Meeting the Challenges of Planning Policy for Wind Microclimate of High-rise Developments in London

In the drive to contain urban sprawl and the desire to promote sustainable urban development that enhances the quality of inner city life, urban regeneration in London and in other major cities of the United Kingdom (UK) is facing ever more stringent scrutiny by planning authorities. With increasing emphasis on recreational use of outdoor areas in the vicinity of major urban new-build developments, designers and developers are facing up to the need to shape the external wind microclimate to ensure suitability for future use of open spaces and to deliver a low impact on public areas within the vicinity of the site. In the UK, tall buildings are drawing the attention of planning authorities like no other type of development due to their potential to cause downdrafts of fast upper-level winds, strong flow accelerations around building corners and funneling between neighbors. Planners expect to see due consideration from an early stage, not only via a comprehensive and robust wind assessment but also by demonstrating inbuilt design measures that offset or even prevent unacceptable impacts within an existing 'present-day' context plus, importantly, within a future context where other equally tall structures are expected to emerge. This technical paper will document the challenges of the planning process for wind assessment of tall buildings in the UK and in particular discuss the requirements of Environmental Impact Assessments (EIA) and the intricacies of wind engineering approaches that support this process.