6 Star Green Star Office Design V3 Rating
Ever so often, you come across something that stands out as a landmark achievement in design and construction – In this case it’s both Australia’s, and the world’s, very first completely carbon neutral office building, Pixel.
The Pixel building designed by architects Studio 505, with the design team being led by Grocon; the services engineers were Umow Lai and the structure engineer was VDM Consulting- not only achieved a 6 Star Green Star Office Design V3 rating but also became the first completely carbon neutral building in Australia.
The development achieved a perfect Green Star score of 100 points with an additional 5 points for innovation – in context, 75 points is the minimum requirement for a 6 Star rating; thus making this the highest rating possible and the highest ever awarded by the Green Building Council of Australia, establishing a benchmark of world leadership. The innovative features which gained extra points included carbon neutrality, reduced car parking, a vacuum toilet system and an anaerobic digestion system.
Attaining such a high level of carbon neutrality for an office building is not easy but to help achieve this Pixel uses both wind turbines and photovoltaic panels installed on the roof to generate more power than it uses, with the surplus electricity fed back into the grid. As a result the carbon generated through the general operation of the building and the stemming from the materials used, and the construction phase is offset.
The construction phase of building is known to be one off the biggest contributors in generating carbon, therefore before the building exists, the design phase needs to take into account how this could be utilized and offset in order to create a building with carbon neutrality. Concrete is a prime contributor to this, with up to 70% of the embodied energy during construction stemming from this material; this was overcome through the use of a special blend of concrete that generated just 40% in carbon emissions.
Innovative features of the green roof and living edge wetlands along with wind turbines have been integrated into its design. Pixel’s roof plays a pivotal part in the building’s sustainability. With the building’s ecological value significantly increased by these two green initiatives that bring natural filtration and evapotranspirating to the building’s water cycle. These systems, coupled with the rainwater and grey water harvesting could mean that this building has the chance of becoming completely water self-sufficient.
The green roof was the result of a research partnership with The University of Melbourne, and involved a series of 300mm deep plantings on the roof, which provide initial filtration for the building’s rainwater harvesting. The living edges also add to Pixel’s green credentials by evapotranspirating the grey water harvested from the building. By incorporating a grey water harvesting system into the design, water which has not been contaminated, such as black water, can be re-used throughout the building amenities such as toilets and drinking taps, but also for the sites landscape irrigation.
The roof also has three locally developed and manufactured vertical-axis wind turbines, which are each capable of generating up to 60% of the power required by the average Melbourne household. Vertical axis wind turbines were chosen because conventional propeller turbines don’t handle the turbulence and winds found on top of buildings very well.
Providing the remainder of Pixel’s renewable energy is a system of both fixed and tracking solar photovoltaic arrays. With the tracking systems’ using sophisticated tracking devises to track the optimal point in the sky and increase the power output of the panels by up to 40%. All of the panels have been reclaimed from previous applications.
The exterior of the building has a façade incorporated into its design which provides sun shading during solar heat loading times, as well as protecting the interiors from glare and overheating; however this also draws lighting into the interior office space.
To manage utilizing natural sunlight whilst rejecting overheating, the building façade is floor to ceiling glass made from the clearest form of double glazed low-e glass available. Combined with the effectiveness of this glass is the shade panel exterior being very colourful, establishing this buildings pixelated personality. The lighting systems are programmed to work alongside levels of natural daylight, which switch off when they aren’t necessary; this enables automatic energy savings. The window design is also incorporated into this building management system, as they are programmed to open automatically on cooler nights as a means of letting the air flow through the offices, and keep the building cool; reducing the need to use traditional air conditioning systems.
The sustainable achievements of this building, after gaining 100% in the green star rating phase is an incredible benchmark for the commercial office industry to follow, but it is not a challenge that should be scoffed at. With Australian office buildings accounting for a very large percentage of the country’s total energy consumption and resultant greenhouse gas emissions, this really is a landmark step in the move towards a more sustainable future for commercial office buildings.