In terms of embodied energythe total amount of energy it takes to make a material (or a building). See more on embodied energy the use of timber in staircases is far better than metal. However the timber should be sustainably sourced and be FSCForest Stewardship Council (who accredit timber) see their database or PEFCProgramme for the Endorsement of Forest Certification. See their web site woodmarked. One of the traditionally favourite timbers for the manufacture of staircases has been parana pine (Araucaria angustifolia) from Brazil but this is now critically endangered. see more on Parana pine
It is on the IUCN Red List of Threatened Species as a critically endangered species.
‘Since 2001 there has been an official Brazilian ban on log exports of this species. The Brazilian Government is also promoting several initiatives to protect Araucaria genetic resources’
Although many staircases are now supplied as whole systems which are modified for the particular purpose, there are still many occasions when it may be better to revert to traditional joinery, metalwork or masonry. This is particularly true where repairs, changes or extensions are being made to a house or traditional features require matching. The exception to this is spiral stairs where it usually makes sense to utilise a prefabricated system.
The stairs always seem to take up more space than you first imagined (often around 8% or more of the total floor area when you include the associated landings) so it is good to work out a rough size and configuration at an early stage of designing a house. This is particularly true for the relationship of circulation space[for the purposes of part B of the Approved Documents] A space (including a protected stairway) mainly used as a means of access between a room and an exit from the building or compartment between different floors. There are several factors which influence the design of stairs:
• the vertical relationship of the landings the stairs serve see more
One straight flight
At its simplest this involves a straight flight with a landing area at the top and bottom. This is usually the cheapest type to build and is most economical in terms of floorspace, taking up about 10 m² in total (i.e. both floors). Because the lower and upper landing are so far apart horizontally it may be difficult to fit in with the room layout. This is the layout generally used when the lower landing is in the hall or living room near the front door.
The spaces around, under and above stairs can range from grubby little cupboards to opportunities to display all kinds of beautiful artefacts such as plants, pictures works of art, creative lighting etc. This is more true with open tread and spiral stairs where the spaces are more visible.
Not that there is anything wrong with cupboards under stairs but given the non-rectangular, somewhat sculptural shape of stairs it provides a chance to be creative. With long straight flights it may leave space beneath the stairs for a doorway through to another room or a small space for a desk, stereo etc.
Half landing return.
Because of space configurations there is often a half landing and then a turn of 180°.
This allows the top landing to be vertically above the bottom one which may be useful with some types of room layout, especially for external stairs. It’s more expensive to build and takes up about 14 m² of floor plan. It may also be more difficult to arrive at a good design for the spaces below the stairs so it can look a bit poky.
Alternately a turn of 90° may work and this configuration can be particularly useful if you are wanting to link lower and upper floors where the circulation spaces don’t match easily, for instance if you are linking together two existing adjacent properties. Adjusting where the half landing occurs on the stairs can also be used to make adjustments between irregular floor levels. Takes up 12 m² of floor plan.
• the aesthetic value of the stairs see more
They can be beautiful in a purely sculptural way, especially regarding the materials they are made of.
They give a different vertical quality to a space, especially when there is some visual connection between the two storeys they serve:
The book ‘A Pattern Language‘ goes into this in one of its patterns called ‘Staircase as a stage’
“A staircase is not just a way of getting from one floor to another. The stair is itself a space, a volume, a part of the building; and unless this space is made to live, it will be a dead spot, and work to disconnect the building and to tear its processes apart”
The point is also made that people often like to sit on stairs and may use stairs to make an ‘entry’ into a room. So the advice goes:
“Place the main stair in a key position, central and visible. Treat the whole staircase as a room (or if it is outside, as a courtyard). Arrange it so that the stair and the room are one, with the stair coming down around one or two walls of the room. Flair out the bottom of the stair with open windows or balustrades and with wide steps so that people coming down the stair become part of the action in the room while they are on the stair, and so that people below will naturally use the stair for seats.”
Stairs on an outside wall can be lit by a tall window: the Victorians often commissioned stained glass work for these. Half landings can incorporate areas to place objects of beauty or window seats. Pattern Language suggests a window affording a Zen view. Landings can be very interesting areas especially if they are part of a gallery[for the purposes of part B of the Approved Documents] - A raised area or platform around the sides or at the back of a room which provides extra space. which overlooks rooms below or a courtyard.
