Aurecon Engineers used the IES Virtual Environment (IESVE) to optimise energy use, solar gain and occupant comfort, whilst reducing running costs of this 100% glazed façade building.
151 Cambridge Terrace is one of the most desirable commercial locations in Christchurch, New Zealand. Not only is it one of the safest, most earthquake resilient buildings in the country, the six storey office building is highly efficient in terms of energy and cost, despite having a fully glazed façade.
To achieve high levels of efficiency, Aurecon Engineers used the IES Virtual Environment to carry out extensive Energy, Solar and HVAC modelling to explore and implement the most energy and cost efficient design measures, as well as ensuring occupant comfort. Significant modelling was carried out on the efficiency of the façade and its effect on the internal cooling loads of the building.
The IESVE was used to optimise fins extending from the building to provide a good level of shading while still allowing views when seated and standing. The fins were fitted mainly for solar gain, reducing the overall cooling requirements for the building by around 15-20% when compared to the same façade with no external fins. Each fin has a graduating pattern that reduces the amount of solar gain through the fin. The pattern transitions from opaque at the top and bottom of the fin to clear in the middle.
The rate of transition was modelled using the IESVE, optimising occupant comfort, solar gain and building energy use. Low-E Insulating Glass Units were chosen for their neutral blue appearance and high-visual light transmission, preventing heat loss and providing a visual connection between the interior and surrounding cityscape.
Using IES’ ApacheHVAC module, Aurecon were also able to ensure the mechanical systems were designed for energy efficiency, with heat exchange on the fresh air and on the air conditioning system. LED lights were also chosen for their energy and cost efficiency.
The building is the first in New Zealand to incorporate Triple Pendulum™ base isolation bearings into its design, making it one of the most earthquake resilient buildings in the country. It also won a Merit Commercial Office Property award at the New Zealand Property Council / Rider Levett Bucknall Awards 2015.
“We are very proud of the outcome on 151 Cambridge Terrace. The anchor tenants Deloitte have been very impressed with the internal comfort and the performance of the external shading is a key part of this. The thermal modelling we completed allowed the architect to achieve the desired aesthetic whilst mitigating energy use as far as possible.”
Peter Rickard-Green, Technical Director, Aurecon