The second prominent material on the exterior following the fiber cement is cor-ten steel. Cor-ten steel is a weathering steel which has, in recent years, become part of progressive architecture’s material palette.
Cor-ten steel was developed to eliminate the need for finishing or painting. The material develops a thin outer layer of rust upon interaction with the elements which, in turn, protects the remainder of the material from erosion. This is what is so great about the material. Over the first few years, you get to actually witness the process of rusting occur. You see the material develop this outer layer of protection, which becomes a beautiful rust color.
The use of cor-ten as a cladding material has become popular in recent years, with many prominent projects using it as well as a number of residential projects. Here are a few just to give you a sense of its finished appearance.
Here is an image before and after the rusting process from the Parish Church of Santa Monica by Vicens & Ramos:
You may also be familiar with cor-ten through the work of Richard Serra:
In the design, there are primarily two zones which will be clad in the cor-ten. Two sections on the west wall and the dining box on the east side of the house. Both allow you to experience the material up close, from the patio out back, on the west balcony, and at the entry on the northwest. As you enter the front of the house, you will move past the polycarbonate on your right and the fiber cement on the left and the cor-ten surrounds the entry door. You experience virtually all cladding materials in that small sequence, in a good way.