Block 168A Queensway is one of the first curved-shape blocks constructed by the Housing and Development Board (HDB). The sale of the 20-storey Curved Block was inaugurated by then Member-of-Parliament for Alexandra Constituency, Dr Wong Lin Ken, on 18 October 1973. The curved-shape façade earns the Block an interesting colloquial name from the residents, “the Butterfly Block,” for its striking resemblance to the holometabolous insect.



Before the Butterfly Block was constructed, early HDB residential blocks conformed to a uniformed slab design that was devoid of any aesthetics. The first two Five-Year Building Programmes focused on the elimination of squatters and the provision of low cost public housing. Hence, the first curved-shape block was designed with the intention to reduce uniformity in public housing and provide more aesthetically pleasing design features to cater to the different tastes and preferences. Instead of building a long and drab housing block, fanciful curvatures were added to the design of the Butterfly Block.



Following the success of the pilot project at Block 168A Queensway, the Housing and Development Board went on to build more curved shape blocks across the country. Curved shape blocks break the monotony of homogeneity in housing estates and they start the trend for more aesthetics to be incorporated in public housing.