Few sights are more likely to send environmentalists into fits of apoplexy than that of open shop doors that allow hot or cold air to spill out onto the pavements. But such energy profligacy looks set to become a thing of the past for one of the world's most famous shopping destinations, after New York Mayor Michael Bloomberg last week passed legislation banning many stores from leaving their doors open during the summer.

Under the new rules, commercial establishments such as shops and restaurants will no longer be banned from leaving street doors open while operating their air conditioning – a common practice designed to tempt sweltering passers by into the store during summer months.

Bloomberg said that the legislation would fit into the city's PlaNYC initiative to cut the city's greenhouse gas emissions by 30 per cent and also help reduce peak demand levels on its electricity grid. He added that only stores that are less than four thousand square feet in size and not part of a chain, and also restaurants that open on to sidewalk cafés would be exempt from the new rule.

US green group the Natural Resources Defense Council (NRDC), which helped draw up the legislation, said that a business with a typical six foot by seven foot doorway in New York wastes up to $1,000 dollars and around a tonne of CO2 each a summer by leaving its door open with the air conditioning on.

"The Long Island Power Authority has estimated that stores engaging in this practice waste 20 to 25 per cent of the air-conditioning they use," observed director of the New York urban programme at NRDC, Eric A. Goldstein. "This practice is foolish – it inflates these stores' electric bills and it puts city neighbourhoods at an increased risk for blackouts."

The NRDC added that it hoped the legislation would become a template for other municipal governments across the US and beyond, as they seek to cut energy use and curb carbon emissions.

A spokesman for the British Retail Consortium rejected the suggestion that similar legislation was required on this side of the Atlantic.

While he accepted that the issue was likely "to surface again this coming winter" as stores continue to keep doors open even when heating their floor space, he insisted the problem was not as severe as many observers believe.

"A lot of premises use air curtains that act as invisible barriers for keeping the warm air in the store," he said. "We're not in favour of legislation, as it is already in retailers' interest to ensure stores are as energy efficient as possible… and studies have shown that closed doors do discourage shoppers from coming in, which in tough economic times is not something anyone wants."