Loft stair by deDraft
Loft conversions are a great way of adding extra floor area to your home. To ensure a successful project, it’s vital you get the positioning and design of the new stair right. If poorly thought through, it can have an undesirable effect on both the new loft space and existing layout below.
A well-designed loft conversion stair will not only ensure the layout works efficiently but add a sense of light and space and increase the desirability of your home.
Loft conversions are often the domain of design and build companies with limited design expertise. In the guide below, we offer a more design-focused approach and include information on stair types and configurations, building regulations rules and design advice.
We hope you find it both useful and inspirational.
More:
Dormer loft conversions – an architect’s guide
23 Loft conversions by designed by architects
UK loft conversion costs: analysis and money saving tips
Ideally, the new loft stair should sit over the existing stair and form a continuation of the vertical circulation from top to bottom through your home. The reasons for this are threefold. One, existing rooms are not compromised. Two, it’s better for fire regulations – more below. And three, it reduces circulation, thereby freeing up more space for useable floor area.
If continuing the existing stair is not an option, you can still make a new loft stair work. You will just need to reconfigure more of the existing floorspace below and form additional circulation.
If you can only access the roof void via an existing room, and not a stair landing, consider building a mezzanine level instead. It’s often a better use of space.
New contemporary stair over a Victorian staircase by Aron Coates of Designs in Detail
Straight Flight. For conventional loft stairs you have a few configuration options. A simple straight flight is the simplest and most economical to build.
Straight flight with winders. Introducing winders at the top or bottom of a stair flight enables you to gain height quicker and within a more compact floor area. Take a typical Victorian terrace loft conversion stair as an example. Adding winders at the top and bottom allows the stair to clear the existing flight below and reach the new loft level before the back wall of the house.
Dog leg stair. Introducing a half landing and returning the stair in the opposite direction creates a dog leg stair. If space permits, this is most desirable configuration as it is comfortable to use and creates a sense of spaciousness. Adding winders to the flights or landing offers space and height options, as above.
Loft stair configurations (non-exhaustive), image by Designs in Detail
If you don’t have the required headroom to install a staircase, the most common solution is to add a roof dormer to increase the ceiling height. Roof dormers come in many different styles and need to be sized to meet planning or permitted development requirements.
If the lack of headroom is because of an existing hipped roof, consider a hip-to-gable extension to add more internal volume. Here, the end section of roof is removed, and the ridge extended to form a new gable end.This is generally only an option if your home has permitted development rights and can be difficult to achieve through full planning permission.
If only a marginal height increase is needed in a localised area, simply installing a rooflight may be the answer. You can gain anywhere between 100 to 200 millimetres depending on the roof thickness.
If planning or layout constraints mean a conventional loft conversion stair is not feasible, consider a space saving stair – more on this below.
Roof extension options to gain more headroom, image by Designs in Detail. A rear dormer could be added to Option C for a larger roof volume.
Conventional stairs take up a lot of room and are not possible in some homes. If space is at a premium, consider one of the following options:
Note, space saving stairs can only be used in loft conversions if there is only one habitable room in the converted roof space (the addition of an ensuite is allowed). They should not be proposed for people with impaired mobility.
Left: Ash veneered spiral stair by 51 Architecture. Photo by Jim Stephenson
Right: Birch plywood alternate tread stair by Proctor Shaw, Photo by Ståle Eriksen
When converting a redundant roof space into a habitable area, the works need to comply with building regulations. The main rules for a stair when adding a loft floor to a two-storey house are as follows:
There is no minimum width for loft conversion staircases, but they should be comfortable to use and allow for the moving of furniture.
Loft stairs form part of the means of escape out of the building which needs to be fire protected. This can be achieved by ensuring all walls, floors and ceilings forming the stair enclosure are 30 minutes fire resistant. All doors to habitable rooms (not bathrooms) should have FD20 fire doors as a minimum.
Buildings with a top floor 7.5 metres above external ground level, for example existing three-storey houses, may require a second means of escape or added protection such as a mist system.
It is important to seek advice from an architect or building control before commencing you loft conversion works to ensure it complies with the building regulations and avoid costly delays and uncertainty.
