Note: The following information is lifted from BCA, and is re-produced here for reference only. As this page may not be updated as frequently, you are highly encouraged to check with the authorities for the latest updates and information.
Any advertisement, electronic billboard, or signboard fixed in a verandah-way or over footpath shall not be less than 2.5 metres above the level of the verandah-way or footpath.
Where a roadside drain is covered, no advertisement, electronic billboard or signboard projecting over any street shall be erected less than 2.5 metres above the cover of the drain, measured vertically from the top of the cover to the underside of the advertisement, electronic billboard or signboard.
No advertisement, electronic billboard, signboard or skysign shall project over any street by more than 60 centimetres beyond the building line with a minimum height of 3.75 metres but less than 5 metres measured vertically from the roadway.
No advertisement, electronic billboard, signboard or skysign which is displayed more than 5 metres above any street shall project over the street beyond the building line by more than 1.5 metres except on balconies or canopies.
(Source: BCA)