Internal door from utility room to Garage

[signal82]

As title says, i want to fit a door to access our garage from within the house. Its a timber frame build so its just plasterboard I'm going through. Can anyone advise on whether or there are regs as to the actual width the door has to be? I want to fit a 530mm wide door which is more the size for fitting to a storage cupboard. Providing this id FD30 should it be an issue?

Thanks

 

[Nakajo]

If someone manufactures an FD30 to those dimensions, then presumably you can use it. But that does seem a little narrow to be practical to me, and note that you're normally restricted by how much you can trim a fire door down.