Originally built in 1979, Yusof Ishak House is cherished by NUS students and alumni for its iconic design and sentimental value. The retrofit focuses on preserving and enhancing the building’s heritage while promoting conservation, sustainability, and decarbonization. By extensively preserving the existing structure, the project achieves an embodied carbon footprint less than one-third that of a comparable new building in Singapore.

All photovoltaic panels have been successfully installed, and the Temporary Occupancy Permit (TOP) inspection has been received. Final interior works including furniture, finishes and art installation is currently underway. The team continues to fine-tune systems for optimal energy use and thermal comfort by calibrating settings for the equatorial climate. Partial occupancy is anticipated soon after, with a formal opening ceremony anticipated in August 2025.

Site Progress and Implementation Learnings

Despite common pressures in Singapore’s construction context—particularly within university projects—for design elements to be “value engineered out”. The project team has retained nearly the full original design scope and avoided sacrificing design features, sustainability elements, or material quality to meet budget constraints. Several components have been fine-tuned during implementation to simplify systems, improve buildability, and enhance long-term performance.

Key implementation learnings include:

• It is possible to achieve system simplification without compromising design intent or energy performance targets
• Strategic reductions in embodied carbon can be achieved by optimising the use of structural hollow sections through perforation and material reduction
• Success demands the effective on-site coordination of passive design elements, such as the vault arches and natural ventilation strategies

Environmental, Social and Economic Impacts

Design enhancements include extending six vault arches externally to function as “climatic straws,” facilitating natural ventilation by drawing air into the building and through the central atrium, which will also benefit from natural lighting. Additionally, vertical fins are added to the exterior for sun protection.

It is too early to evaluate post-occupancy performance, as the building has not yet opened. However, data collection is planned following one year of use to assess the building’s impact in terms of operational energy, user satisfaction, and broader social and economic outcomes. Contractor and consultant teams are still in the process of finalising initial reporting for these areas.

Further Reading

“Retrofit case studies: an international survey” in Architecture AU, 2 May 2024.

Project Team: Campus Design Innovations Group at NUS