Approved Documents B, K and M along with BS5395 form the basis of this confusion.

We have today received clarification from Kevin Johnson at Redcar and Cleveland that Approved document M takes precedence and that the criteria to adopt should be as follows: -

1200mm min wide tread width (measured from face of plaster to the edge of the flight – (not the wall stringer skirting )

Suggest the minimum gap between flights where they return on themselves be no less that 200mm ( not covered by Building Regulations just seen as good practice particularly when balusters are palm fixed )

1000mm min between handrails – whether palm or to top of tread fixed

Rise between 150 and 170mm

Tread length min 250mm

Landing length min 1200mm or same as the width of the flight where greater

Maximum number of risers in a flight before a landing becomes necessary – 12no.

Wheel chair refuges, (1400x900mm) are required at upper floors and even at a ground floor level where additional risers are required to reach a lowered external ground level where not served by a ramp.

Handrails 900mm above pitch

1100mm above intermediate and top landings

Hand rails to terminate 300mm from the top and bottom rise

And finally and again good building practice, often neglected in scheme design is that the last rise of a lower flight should be a full tread length before the first riser of the returning flight – just makes for a better hand rail design.

Whilst the information was meant to be definitive, some Building Control officers still may require a main stair ( accommodation ) to be 280mm as identified in AD K. This document is apparently in the process of being re-written and hopefully the matter will be further clarified when it is re- issued April 2007. Clearly if in doubt check with the relevant local Building Control Department.