Hong Kong Housing Authority and Housing Department

The Housing Department has introduced aerial drone photography for inspecting the building quality of external walls of high-rise buildings in recent years.  Drones are smart and efficient devices that have revolutionised the conventional visual inspection approach used for years, and are conducive to reducing safety risks.

Before the introduction of this technology, external walls of high-rise buildings could only be inspected visually by poking heads out of windows from indoors. The viewing angle was narrow and the view was often blocked by interconnected pipes. Safety risks were also involved. These limitations undermined the judgement of the actual conditions of external walls and posed a major difficulty to acceptance inspection.

Drones carrying cameras take images while flying along external walls of buildings. With the aid of precise positioning technology, they are able to identify the location of the external wall of each residential flat, and capture clear and detailed images with high-resolution lens. With support of artificial intelligence (AI), drones are able to analyse the conditions of external walls by sequencing, categorising and examining the images, thus allowing us to identify anomalies such as defects or cracks on the surface of building structures, cracking or flaking of paint, and problems of condition of pipes and aluminum windows. The site supervisory staff review and validate the findings, and instruct contractors accurately to follow up and rectify the defects.