Spiral Staircase Regulations

Building Regulations

For spiral staircases the relevant regulation to follow is British Standard 5395 part 2. This is split down into 5 categories as shown in the chart below.

Here at Elite we pride ourselves in guaranteeing we can supply our staircases, anything 1370mm diameter or over, to conform to these building regulations.

Please feel free to contact us with any queries or concerns you may have about meeting building regulations. We are here to offer expert advice, after all we have been manufacturing spiral staircases since 1987.

Part K of building regulations covers protection from falling, collision and impact. This is especially relevant in our industry for handrail heights and balustrade spacing. Again we’ll ensure our products meet part K and that there no gaps greater than 100mm.

Category A – Small Private Stair

Secondary domestic stair intended to be used by a limited number of people. This can be used if only serving one room.

Minimum Clear Tread Width 600mm – minimum diameter 1370mm +
Riser Height 170-220mm
Minimum Inner Going 120mm
Minimum Centre Going 145mm
Maximum Outer Going 350mm

Category C – Small Semi Public Stair

Small commercial stair providing access for up to 50 people. Most commonly used in small factory, shop and office.
Can be used as a fire escape.

Minimum Clear Tread Width 800mm – minimum diameter 2100mm
Riser Height 170-220mm
Minimum Inner Going 150mm
Minimum Centre Going 230mm
Maximum Outer Going 350mm

Category E – Public Stair

Large commercial stair designed to be used by many people at one time e.g. place of public assembly.

Minimum Clear Tread Width 1000mm – typical minimum diameter 2500mm
Riser Height 150-190mm
Minimum Inner Going 150mm
Minimum Centre Going 1250mm
Maximum Outer Going 450mm

Category B – Main Private Stair

Providing the main access to the upper floor of a private dwelling. Minimum required if serving more than one room.

Minimum Clear Tread Width 800mm – minimum diameter 1830mm +
Riser Height 170-220mm
Minimum Inner Going 120mm
Minimum Centre Going 190mm
Maximum Outer Going 350mm

Category D – Semi Public Stair

Intended to be used by large numbers of people, some of whom may be unfamiliar with the stair. Most commonly used in factory, shop and office. Can be used as a fire escape.

Minimum Clear Tread Width 1000mm – typical minimum diameter 2500mm
Riser Height 150-190mm
Minimum Inner Going 150mm
Minimum Centre Going 250mm
Maximum Outer Going 450mm