Norwegian architect Tron Meyer has designed a spiral staircase made entirely from laminated wood carved into curving steps that optimise the space for walking on (+ slideshow).

Tron Meyer's Risa staircase rethinks a familiar architectural feature as an engineered product, manufactured from a single material and designed to offer a sustainable alternative to more standard designs.

"Spiral staircases today are mostly made in concrete or steel, so it was interesting for us to ask how it would work as a construction in wood, contrary to a wooden surface on a steel or concrete stair," Meyer told Dezeen.

Referencing Norway's heritage of building in wood, the staircase is produced from cross-laminated timber that is layered and milled into precise profiles using computer-controlled machinery.

Three of these sections combine to make each step, with the lower layers carved in a concave shape that increases the surface area of the tread close to the central column.

"We looked at conventions like the narrow part of the step along the core, and asked us how we could make it into a valuable part of our design," explained Meyer.

"The staircase becomes a balanced dialogue between absolute needs of function and an optimal construction using wood."

As well as increasing the area for walking on, removing curved sections from the lower profiles reduces the weight of the structure and the amount of material used.

The layered formation of the steps creates the impression of a solid cylindrical column at the centre of the structure.

Steps fan out from the core, with their uniform undersides producing a sculptural surface of ribbed layers.

The staircase is designed and distributed by the architect's company Risa Meyer, and is produced in Norway from locally sourced timber to allow the entire process to be streamlined and sustainably managed.

Risa can be specified in pine, spruce, ash and oak and is assembled on site from standard pieces in configurations that can be customised to the spatial requirements.

"We chose materials that combine strength, surface and colours that meet our standards of quality," added Meyer.

"To us, wood is a kind of magical material with a great variation of qualities, grown straight from the ground."

Photography is by Rumi Baumann.