Canopy businesses supply, make and install covered structures that provide shelter from sun and rain. Products range from fabric awnings fixed to buildings to freestanding or wall-mounted canopies over doors, patios, walkways and outdoor seating areas. Some designs are retractable, allowing the covering to be extended or folded away, while others have a permanent frame with fabric, polycarbonate, glass or metal roofing. Services may include measuring a site, advising on suitable materials and fixing methods, and fitting the canopy to a home or commercial premises. Businesses may also provide replacement covers, repairs, cleaning and maintenance. Larger projects can involve entrance shelters, covered links between buildings, smoking shelters or canopies for shops, schools and hospitality venues. The frame, covering and installation requirements depend on the intended use, exposure to weather and the building or ground to which the structure will be attached.