Old House, Spiral Staircase
Architect: tonkin liu
Client: Clockwork Farms Ltd
Structural engineer: Rodrigues Associates
Main contractor: Suncomfort Ltd
Wood supplier: Altripan UK Ltd
Wood species: Russian birch ply
A new spiralling CNC-machined staircase provides access to the upper storeys of the 16th century Grade II* Listed Old House. The spiralling plane along the inside of the stair is formed of four layers of flexible plywood, a compression spiral supporting the stair over two storeys. The spiral also provides outward thrust which is transferred through the treads and risers into the vertical planes of the surrounding building. The walls are formed of vertical planks of birch plywood, aligning with the treads of the stair which rest on the top edge of the wall planks below. The entire kit was assembled from bottom-up. As the next wall plank was fixed in place, the treads were locked in position to provide a strong and stable connection, bracing the walls of this historic stair tower to the modern birch plywood spiral.