Here's a photo of the staircase in my Winding Brook Road house. The stair treads and stringers are LSL (laminated strand lumber). LSL's are generally used as construction grade framing members and are not typically left exposed. I have found that when they are sanded and finished with an oil or urethane they have a beautiful and distinctive appearance. They are initially very rough and require a lot of sanding, but they are also very dense and strong (and therefore durable). The posts and railings for this stair are solid cherry, fabricated by a friend and colleague, Ruud Vekemans. The cables are 3/16" diameter stainless steel with simple and elegant tensioning hardware at the post connections. The outside wall of the stair tilts outward at the top and has a 20' tall insulated translucent window panel, manufactured by Kalwall. Natural light filters through the Kalwall and through the open stair into all levels of the house. At the top of the Kalwall panel there are two hopper windows that are left open from April to October. These windows in this tall open stairwell provide a natural chimney that vents warm air out of the house during the summer months. There is a ceiling fan that pulls air upward which assists this natural venting.