In homes with decks and outdoor-living spaces, patio doors can be real workhorses. The need to operate effortlessly, be energy efficient, repel pests and weather, and be attractive. In this article, associate editor Patrick McCombe takes a look at what you need to consider when choosing a patio door. All patio doors should meet certain performance criteria (multipoint lock and specific U-factor and solar heat-gain coefficient standards). Hinged and sliding patio doors then have their own sets of performance criteria, including locks and screens. Other choices to make include swing vs. sliding doors and doors vs. foldaway walls. Patio doors also come in a variety of materials, such as aluminum, fiberglass, steel, vinyl, and wood.