Energy Efficient low-carbon retrofit of two 40 year old existing educational buildings at the National University of Singapore. In terms of energy efficiency, both buildings should be retrofitted to achieve an energy use intensity (EUI) of 100 kWh/m2/year or lower. For SDE1, the first building to complete, a measured EUI of 45 kWh/m2/year has already been achieved.

Design challenges included the fact that the long facade of the biggest of the buildings, SDE3, was facing East and West, hence, exposed to both the low morning and the low evening sun.

An effort was undertaken to see if the existing heavy facade shading could be re-used for a lighter more elegant modern facade screen. Regretfully, it did not make financial sense.

A comprehensive design brief focusing on environmental performance targets was prepared by the client. This included hybrid ventilation, where "light air-conditioning" of 26-28 degrees Celsius is combined with creating a pleasant breeze using energy efficient and silent ceiling fans.

The buildings were officially launched on 2 February 2023 by Deputy Prime Minister, Heng Swee Keat.