The brief behind Endless Stair

The immediate fascination of a structure that visitors could inhabit was backed up by rigorous research that offered new potential for construction.

The Endless Stair, a timber installation that seemed to challenge the rules of perspective and which was installed outside Tate Modern in London in the autumn of 2013, took its inspiration from the drawings of Escher. But unlike the works of the Dutch graphic artist, whose designs were famously mathematically impossible, the Endless Stair was not only realisable but actually achieved. 

It consisted of a series of ‘handed’ timber stairs, some veering to the right and others to the left, offering a number of routes to a top flight that culminated in a viewing platform.

It was a great contribution to the London Design Festival. Equivalent to two-storeys in height, the network of stairs allowed visitors to enjoy the capital from different viewpoints, looking at the art gallery, the Thames river, the Millennium Bridge that crosses it and, on the other side, St Paul’s Cathedral. It also encouraged social interaction.

But it was much more than just a piece of art. The latest in a series of collaborations between the London Design Festival and the American Hardwood Export Council, it pioneered the use of hardwood in cross-laminated timber. A fast-establishing technology, cross-laminated timber is usually made from softwood, but AHEC believes that there is real potential for using tulipwood, a sustainably abundant, relatively inexpensive and structurally impressive American hardwood.

To test this idea AHEC worked on the Endless Stair with architect dRMM and engineer Arup, to create a design that was not only visually exciting but that also tested the potential of this new form of timber. Manufacturers in Italy and Switzerland made the elements, which were assembled quickly and efficiently on site.

Part of the thinking behind the project was a desire to make the elements as environmentally friendly as possible, with each flight of stairs built up from standard elements, as little waste as possible in construction and the ability to re-use and relocate the design either in part or as a whole. These laudable aspirations have been backed up by hard data, with a detailed life-cycle analysis (LCA) by expert organisation PE International, then the latest piece of work in AHEC’s ongoing mission to demonstrate the sustainable credentials of American hardwoods. 

Both the architect and the engineer expanded their knowledge in the course of the project. This means that the Endless Stair combined the visual excitement of an art installation with the seriousness and potential of a research project – a winning combination.