Staircase regulations explained
The Building Regulations document (Part K) describes in detail all the requirements for a domestic staircase. Each step comprises a horizontal “going” and a vertical “riser”. The basic requirements of Part K are:-
A maximum angle /”pitch” of 42 degrees (i.e. no steeper)
The total flight must be divided into equal risers, which must be between 150mm and 220mm
The goings must be between 223mm and 320mm
2R+G = 550 to 700 (2 x Rise + Going must be between 550 and 700mm)
Winders and landings are allowed as turns in the staircase
There is no stated minimum width (for some reason!) but most of ours are designed around 750 or 800mm wide, but a minimum of 600mm
2 metres height is required above the staircase treads, which can be slightly lower at the edge where the stairs comes up under a roof slope
Protective handrails must be 900mm high minimum, with 100mm maximum gaps between spindles
Where to put the staircase?
It all begins with an idea.
The design process is explained more fully elsewhere here, but client’s often ask specifically about the staircase location.
In the case of a house the first location we consider is above the existing staircase, as this is often wasted space and it can be a nice feature to have a continuation of the existing access /landing space going up to the new storey. Most loft converters will also be able to match in with the existing newel posts & spindles etc, to make the new work blend in as much as possible. If this location isn’t suitable we will always minimise any intrusion into existing rooms, as there’s no point in ‘losing a room to gain a room’.
A determining factor in staircase location can be the number of bedrooms intended for the loft conversion, as for two bedrooms the new stairs would ideally arrive in the loft somewhere centrally to enable easy access to both rooms without carving off a large chunk for a large landing /corridor. Conversely for one room the stairs are usually best sited at one end of the loft, rather than coming up in the middle and cutting the space in half.
Clients occasionally ask about having a spiral staircase in the hope that it might be more space-saving than a “traditional” one. We’re not usually in favour of spiral staircases as they aren’t actually as space-efficient as people think, and getting furniture up can be quite a problem! However traditional stairs can be designed in any configuration, including a “double-winder” which will efficiently turn through 180 degrees whilst climbing upwards. So we pride ourselves in designing traditional stairs as efficiently as possible, taking up the minimum space whilst fully complying with the regulations and providing comfortable easy access to the new loft space.
Other types of staircases available include a “Space-saver” design (otherwise known as “alternating-tread” or “paddle-tread”) <PHOTO> which are allowed under the Building Regulations but will be very steep - around 60 degrees. They were quite popular in the 1990’s but not so these days. We don’t usually design these into loft conversions as they aren’t everyone’s favourite and can make re-selling the property difficult.