Light streams deep into the lower ground floor space from the double-height windows on the rear elevation, sprinkling light between the treads of the stairs and casting shadows on the walls. The stairs' treads come tantalisingly close to the wall, but they don't touch it.
The clients’ growing collection of art and their ever-evolving love for it have followed them back and forth across the globe. It's no coincidence that the high ceilings and white walls within Doorzien House, reminiscent of an art gallery, are among their favourite features, including this wall along the stairs.
The stairs were not finalized when the builder started construction on the house. There was an ongoing discussion about the artwork and how the wall along the stairs was going to be used. The general consensus was to keep the stair separate from the wall. During a discussion about the required size of the stringer adjacent to the wall, I suggested we could try to make it as small as possible. As I was discussing it in a design meeting, I suddenly came to the realization that we might be able to delete the stringer altogether. All we needed to do was cantilever the treads from the stringer on the other side.
So that is exactly what we did. The treads of the stairs cantilever off a stringer that extends down the inside line of the stairs. Glass acts as a balustrade for the stairs and extends up to the first floor, where it also acts as a balustrade.
The vibration of each tread was the critical component of the stair design. And I approached this very delicately. As I describe to the client, while walking up or down the stairs, you will almost certainly not feel any movement. You are in motion as you move down the stairs. If the stairs move, the movement in the stair will just be perceived as part of your motion. However, if you stand on the stairs while someone else goes up and down the stairs, you can feel each footstep. But how often does that happen? The clients agree that this would be rare. So we engineered each tread to experience a small amount of perceived movement in line with this reasoning. We then collaborated closely with the builder, architect, steel fabricator, and client to determine the appropriate stiffness for the stairs.
The decision allowed us to maximize the amount of light coming through the stairs. This permits light to penetrate deep inside the lower rooms of the house, which do not experience any natural light otherwise.
