Recently, we have undertaken several design projects for the rooftop and would like to share my experience with readers. Rooftops belonging to owners are more common in houses or villas. Only owners of the top floor of a multi-storey building with sole use rights of the roof specified in the lease can modify the roof. However, the use of the roof is subject to the building deed of mutual covenant. It is not free to change or decorate the rooftop as you wish. Hong Kong’s building regulations are more stringent. Many buildings on the rooftops are illegal constructions such as roof houses, glass houses, tin houses, wooden canopies, etc. Even building a staircase at the top floor leads to their rooftops cannot be easily installed because of the structure involved or possible changes of the plot ratios. Before planning to renovate the rooftop, designers/builder advice should be sought as whether they need to apply for a permit at the Buildings Department. If permission is needed, owners should appoint an Authorized Person (a government-designated architect, engineer or surveyor) to submit building plans and co-ordinate construction works as required by the Buildings Department. With the approval and consent of the Department, the project will be carried out only by a registered general building contractor (these works cannot be carried out by registered minor works contractors).

According to the current regulations, if it does not damage the structure of the building, does not obstruct the fire escape of the building, does not damage the drainage system of the building, and will not affect the load-bearing capacity of the rooftop, one can be built on the rooftop without permission a prefabricated storage facility of a volume of 3 cubic meters or less, and a height of 2 meters or less. Most people will put a few tables and chairs and barbecue equipment on the roof, or some small flowers and pots, as long as the above principles are met, it is also possible.

In recent years, some local groups such as Rooftop Republic have advocated the use of rooftops to cultivate organic crops. This is an environmentally friendly and creative project worthy of promotion. Unfortunately, the law makes it difficult to realise. For example, if a large area is used for roof planting, it will still need to apply to the Buildings Department for approval, resulting in a very high renovation cost. .

When we design rooftops, we always consider the sun and the rain. Floors will generally be covered with easy-to-care light-colored floor tiles, stones or outdoor waterproof wooden floors. With the advancement of technology, outdoor building materials are much better than before. For example, Sunbrella in the United States specializes in producing outdoor furniture fabrics. Cast aluminum with a durable powder coated finish and custom hand woven all-weather, high density, PE (polyethylene) wicker is often used in outdoor furniture. We love to add some grass or plants around the rooftops, turning the rooftop into a cosy  family recreation place, or an ideal place for a barbecue buffet!