A parking ratio is a number of parking spaces per unit of a variable like square footage, number of seats in a venue, bedrooms, and so forth. Many regions set minimum and maximum ratio as part of their development and transit policies. Landlords without sufficient parking may be able to apply for a variance if it is a legacy of a prior era, but often need to update their parking if they want to perform work on the property such as tearing a building down and building a new one. Information about the current parking ratio laws should be available through the city government.
Parking ratios serve a number of functions. Minimum ratios are supposed to ensure that there is enough parking available for everyone to use. In a city with limited street parking for instance, mandating an off-street space for every bedroom may be part of a plan to free up spaces on the street by having residents park off the street. At a business, enough parking to serve patrons should be available. The parking ratio can also include a mandate for accessible parking, usually in terms of a wheelchair-accessible space per set number of parking spaces for disabled patrons.
On the maximum end, the parking ratio may also work to prevent congestion and encourage the use of public transit. If the only available parking is limited and expensive, commuters may turn to other options for getting to work. These can include car and van pooling, taking the train, and so forth. This will reduce the amount of traffic in a city core and can cut down on environmental problems. Some cities around the world enacted retroactive maximum parking ratio laws in the 1990s and early 2000s to address these issues.
When developers propose to build new facilities, including homes, businesses, workshops, and so forth, they usually also need to show plans for parking. These should incorporate information about the current parking ratio and the planned uses of the property. For a movie theater or concert hall, the ratio is often based on the number of seats, while retail buildings typically have a ratio based on square footage. The developer should be able to estimate these factors accurately and provide enough parking to meet the need.
It may be possible to apply for a zoning variance if the number of spaces will not meet the parking ratio. The landlord must show why this is necessary. One example might be that of a building on an irregularly sized lot, where the lot is not quite large enough to add parking without substantial construction work like creating an underground parking area.