Study: Mission Sustainable, Part 1

This article is the first of two extracts from the UNStudio Sustainability Booklet. UNStudio’s Sustainability Platform compiled the publication to analyse sustainable approaches and techniques employed in a variety of UNStudio projects. In addition to introducing UNStudio’s sustainable mission, this article aims to provide knowledge and methods to facilitate sustainable building on a global scale.

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As the first unit of the series, this post examines the sustainable methods employed in the Singapore University of Technology and Design (SUTD), which was designed by UNStudio and Singapore-based DP Architects. The design approach for the SUTD is driven by the desire for an environmentally sustainable, economically viable campus that provides healthy spaces conducive to learning.

This study highlights three focus topics: green strategy, daylight strategy and facade treatment. For the green strategy, landscape design techniques for the SUTD engage indigenous greenery to reduce thermal gain and minimise the urban heat island effect on the campus. These plant species require minimal water and are woven into the building fabric via pockets of planters distributed along the corridors and integrated atop the sky gardens and green roofs. The daylight strategy for the SUTD aims to achieve a uniformly distributed and glare-free environment to increase productivity. For the facade treatment, rain screen design detailing provides sufficient shading along circulation routes as well as protective covering from rain.

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The rudimentary principles of passive building design have helped to shape the building geometry of the SUTD and to plan its spatial organisation. Building orientation, inter-block shading and corridor shading techniques all greatly reduce the building’s cooling load.

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A system of wind corridors works jointly to first, direct cooling, prevailing winds into courtyards and second, provide the ground floor with pedestrian paths that connect internal courtyards with campus-wide circulation patterns.

The daylight design strategy for the SUTD aims to achieve a uniformly distributed and glare-free environment to increase student and teacher productivity. Shallow floor plates provide opportunities to exploit the high levels of natural daylight, thereby reducing the need for artificial lighting. Horizontal shades are also designed to reflect and diffuse daylight carefully into the internal spaces.

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The SUTD buildings are oriented to minimise east/west solar exposure and to harness northeast and southeast prevailing winds for effective natural ventilation. These building-block arrangements also utilise inter-block shading and ventilation by means of 'voids' in the form of courtyards and other programmed corridor spaces. Tree-shaded walkways generate cooled, outdoor modes of circulation that render the campus walkable and low-carbon.

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Thermal comfort is achieved in air-conditioned spaces by means of the following integrated window design techniques. First, carefully selected glass types are installed to accommodate functional requirements for each area. Second, optimised window sizes and configurations are orientated to maximise daylighting while mitigating heat gain. Finally, appropriate shading devices are integrated.

Various dynamic modelling analyses of site, solar, ventilation and daylight conditions were carried out for the design of the SUTD, shaping the early planning and design parameters of the campus. These included campus orientation, distance and building massing. Examples include expansive courtyard systems, sky terraces and open collaboration spaces, allowing the building to 'breathe' and promote good cross-ventilation.

Solar analysis and daylight simulation tools were employed early in the design process for the SUTD to achieve a balance between ideal daylighting conditions and shading opportunities. Such devices have aided in minimising heat gain from the windows, designing effective shading devices and maximising glass performance.

Computer simulation tools such as computational fluid dynamics were used to optimise building geometries in order to produce a cooling wind corridor for ideal wind-flow through the outdoor gathering spaces.

The passive sustainable design approaches integrated in SUTD are infused with a range of comfortable outdoor and indoor spatial experiences, appropriate to Singapore’s tropical climate. Ultimately, the SUTD employs strategies that reduce energy use to 30% below that of typical institutional buildings.

UNStudio Team: Milena Stopic, Machteld Kors, Jennifer Zitner, Lei Yu, Sarah Roberts

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