Abstract: Fire load survey data can provide a basis for the development of fire protection design codes and building performance-based design. In order to expand the existing database, a fire load survey of 27 offices (11 university offices and 16 commercial offices with a total area of 3 130 m2) in Hong Kong and Mainland, China was conducted in this study using a machine vision-based digitized survey method. The average fire load density of the investigated offices was （1 224±1 142） MJ/m2, with （382±297） MJ/m2 for the university offices and （1 804±1 391） MJ/m2 for the commercial offices. Compared with the previous surveys and the code designs, the fire load density of the commercial offices was significantly higher, while that of the university offices was lower. In addition, the analysis of the combustible composition revealed a significant increase in the percentage of plastic. Based on this, this study recommends that consideration be given to differentiating between campus offices and commercial offices when designing for fire safety, and that attention be paid to trends in fuel composition.

Key words: fire load, digitized survey, office building, fire performance-based design