Fire door regs for 3-storey flat blocks under 11 metres

[AnthonyB]

Usually the top floor would also be lobbied if it was required, not just the lower floors (not lobbying the top floor is a principle for non residential buildings not flats)

Your layout could well comply without the partitions completely as in this example from the official guidance "A guide to making your small block of flats safe from fire"

 

Without seeing the actual premises and carrying out an FRA I can't be 100% sure but there is a possibility that the doors are not required - also changing hinges does not apply retrospectively either - a common mistake (& money maker for those who remedy it). Also in small blocks retrofitting of strips & seals, whilst desirable, is also not always required.