Hello.. i need some advice about the number of doors you are allowed in a fire exit route. I have a ground floor shop 77msq .. there is an exit at the front and one at the rear through the kitchen. Am I able to partition off the kitchen .. meaning if you wanted to use the rear fire escape you would first have to go through the door to the kitchen? How many doors is it ok to have to go through?

There is no limit on the number of doors you have to pass through to escape from fire providing they are easily openable in the event of a fire.

As Tom said, there is no limit on the number of doors in a fire exit route. However, kitchens/kitchenettes are considered fire hazard rooms and you shouldn't  consider that an alternative means of escape from any other part of the building except from that particular kitchen (e.g.: not allowed to escape from a normal risk area <office> through a high risk area <kitchen>). You will need to considerate another escape route from the building.