Helical Stair

Written By

Paul Sutton

22.6.2021 Thinking

Paul joined Page\Park in 1993 with 12 years post qualification experience as an architect.  Since then his role has expanded from project architect for numerous schemes to consolidation of the theoretical base of the practice.

He has been instrumental in the firm’s drive constantly to improve the quality of projects for our clients, users and for society as a whole.  Over the last ten years he has been driving the implementation of Building Information Modelling focused on the use of Autodesk Revit by the practice.  He is currently a director with specific responsibility for design philosophy, technical support and IT.



I would like to describe an example of what I love about the practice of architecture – the art of construction.

Something interesting happened while building work was taking place to implement our designs for the transformation of the Charles Rennie Mackintosh designed former Glasgow Herald Building into the Lighthouse. The Contractor removed the old sprinkler tank and floors in the corner tower, opening up its full height from third floor upwards – some 28 metres.  We walked in with the client and agreed that we had to find a way to get people in to enjoy this magnificent space. The rough stone construction was like a cliff rising up to a hidden arcade and the bell shaped roof at the top.  What about a helical stair hanging from the roof, without touching the sides of the tower?  A helix would be better than a spiral because it would be open in the centre

We began to explore a design for this stair using 3d modelling so we could visualise it as it developed.  It was thrilling to be designing inside this beautiful structure which Mackintosh had laden with symbolic meaning (see the article on the Lighthouse on our website)  We decided that the stair structure was to be of steel for lightness, with oak steps and landings and stainless steel handrails.  The stair was to be hung from stainless steel rods attached to a new steel beam structure at roof level since the timber roof structure could not take the load.  Lighting of the space was by fittings carefully placed to show off the stonework to best advantage, with cables hidden in the mortar joints between the stones.  Double stringers were placed at the middle of the steps so the step edges could be as slim as possible.  The required emergency lights were designed into the underside of the landings with the conduit supplying them running up between the double stringers on the centre line of the steps.  The steps were to be solid oak supported on steel plates.

We realised that it would be most important to find the right people to make this stair as we would need to collaborate with them on the detailed design.  After discussions with several specialist fabricators we chose Annandale Design.  They added a great deal to the quality of the finished article.  For example with them we developed a slim handrail support which ‘grew’ out of the steel baluster.  A stainless steel rod welded to the underside of the handrail was let into the baluster top and secured with a flush allen key fitting.  The balustrading was a perforated steel mesh, chosen for its transparency, a high percentage of free area.  Large panels were edged with a pressed channel and bent to the required curves.  For the oak steps and landings we chose Telfords Fine Furniture who recessed the steel plate supports into each step so only oak showed on the edges of the stair.

This short summary touches only a fraction of the fascinating detail of this process of making, where there is no hard line between design and construction.

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