May 4, 2009 Australian developer Grocon plans to build the country’s first carbon neutral office building on a former brewery site in the city of Melbourne – and possibly the first of its kind in the world. According to the developer, the $6 million, four-storey building has been designed to generate more energy on the site than it uses, offsetting the carbon emissions produced to operate it – and, in time, the greenhouse gases generated in making and installing the construction materials.

By aiming to be carbon neutral – which is a step further than carbon zero – Grocon is hoping to achieve a 6 Star Green rating. “Any carbon emissions used in the building’s ongoing operation will be offset by renewable energy from large photovoltaic (solar) panels on the roof as well as wind turbines,” says Daniel Grollo, Grocon’s CEO.

“Some research has been done on carbon neutral buildings overseas, and there are several small buildings, different from the Pixel building in Germany and the United States, but we believe this will be the first of its type in an urban environment.”

Architects Studio 505 has designed the building, with sustainability experts Umow Lai providing environment and engineering advice.

The proposed building will feature several other key green initiatives, which will contribute to the building becoming carbon negative.

An absorption heat pump chiller, imported from Europe, will be used to heat and cool the building. The chiller uses ammonia as a cooling agent, which has no ozone, global warming or Legionella emissions.

More than 75 percent of the building’s rooftop, in addition to accommodating the solar panels, will be covered by native grasses, which will filter the rainwater and insulate the building. Rainwater will provide most of the building’s water supply; and gray water will be recycled, in an Australian first, through a reed bed system that also shades the windows.

Fresh air will be circulated through a raised floor at three times the rate required by the building code in much the same way as air vents on a car dashboard, with an individual control at each workstation.

Exposed concrete ceiling slabs, cooled by pipes embedded in the concrete and transporting water, will offer radiant cooling with minimal energy use.

Metering will be stationed on every floor to provide detailed monitoring of energy and water consumption, which can be fine-tuned if irregularities show up.

Construction materials will be selected for low-embodied energy, avoiding volatile organic compounds and other gaseous chemicals.

The Pixel building is due to be completed by March next year. Grocon’s plan for a carbon neutral development runs ahead of most deadlines set by countries. In the United Kingdom, the government has stated that by 2019 all residential projects will be carbon neutral and non-residential buildings carbon zero. In the US, the government position is less clear but is expected to adopt a similar stance to the UK.

While California is clearer with “all new construction to be zero net energy by 2030”, Australian requirements for commercial property are yet to be finalized.

Whereas the Pixel building is using its own urban site to achieve carbon neutrality, other innovative carbon zero projects in the US, UK and Germany are achieving their low-carbon targets through off-site provisions, Grocon argues.

"The solutions in Germany use very large photovoltaic arrays which cover more than the site of the building, and at least one of the solutions in America offsets its carbon through carbon sequestration in an adjacent forest," Grocon's launch document states. "Grocon’s Pixel delivers carbon neutrality on a building utilizing reasonably traditional commercial building materials."

Paul Best