Providing the front door is less than 4.5 metres above ground level the advice given in the above door section is applicable. However, in those situations where this is not the case, i.e., most typically flats two floors or more above ground level, the level of security is dictated, to a degree, by statutory fire regulations. Their basis is that the Fire Brigade should not be hindered unreasonably in its job of rescuing trapped occupants.
These regulations prohibit the fitting of a locking device on the front/final exit door which, if operated, requires a key release to open it from the inside. This would exclude the use of standard mortice deadlocks if they can be operated from the inside. They specify that exit from the flat is achieved by the operation of a single action release, opening being accomplished by means of a handle or thumb turn.