Policies and Technical Guidelines for Urban Planning of High Density Cities – Air Ventilation Assessment (AVA) of Hong Kong

In 2003, Hong Kong was hit by Severe Acute Respiratory Syndrome (SARS) from which many peopledied. The Hong Kong Government subsequently set up a Governmental Team Clean Committee toinvestigate possible urban design policies. Team Clean charged the task to the Planning Department,HKSAR. It initiated a study titled: Feasibility Study for Establishment of Air Ventilation Assessment(AVA) System. In 2003, the research contract was entrusted to a team of researchers of Departmentof Architecture, CUHK. A number of focused studies were conducted. It eventually led to thetechnical methodology of Air Ventilation Assessment (AVA). Unlike many countries with guidelines fordealing with gust wind problems, AVA is a guideline for weak wind conditions specifically designed todeal with congested urban conditions. The AVA system basically establishes a method for projectdevelopers to objectively assess their designs. In 2006, the Government of Hong Kong has officiallyadopted the system and will require all major development projects to undertake the assessment. Thescientific and implementation processes leading to the AVA system is reported in this paper.