GHD used the IES Virtual Environment (IESVE) to optimise performance and energy efficiency of an extension to Yarra Valley Water Headquarters in Victoria, Melbourne, to achieve a 5* Green Star rating.
The 2000m2, three-storey scheme includes a sealed, high-performance building envelope, which is designed to reduce heat gain to the building while enabling good daylight distribution to reduce the need for artificial light. The pioneering, integrated development also includes TermoDeck, hollowcore floor slabs, through which conditioned air is passed, before being ducted to an underfloor displacement ventilation system.
Modelling the scheme using IES’s VE-Pro tools enabled the team to develop a cost effective, energy efficient solution. The building’s design energy consumption is 80.8 kwh/m2/year; carbon emissions are 58kg of CO2/m2/year which is almost 61% less than Australian best practice. “Through integrated working, the GHD’s architecture and engineering teams developed the building’s design to achieve neat, energy efficient and cost effective solution,” says Hollingsbee.
The integrated solution meant that the design had to be developed to achieve the optimum solution. Options explored included, the size of the building’s windows and cooling loads to get the balance right between allowing daylight into the building and eliminating solar gains, and the option of combining the hollowcore system with natural ventilation. The analysis led to the use of a thermally broken double glazing system with low emittance coatings to cut down on the cooling loads for occupant comfort and a mixed mode solution to provide flexibility to the occupants to allow them to naturally ventilate the building in the future.