A Guide to Exterior Materials

Building materials are not only selected for their aesthetic qualities but must also function to keep out weather and be durable enough to stand the test of time. As architects, our jobs are to design a building with a focus on both form and function while creating a solution for the design problem. A building’s form may be shaped by its surrounding environment, cultural influence, or climate. Its function however still needs to maintain the material characteristics that are durable, sustainable and available. Five of the most common building materials which encompass all of these characteristics are brick, concrete block, metal, concrete, and glass.

Brick is one of the oldest known building materials dating back to a time where they were made of mud and dried in the sun. They are now more commonly made of clay and can be made into many different shapes sizes and come in a wide range of colors. This is a popular choice as an exterior building material due to its durability, flexibility in design, color options, sustainability, weather resistance, and availability. Bricks are typically installed as a veneer but have the capacity to be used in multiple withes to stand alone as a structural wall. Veneer units are constructed in front of either a metal stud or concrete block wall and can be projected or recessed to create different patterns on the face of the wall.

Concrete block can be used as a structural wall material or have an exterior finish face depending on its function. Exterior concrete block also has a range of color and texture options beyond standard gray block. Options could be a split faced product which has a course face and provides a lot of nice texture or a smooth face which is ground down and burnished to create another finish option. Concrete block is modular and courses out with brick and other masonry products to give a designer many options for patterning and flexibility. The blocks are reinforced with steel both horizontally and vertically and make for a sound option for an exterior building product.

Metal is used in many forms in building design: structural steel, ornamental decoration, building cladding, roofing materials, and construction hardware to name a few. Decisions to use metal as an exterior building skin are made to express a texture or color desired by the designer. These materials can come in panels of the natural finish metal itself, for example copper and zinc, or can be an aluminum product that is painted from a wide range of colors. Other design options will allow for rolling and shaping the metal panels to have ridges or waves or corrugations which create interesting textures.

Concrete is widely used throughout the construction process in floor slabs, wall design, foundation work, roofing, and can be cast into many different shapes. Concrete has the flexibility of finishes from smooth as glass to a rough broom finish texture which would most likely be used on a side walk. Concrete walls or tilt-wall construction are installed in panels that are pre-cast and then erected onsite. The panel forms can be lined with gravel or patterned with templates to create textures on the wall panels before they are installed. Paint or stains can also be used to add color and creative designs.

Glass is a product used on almost every project and can be a full wall, window, or door on the exterior of a building. Exterior glazing is designed with properties to repel heat which will keep the heat in the building during the winter and outside during the summer. Most commercial glazing is also double paned and insulated to help with the problems of solar heat gain to keep the building cool. Glass can be tinted in colors ranging in the greens, grays, and blue classes and films can be applied to achieve an ever broader range in colors.

Choosing products for the exterior skin of a building happens at the beginning of design and is a critical decision. Durability, sustainability, and maintenance are just a few of the common requests from building owners that are relayed during the beginning discussions with the architect. Brick, concrete block, metal, concrete, and glass are common building products that are widely used, readily available, and will maintain function while still allowing for good design.