Owing to wind tunnel risks City of London introduces stricter rules on skyscrapers

The city of London has ordered new guidelines for skyscrapers owing to the concern that high-rise and urban microclimate could generate winds which are capable of knocking over pedestrians and cyclists.

The tougher rules will need developers to provide a comprehensive safety assessment of building proposals, stating its effects on street people. Furthermore, a more accurate testing of pavements and roadways will be created with the help of detailed scale models in computer simulations and tunnels.

The new rule will also reduce the level of wind conditions which are deemed as tolerable according to the guideline. It will hence also reclassify average wind speed of more than 8 meters per second (18 mph), which will be considered uncomfortable. This will further also put pressure on developers to mitigate plans which will not affect pedestrians and cyclists.

The tough guidelines will hence require an evaluation of wind impact at the very beginning of the design development. It will also require a micro-level test from 36 wind directions, which will require separate consultants for physical and computer simulations. Vulnerable spots near schools, parks, hospitals and in the vicinity of Thames will especially require special examining.

The city has witnessed a host of skyscrapers in the recent years. Leadenhall Building, also known as the “Cheesegrater”, and the “Walkie-Talkie” at 20 Fenchurch Street are some instances. While six are under construction, 13 new skyscrapers are expected to by 2026. These will allegedly range from 78-305 metres.

A spokeswoman for the City of London Corporation said in connection to the new guidelines; “closely monitoring high-rise buildings, including the Walkie-Talkie, to ensure wind conditions in the surrounding streets remain stable”.

The new rule was appreciated by Cycling groups of London. There is a “well-documented risk of concrete canyons … creating wind conditions where pedestrians can be knocked off their feet or cyclists can be pushed sideways into the path of motor vehicles”, commented  Simon Munk of the London Cycling Campaign.