Which type of material is commonly used for structural framing?

Wood is commonly used for structural framing due to its favorable strength-to-weight ratio, availability, and ease of handling and installation. It provides good insulation properties and is a renewable resource when sourced sustainably. Wood can be pressure-treated or engineered to enhance its properties, making it suitable for a variety of building applications, including residential and light commercial structures.

The other materials mentioned, while they have important roles in construction, are not primarily used for structural framing. Glass, for example, is typically used for windows and facades rather than as a framing material. Brick serves as a masonry unit for walls but does not function as a framing element. Plastic is used in specific applications, such as piping and some exterior finishes, rather than for structural integrity in framing. Therefore, wood stands out as the best choice for structural framing in construction.