What are doors made of in Canada?

In Canada, exterior and interior doors are made of several materials suited to cold climates, energy efficiency, and durability, similar to the US but with emphasis on insulation. The most common material for exterior doors in Canada is fiberglass, which is very popular because it resists warping, does not rot, insulates well, and can mimic wood grain while withstanding extreme cold and moisture. Steel doors are also very common for exterior entry doors in Canada, especially in Ontario and Quebec, because they are affordable, secure, and energy efficient with foam core insulation, often used in new construction. Wood doors are used for premium homes, usually with aluminum or fiberglass cladding on the exterior to protect against weather, with solid wood interior for aesthetics. For interior doors in Canada, the most common materials are hollow-core molded MDF or Masonite, which are lightweight and affordable, and solid-core MDF or wood for better sound insulation and premium homes. Sliding patio doors are typically vinyl or fiberglass framed with double or triple pane low-E glass for energy efficiency. Canadian building codes require high energy performance, so doors often have Energy Star certification, triple pane glass inserts, and insulated cores. So in Canada, exterior doors are mainly fiberglass and steel, interior doors are mainly MDF and wood.