Multistorey car park

A multistorey car park (Commonwealth English) or parking garage (American English), also called a multistorey, parking building, parking structure, parkade (Canadian), parking ramp, parking deck, or indoor parking, is a building designed for car, motorcycle, and bicycle parking in which parking takes place on more than one floor or level. The first known multistorey facility was built in London in 1901 and the first underground parking was built in Barcelona in 1904 (see history). The term multistorey (or multistory) is almost never used in the United States, because almost all parking structures have multiple parking levels. Parking structures may be heated if they are enclosed.

Design of parking structures can add considerable cost for planning new developments, with costs in the United States around $28,000 per space and $56,000 per space for underground (excluding the cost of land), and can be required by cities in parking mandates for new buildings. Some cities such as London have abolished previously enacted minimum parking requirements. Minimum parking requirements are a hallmark of zoning and planning codes for municipalities in the US. (States do not prescribe parking requirements, while counties and cities can).

The earliest known multi-storey car park was opened in May 1901 by City & Suburban Electric Carriage Company at 6 Denman Street, central London. The location had space for 100 vehicles over seven floors, totaling 19,000 square feet. The same company opened a second location in 1902 for 230 vehicles. The company specialized in the sale, storage, valeting, and on-demand delivery of electric vehicles that could travel about 40 miles and had a top speed of 20 miles per hour.

The earliest known parking garage in the United States was built in 1918 for the Hotel La Salle at 215 West Washington Street in the West Loop area of downtown Chicago, Illinois. It was designed by Holabird and Roche. The Hotel La Salle was demolished in 1976, but the parking structure remained because it had been designated as preliminary landmark status and the structure was several blocks from the hotel. It was demolished in 2005 after failing to receive landmark status from the city of Chicago. A 49-storey apartment tower, 215 West, has taken its place, also featuring a parking garage. When the Capital Garage in Washington, D.C. was built in 1927, it was reportedly the largest parking structure of its kind in the country. It was imploded in 1974.

The movement of vehicles between floors can take place by means of:

Where the car park is built on sloping land, it may be split-level or have sloped parking.

Many parking structures are independent buildings dedicated exclusively to that use. The design loads for car parks are often less than the office building they serve (50 psf versus 80 [100] psf), leading to long floor spans of 55–65 feet that permit cars to park in rows without supporting columns in between [called long span]. Podium parking below high-rise and mid-rise buildings are often short-span 25–30 feet clear between columns, since office/residential/retail floors above require more support [100 psf per International Building Code]. Columns in short -span structures obstruct row based parking spaces and will be less efficient than long-span designs; parking efficiency is measured in cars per level square footage [car count/level area]. Common structural systems in the United States for long-span structures are prestressed concrete double-tee floor systems, post-tensioned cast-in-place concrete floor systems or short-span podium parking with post-tensioned slabs and drop panels [drop heads. Steel embeds or thicker slabs can eliminate the need for drop panels, providing higher clearances for higher profile vehicles.]

In recent times, parking structures built to serve residential and some business properties have been built as part of a larger building, often underground as part of the basement, such as the parking lot at the Atlantic Station redevelopment in Atlanta. This saves land for other uses (as opposed surface parking), is cheaper and more practical in most cases than a separate structure, and is hidden from view. It protects customers and their cars from weather such as rain, snow, or hot summer sunshine that raises a vehicle's interior temperature to extremely high levels. Underground parking of only two levels was considered an innovative concept in 1964, when developer Louis Lesser developed a two-level underground parking structure under six 10-storey high-rise residential halls at California State University, Los Angeles, which lacked space for horizontal expansion in the 176-acre (0.71 km²) university. The simple two-level parking structure was considered unusual enough in 1964 that a separate newspaper section entitled "Parking Underground" described the parking lot as an innovative "concept" and as "subterranean spaces". In Toronto, a 2,400 space underground parking structure below Nathan Phillips Square is one of the world's largest.