On the empirics of housing illegality: A case study in Hong Kong

Yung YAU*, Daniel Chi Wing HO, Kwong Wing CHAU

*Corresponding author for this work

Research output: Book Chapters | Papers in Conference ProceedingsBook ChapterResearchpeer-review

2 Citations (Scopus)


Unauthorized building works (UBWs), particularly those attached to external wallsof buildings, have posed serious threats to the safety of the community in Hong Kong. Asestimated by the government, there exist around 0.75 million UBWs in some 39,000private buildings throughout the territory. In spite of the plenteous literature on this topic,associated empirical studies have been relatively rare, and this is not constructive for theexploration of the causes of UBW proliferation. To straddle the existing research gap,this study empirically explores what types of unauthorized appendages dominate andwhat factors affect the degree of proliferation of unauthorized appendages in multi-storeyresidential buildings in Hong Kong. Given that the majority of Hong Kong's populacelive in this type of housing, residents and the general public are prone to UBW hazards intheir environments. Therefore, an empirical study like this one is necessary for providingvaluable insights to public administrators for making more informed decisions. Throughappraising 429 multi-storey residential buildings in Yau Tsim Mong, the Eastern Districtand Kowloon City, a profile of unauthorized appendages in these buildings wereobtained. The analysis results indicated that over 98 percent of these appendages were notconstructed purportedly for increasing usable floor space, but for enhancing the amenitiesenjoyed by the residents. Besides, building age, development scale and managementcharacteristics have a strong bearing on the number of unauthorized appendages presentin a building. These findings have far-reaching implications on the formulation ofgovernment policies regarding building safety in Hong Kong.

Original languageEnglish
Title of host publicationBuilt Environment : Design, Management and Applications
Editors Paul S. GELLER
PublisherNova Science Publishers, Inc.
Number of pages22
ISBN (Print)9781608769155
Publication statusPublished - 2010
Externally publishedYes

Publication series

NameEnvironmental Science, Engineering and Technology
PublisherNova Science Publishers, Inc.

Bibliographical note

An earlier version of this manuscript was submitted to the Sixth China Urban Housing Conference held in Beijing, People's Republic of China in 2007. The authors would like to thank the delegates of the conference for their valuable comments. Besides, the authors gratefully acknowledge the financial support provided by the Research Grant Council of the Hong Kong Special Administrative Region (HKU 7107/04E and HKU 7131/05E), the Small Project Funding of The University of Hong Kong, and the HKU Research Group on Sustainable Cities Seed Grant, which made this research possible.


  • Building safety
  • Hong kong.
  • Housing illegality
  • Multi-storey residential buildings
  • Unauthorized building works


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