South Kensington: Fibonacci Marble Staircase

This project came from a designer with a brief rooted in the Fibonacci spiral. The staircase at this private residence in South Kensington was to be clad entirely in Breccia Oniciata marble with the veining running continuously across every tread, every riser and the curved newel post base at the foot of the staircase, as though the whole structure had been carved from one piece. It had been. Every element came from a single slab. There was no second slab to fall back on. Every cut had to be right first time, in the right sequence, or the veining continuity that made the whole project worth doing would be lost.
The curved newel post base made the geometry significantly more demanding than a standard staircase. Its profile could not be taken from a drawing alone. It had to be templated by hand on site, with paper templates made to capture the exact radius before any stone was touched. Engineering drawings were produced for the full staircase covering tread depths, riser heights, the Fibonacci spiral plan and the section detail of every curved piece. The stone was then cut and polished on site throughout the two-week programme. There was nowhere to send it back to if something went wrong.

Laser levels were used at every stage of the installation to confirm that each tread sat at the correct height and pitch and that the joints between pieces were consistent from the bottom of the staircase to the top. The veining was sequenced from the single slab so the movement in the stone carries through each tread and riser without interruption. The circular newel post base at the foot reads as a natural continuation of the same stone rather than a separate piece placed beside it. That is the effect the brief called for and it only works when the cutting sequence is planned and executed correctly from the start.
The finished staircase carries the Breccia Oniciata veining continuously from the ground floor landing to the upper level. The brass handrail and black metal balusters above sit in considered contrast with the warmth of the marble below. It is the kind of project that does not come along often and the kind that stays with you once it does. We are proud of how it came out.