internal and does not involve any external changes to the garage, planning permission may not be required. It's always a good idea to check with your local planning department to determine if planning permission is needed for your specific project. Keep in mind that even if planning permission is not required, you may still need to obtain building regulations approval for the work to ensure that it meets safety and energy efficiency standards.

If you intend to use it as an office for more than two days a week then you need planning permission.