After reading chapter 2, I am almost convinced there are more elements that go into the making of a building than of a human. The author explains that there is a “conceptual system of order” that goes into the creation of a building. An idea behind the purpose and use of a building. Buildings are made up of structural, mechanical, and enclosure systems. The structural system serves as a skeleton of sorts. It holds the building up, with the use of columns, beams, and load bearing walls. The mechanical system can be compared to the “organs” of the building. This system consists of all plumbing, electrical systems, vertical transportation, and fire fighting systems. The last element is called the enclosure system and this serves as a protective layer, like the skin on a human. It regulates what comes in and out of the building as well as protects the mechanical and structural systems. 

          Doors, windows and exterior/interior walls are all a part of the enclosure system. The enclosure system allows us to egress a building. This action is critical to a building or any structure; as the placement of exits and openings help the flow of traffic in and out of the building. Another important, special structure is stairs. Stairs allow access to other floors in a building. I never knew the complexities of such a mundane structure. Elements of stairs include treads, risers, width, landing, handrails, guardrails, and nosings. The specifications and dimensions for the riser and tread I thought were interesting, as I have walked up uncomfortably steep and shallow stairs. There are a few different types of stair runs; six to be exact: straight, quarter turn, half turn, winding, circular and spiral. I agree with the author, in that winder stairs are the most hazardous. The tread on the interior of the turn are far too narrow.