The city civic authorities have relaxed building rules governing both residential and commercial structures to create more parking space, which can be let out commercially.

The new rules that came into effect last week state that extra parking space in a new building will be excluded from the permitted covered area, or floor area ratio. But the plot owner will have to pay the sanction fee for the total parking space and will not be allowed to encroach on the mandatory open space.

The earlier rules — framed in 1980 — had set a limit on the parking space, which depended on the size of the plot and the width of the road in front of it, among other factors.

To create space for each extra car, the owner or the developer had to forego 200 sq ft from the covered area.

The new rules allow parking space beyond the floor area ratio to be set up from the basement to the first floor of a building.

“The city is badly in need of more parking space. The new rules will offer an incentive to plot owners and developers to create more space for vehicles in residential and commercial buildings. The space can be used commercially,” said municipal commissioner Alapan Bandyopadhyay.

According to a civic estimate, of the 300,000-odd cars that hit the street during peak hours, around 100,000 are in search of parking space at any time. “Around 10,000 cars are kept on the roads or in parking plazas and another 20,000 in offices and residential buildings. Which means, there is no space for as many as 70,000 cars. The new rules will help ease the situation,” said a civic official.