This institutional building aims to be an exemplary Singapore facility for the conservation of energy by creating effective demand reductions through passive strategies avoiding heat gains while maximizing day lighting and natural air movement. The building design takes advantage of the North South orientation and the views and connections between the buildings. Early studies on the impact of thermal gain and accessibility to daylight were major factors in considering optimal programmatic arrangements and the design of an environmentally efficient façade.
The Singapore University Of Technology And Design (SUTD) building orientations are configured to minimize East/West solar exposure and to harness Northeast and Southeast prevailing winds for effective natural ventilation. Building blocks were also planned with considerations of inter-block shading and ventilation using ‘voids’ in courtyards and other activity corridor spaces. Thermal “mapping”, through solar analysis and dynamic solar exposure indicating diurnal heat flux shows the effectiveness in the spatial configuration of building massing and voids.
Natural Ventilation Analysis
The well shaded and well lit courtyards are connected to campus wide circulation spaces through “wind corridors” that direct prevailing winds into courtyards while providing pedestrian paths cutting through the ground floors. Numerical analysis was carried out using CFD to investigate the airflow patterns around the exterior building envelope and inside the courtyards. The airflow analysis shows the pedestrian paths are effective in bringing air movement to the courtyard spaces.
Daylight Penetration Study
The target of day lighting design for SUTD is to achieve a uniformly distributed and glare free visual environment. The shallow floor plate brings good opportunities to use natural daylight and reduce the need for artificial lighting, but it also requires the striking of a subtle balance between daylight and solar heat gain. Glass selection, window sizing, positioning and shading design are key measures to bring about this balance. It is expected that glass with light to solar ratio of 1.5 and above needs to be used for the optimal solution. The horizontal shades or light shelves are designed to reflect and diffuse daylight entering internal spaces.
For an efficient facade design the strategies adopted were:
- Unitised curtain wall with Window Wall Ratio of 60%.
- Vision Glazing is provided with high performance Low Emissivity coating. The vision panels are designed as casement windows. This provides flexibility for the occupant when natural ventilation is required. In strategic locations along the corridors, some openings are provided to allow cross ventilation. In locations where classrooms are facing major traffic, laminated glass is proposed.
- Floor Shade – Planter boxes are incorporated to this element. This is effective in providing shading and at the same time provides greenery for the occupants to enjoy. Aluminium cladding is used for the planter box for ease of maintenance.
- Horizontal Sunshades act as shading elements and glare control while indirectly acting as light shelves to divert diffused daylight further into the building floor plate.
- Strip windows are provided along the facade, which provides more uniform daylight and due to lack of break between windows prevents contrasts of light and dark areas.
Wind Driven Rain Analysis
The Wind Driven Rain Analysis provides insight in the buildings interaction with the rain during wind directions that are the most critical. An appropriate wind gust velocity is determined and the resulting vulnerable areas under various seasons are identified.
The rain penetration depends on the wind gust speed, wind direction and the rain droplet size. A wind driven rain analysis helps study the transient naturally ventilated spaces, which might allow some rain penetration.