Passive design strategies including passive daylighting aim to enable the buildings to be energy efficient with no capital cost increment on active mechanical systems. The challenge of this project in India was to provide daylighting without unwanted solar (thermal) gain.Example project – Energy-efficient office complex The dominant design target of this new office building, winner of the Holcim Awards Bronze 2008 for Asia Pacific, on the outskirts of Hyderabad was the optimization of maximum shading and maximum use of daylight in order to reduce energy consumption. The proposed solution follows a twin strategy to achieve these conflicting goals.
Firstly, the general layout of the courtyard building optimizes orientation and provides maximum fenestration for work spaces in the north and south wings, whereas the east and west wings in which radiation levels are high are occupied by cores. Furthermore the building shape steps out upwardly on its south façades to create self-shading effects.
Secondly, the façade design is carefully analyzed to minimize solar heat gain while maintaining views and high daylight levels. Vertical shading fins on the façade run the full length of the building. The varying but fixed angle of the fins for each orientation is optimized through extensive shading coefficient analyses. To enhance the contributions to a sustainable performance of the building, rainwater is harvested to be used for irrigation and replenishing the aquifer and an onsite sewage treatment plant processes grey water for non-potable use.
The layout is organized around a series of interior courtyards which allow sun-light to penetrate down into the building’s core – a solution which is optimized to harness the sun’s energy, and decreases dependence on electric lighting. In this way, the design successfully meets two seemingly conflicting objectives – to maximize shading as well as the use of daylight.
read Holcim Awards project submission – “Energy-efficient office complex”, Hyderabad, India