Willingness to pay for improved environmental performance of the building envelope of office buildings in Hong Kong

This study examines the amount of money that designers and developers are willing to pay to improve different aspects of the environmental performance of exterior envelopes by using office buildings in Hong Kong as an example. A method modified from the averting expenditure approach was applied to 16 office buildings built or tendered between 1999 and 2001. Our results show that the designers and developers considered the provision of an appropriate sensation index of outdoor connection (or window to wall ratio) for building envelopes was far more important than improvement of the environmental performance when the interiors of their buildings were open to a view showing them surrounded by other office buildings. Improvement in thermal performance of building envelopes would be considered only if an appropriate window-to-wall ratio had been fixed. Application of the method has successfully shown the amount an individual developer will invest and a designer's willingness to pay to improve the performance of a building envelope. The methodology should be able to be extended to other building elements, components or systems after some modifications.