San Franisco, Paulo Alto, helical staircase in wood

This is a particularly nice staircase we have built for a private residence in California, the sun shine state of the US. 
Connecting three floors this helical wood veneer finish staircase has a sculptural appearance. The underside of the staircase contains a sprinkler system so that the all wood staircase can still be used in case of a fire. 
Structural wood staircase have many advantages towards steel constructions. The material is way lighter and it is easier to build a wood finished staircase in all wood, rather than having a steel core which need to be wrapped on all sides. 
 

See the video here