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 41 kWh/m2/year has already been achieved (2022). For SDE3, a measured EUI of 43 kWh/m2/year was achieved in 2023. Both EUI figures exclude any contributions from renewable energy.

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, so the new facade screen was made from new materials.

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.

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Acknowledgements:
This ambitious retrofit project was the brainchild of Nirmal Kishnani (NUS), Heng Chye Kiang (NUS), Wong Yunn Chii (NUS), Erik L’Heureux (PhD) FAIA (NUS) and Wolfgang Kessling (Transsolar KlimaEngineering), who set the stage and design direction for the project. During the project design and implementation stages, we had a great collaboration with architect Erik L’Heureux (PhD) FAIA (NUS) and his team with CPG Consultants on all architectural matters, especially the beautiful and functional facade design, and with WSP for MEP matters. Great credit goes to Lam Khee Poh (NUS) and Giovanni Cossu (NUS) who both worked tirelessly to deliver the project to completion, and the number of other professional, who enabled the success of the retrofit project. Lastly, the highly skilled and dedicated energy manager, Bertrand Lasternas (NUS), did an excellent job energy-optimising the building during operation while working to integrate performance with the design direction. Go to this link for a more exhaustive list of project: https://cde.nus.edu.sg/news-detail/sde1-and-sde3-win-prestigious-design-awards/