If I recall my previous projects correctly, the formal process of constructing a roof terrace is as follows. 1. MCST Approval Approval must be sought from MCST to construct as the roof top terrace may impact the external facade or building outlook. 2. URA (http://www.ura.gov.sg/homeowner/stratatitled-buyproperty.htm#4) As the strata title locks in the GFA of your unit, any roof terrace should not incur an increase in GFA. There are several ways of avoiding the increase in GFA. a. install a open to sky roof trellis with a retractable awning over it. b. Construct a roof terrace butting against a wall to a maximum of 2m overhang. c. Construct a 4mx4m covered pavillion on the basis that 2m overhang from edge of roof to wall for roof terraces are exempt from GFA. Therefore a 4mx4m covered pavillion is similar. d. cbuy an umbrella. Of course, items (a), (b) or © will require URA submission by the Architect and is subject to approval from the Planner on a case by case basis. Alternative if the Condo development has GFA to spare, (highly unlikely), you can apply to purchase it from MCST and revise your strata title. 3. BCA A roof terrace is defined by BCA as "Building works carried out for or in connection with any single storey trellis, pergola, shelter, gazebo and the like." Thus no submission is required. Hope this helps you out.