• the cost which can vary enormously see more
• the type of construction and materials see more
Stair treads obviously need to be hard wearing and it is almost as if stairs have been divided into two types historically: ones which were meant to be carpeted and ones which were meant to be left exposed.
The carpeted ones (usually with timber risers) were normally with softwood treads which wear down if not covered.
The exposed ones tend to be mainly hardwood but also stone, concrete, terrazzo, steel (usually with a covering such as cork, rubber, timber etc.).
If you are using timber for the stairs then this is an opportunity to show off some of our beautiful native timbers. Because staircases use a relatively small volume of timber it is possible to splash out and use the best. Most people know of ash and oak but there are several more exotic species in terms of colour and grain. Native cherry has slightly pink streaks with yellow markings. Native yew is very exotic in terms of its rich red/brown grain mixed with cream. The fruit woods are light in colour and elm has a rich and charming grain. Alder can have strong streaks of red if treated with oil.
• the possibility of stair lifts / lifts see more
The section on Disabled Access indicates how lifts might relate to stairs and landings. In the case of stair lifts there is a case for designing stairs so they may take a stair lift at a later date. This involves the width of the stair, structural support for the lift, adequate space on landings and power supply. It may also have a bearing on the design of service ducts
the Building Regulations (England)
The regulations, (mostly Part KThe Approved documents, (England) part K, deals with Protection from falling, collision and impact. Included in this is staircase design), have a lot to say about stairs.
Below are extracts from the Building RegulationsThese are the mass of regulations that cover safety, health, welfare, convenience, energy efficiency etc. in the way buildings are constructed. Not to be confused with Planning consent (which is more to do with whether you can put up the building in the first place). See more on the regulations where stairs in houses are termed ‘Private stairs’
Because the relationship between the rise and the going is quite complicated there are 2 methods of achieving the correct result but they both rely on the fact that the pitch of the steps must not be greater than 42°.
This is how straight stairs are measured:
|The rise and going are limited as follows|
|minimum (mm)||maximum (mm)||minimum (mm)||maximum (mm)|
The two ways to calculate stairs are:
- The maximum rise for steps is 220mm and minimum goingthe going is the dimension of the horizontal depth of a step from its nosing back to the riseron a stair - the vertical part between the treads is 220mm (but of course with the added proviso that it will not be steeper than 42°)
- The other way is to make sure that the relationship between the dimensions of the rise and going is that twice the rise plus the going (2R + G) should be between 550mm and 700mm.
Straight stair calculator (England)
- Stairs are limited to 36 consecutive risers in a flight unless there is a change in direction. See para 1.14 in the Approved documentsApproved documents (England) are detailed publications which come under the English Building Regulations. They are based on tried and tested methods of building and if you follow them you are assured of complying with the Regs. The equivalents for Scotland are the Technical HandbookUnder the Scottish Building Regulations, the Technical Handbook gives construction principles, which, if you follow them guarantee compliance with the Regulations, for Wales: the Approved documents (Wales), and for N.I. the Technical BookletsUnder the Northern Ireland Building Regulations, the Technical Booklets give construction principles, which, if you follow them guarantee compliance with the Regulations.
- Risers are not allowed to exceed 220mm
- It is important to work to 0.1 of a mm. (or better) because cumulative error on many steps can become significant
- The greater the going the shallower the pitch of the stairs. You can’t have a combination of the maximum risers (220) with the minimum goings (also 220). It makes it too steep (over 42 deg). Longer goings make for shallower but longer stairs.
- If this result does not fall within 550-700 try adjusting the risers (via the number of risers) and the goings. The formula comes from the Building Regulations.
- if this is above 42 degrees then try increasing the going (or increasing the number of risers to make them smaller)
- The total length is the horizontal distance from the nosing on the top landing to the position on the lower landing directly below the lowest nosing. See diag. below
The 2000mm headroom rule can be reduced under certain circumstances for loft conversions. (see part K , page 8)
These calculations give you results as if there were no nosingsthe front edges of steps, which usually overhang the step below by a small amount on the treads. That is fine because you can simply add nosings to the steps afterwards without altering the basis of the calculations. However doing so will affect two things: both the headroom and the lower landing length will be reduced marginally.
The landing is determined by the regulations.
Headroom (with exemption for loft conversion)
A headroom of 2m is adequate on the access between levels (see Diagram 2). For loft conversions where there is not enough space to achieve this height, the headroom will be satisfactory if the height measured at the centre of the stair width is 1.9m reducing to 1.8m at the side of the stair as shown in Diagram 3.