Width of a single step outside a final exit door

[Tadees]

When entering and exiting a block of flats, there is a single step immediately outside the exit door, which whilst inspecting I completely missed.  I can therefore imagine somone falling over at the time of leaving the building.  My questions are therefore thereefoldfold.

1. What's the minimum width a single step should be outside an exit door from a dwelling?
2. What should be the maximum height of the step?
2. What are the potential solutions where apart from making the width of the step bigger so that in future others do not completely miss the step, fall over and break their neck?

[kurnal]

See ADB B1 para 5.21 and 5.32 in respect of single steps and ADK1 in respect of rise and going and the design of ramps. You will find the answers therein, unless you also wish to mix in ADM and BS8300 for disabled access and egress.

[Tadees]

Thanks