Also refer to Part K of the building regulations for further information.
Loft stair building regulation dimensions (non-exhaustive), image Designs in Detail
Part B of the building regulations, which sets out the means of escape from buildings in the event of fire, prescribes that domestic stairs should be enclosed by fire protecting construction. To create an open plan layout, you need to get creative, which may require the input of a fire engineer.
The simplest way to open up a stair to a habitable room and meet building regulations is to install a fire rated pocket door - a type of door that can slide into the wall to form an unobstructed opening. Large, clear openings can be achieved by installing double pocket doors. You will need sections of wall for the door to slide into (the pocket), so the space will not be completely clear.
The other option is to install a mist system. Combined with a fire strategy report from a qualified fire engineer, you can achieve completely open plan spaces. Note, you may also need to factor in an alternative means of escape (possibly including a first floor window), additional protection measures and warning systems.
Seek specialist advice before carrying out this type of work.
Stairs with sliding pocket doors off landings by William Tozer Associates
The spaces below loft stairs can be dark and uninviting. To increase natural light, think about the positioning of external glazing and opening up the stair construction.
Installing a rooflight above the stair is an obvious suggestion, but frequently overlooked. Rooflights provide about twice as much daylight as a window through the same sized aperture and even a small unit will flood natural light into the space. To keep costs and delivery times down, choose an off-the-shelf product.
A standard loft stair flight can block daylight reaching the floor below. To alleviate this problem, consider installing open risers or perforating the construction to allow light to pass through. Paint the walls, ceilings and stairs light colours so the light reflects down.
Left: Perforated steel stair by Fraher & Findlay and Zed Works, photo by Chris Wharton
Right: Open riser stairs with rooflight above by William Tozer Associates
In older properties with an attractive traditional staircase, a common approach is to match the new loft stair with the existing one. In practice, however, this is very difficult to achieve.
Take a Victorian stair as an example. Many of the standard timber mouldings and profiles produced today are unlikely to match the original design and you will need to appoint a specialist to produce bespoke parts.
Further, Victorian stairs are usually free of winders and have a continuous moulded handrail running from start to finish. Loft stairs typically include winders and need a newel post to support the new handrail. This means the existing handrail needs to be cut to suit the new stair which effects the quality of the original design.
The end result is often a poor pastiche of the original.
In many cases it’s best to embrace the fact that the new stair needs to be different. A new contemporary stair can mark the end of your old house and the start of something altogether different above.
Left: Modern painted stair over Victorian stair by Aron Coates of Designs in Detail
Right: Modern timber stair over 1930s stair by StudioSH, Photo by Lorenzo Zandri
Embracing the idea of installing a contemporary stair frees up a world of possibilities.
Loft conversions stairs can be constructed from timber, plywood or metal. They can be painted, stained or varnished. Storage and shelving can be integrated into the design. Balustrades can be formed in solid panels, narrow sections, or rods and can continue up to the ceiling. Stair flights can be cantilevered, traditionally supported at both sides or suspended from above. Plywood stairs can be CNC manufactured and cut to form highly individual designs.
The options for creativity are almost endless.
More: 23 loft conversions designed by architects
Left: CNC plywood stair by Tsuruta Architects, Photo by Tim Crocker
Right: Perforated steel staircase by Architect Tim Pettigrew, fabricated by Zed Works
Stair costs depend on the type of stair, complexity of the design and specification.
A standard loft conversion staircase constructed in off-the-shelf pine components and assembled by a stair subcontractor is the most economical. Little thought is put into the design. The main goal is to get from A to B.
Simple CNC manufactured plywood staircases offer more creative possibilities at only a slightly higher cost.
Bespoke staircases not only cost more in terms of materials and labour but also incur higher design fees.
As a rough guide, expect to pay the following for the various options, fully installed:
Plywood loft staircases by Bradley Van Der Straeten, photo by French+Tye
About the author: Aron Coates is an architect with over two decades of experience, encompassing projects ranging from the restoration of historic buildings to the design of contemporary homes.
The information provided in this article is intended for general guidance and educational purposes only. At Designs in Detail, we advise you appoint a skilled residential architect to provide specific expert advice for your project.
