Andrew Kung Sui-lun is the immediate past chairman, building surveying division, of the Hong Kong Institute of Surveyors (HKIS). He warns of the dangers that property owners face if they build or leave an unauthorised structure. What are the dangers posed by unauthorised structures, such as those erected on rooftops, balconies or external walls? Unauthorised building works include shelters or dwellings built on rooftops or enclosed balconies and carried out without the prior approval and consent of the Building Authority. It is very likely that such unauthorised work would not have been carried out by building professionals, and is therefore not likely to be structurally safe or fireproof. For example, the weight of a rooftop house, together with the occupants and their fittings and furniture, may exceed the floor load permitted by the building code. What is also a danger is that if someone cooks and uses electricity inside an illegal rooftop house, they could cause a fire which might spread to the surrounding structures – especially if the materials used in the illegal structure are not fire-resistant. And in extreme weather conditions, such as typhoons, an illegal structure could be blown off the building. Landlords who knowingly build or leave unauthorised work on their rooftop are taking serious risks which could endanger people’s lives. Due to his acts of negligence, the landlord would have to assume all legal responsibilities, including paying compensation to the victims injured or for any death(s) caused. Insurance companies do not cover liabilities arising from illegal building works. What are the legal consequences if the landlord ignores orders issued by the Buildings Department to remove an illegal structure? If the illegal structure is not considered an immediate danger, the Buildings Department would usually issue a statutory order first to request the landlord to have the work removed within a given period of time. It may also issue an order against the title to the property as a way to restrict the marketability of the property. If for any reason the landlord fails to carry out the required work on time, then he is deemed to have committed an offence and is liable on conviction to a maximum fine of HK$400,000 and imprisonment for up to two years. There is also a fine of HK$20,000 for each day during which it is proved to the satisfaction of the court that the offence has continued. The Building Authority may send a government contractor to carry out the removal of the work and recover the cost from the owner, plus a supervision surcharge. Can owners pay extra rates or a ‘premium’ to keep an illegal structure? For minor unauthorised building works, such as drying racks, canopies or supporting frames for air conditioners, the owner may join the Household Minor Works Validation Scheme arranged by the Buildings Department in order to keep them. Other than that, all unauthorised building works, such as illegal rooftop dwellings, have to be removed in due course. Owners are advised to consult an authorised person before commencement of the removal works and to make a formal application for approval and consent from the Buildings Department if necessary. By the same token, owners who want to carry out the alterations and additions are advised to consult an authorised person for advice and to make a formal application for approval and consent from the Building Authority. Some owners may argue that they are willing to pay for the extra gross floor area gained from an unauthorised structure such as a rooftop dwelling or enclosed balcony, so long as the structure has been proved by an authorised person to be structurally safe, and to represent no fire hazard. Unless the building on which the previously unauthorised structure is built has not used up the permitted gross floor area – which is extremely rare – the owner is always required to demolish an unauthorised work without delay.