Arup

Arup in Australasia is part of the global Arup Group, a multidisciplinary firm of designers, engineers, planners, project managers and consultants. Operating in 37 countries there are three main business areas - buildings, infrastructure and consulting. Arup came to Australia in 1963 to undertake the structural design of the Sydney Opera House. Today Arup in Australasia has almost 900 staff in eight offices. We shape a better world.

For more information on ARUP, See http://www.arup.com.

Shaping a better world - from buildings to cities

By Haico Schepers, Senior Associate, Arup

When I started working in the building industry 10 years ago, I had a passion for sustainable design. The Brundtland Report had just been released and it defined sustainability as: "Development that meets the needs of the present without compromising the ability of future generations to meet their own needs."

At that time, green buildings were all about being climate responsive. Design focused on making them energy efficient, using natural systems such as daylight and natural ventilation. Mechanical and lighting systems accounted for 75 per cent of a building's energy use, but the industry was not yet focusing their attention on water and material issues.

A decade on we have a far more sophisticated approach to sustainability. There is a plethora of rating and benchmarking tools that have encouraged market change. We are more focused on improved energy efficiency and water efficiency, albeit often limited to legislated or tenant-prescribed minimums. We like to 'talk the talk' and sometimes we even try to walk it, yet the overall energy consumption of Australian building stock has increased 20 per cent since the Kyoto Protocol was put in place.

It is now becoming more and more obvious that climate change is a significant issue affecting future generations and our economic stability. The Stern Review is one of the most recent documents reporting on the impacts of not adopting a more sustainable living approach. It considers the economic impacts caused by climate change. Sir Nicholas Stern suggests a 60 per cent reduction in CO2 emissions is a responsible target to limit the impact of climate, not avoid it. This is a significant issue for Australia as we are the twelfth biggest CO2 emitter in the world, and the largest per capita.

The impacts of climate change can be wide and varied as the earth tries to establish a new balance. They can include flooding, drought, heat waves, increased high winds and other climatic events. In Beating the heat: keeping UK buildings cool in a warming climate, Sir Richard Rogers highlights that buildings are responsible for 50 per cent of the world's generation of CO2.

Studies by the CSIRO indicate that evaporation and reduced rainfall will be significant issues for Australia. These will have a major impact on our economy, and eventually it will be imperative for Australia to sign up to international CO2 conventions. A one-size-fits-all approach will prove inadequate, as warming will improve conditions in some areas but force significant changes in others.

Future buildings will not only need to be less carbon intensive, they may also need to respond to greater local environmental challenges. So what can the building industry do about this? In this new paradigm is a six-star building enough? The two fundamental issues to keep in mind are that existing buildings will continue to demand energy similar to existing rates and that it is difficult to significantly reduce this demand by more than 20 per cent. Any new building must therefore set significantly larger benchmarks as they only add to the total energy demand.

To achieve the carbon efficient economy suggested by Stern, Australian buildings would need to reduce their energy consumption by 75 per cent of what is currently prescribed by the Building Code of Australia. A commercial building, for example, would require a radical change in design to achieve a 75 per cent reduction of energy as mechanical systems alone will not achieve these reductions. Floorplates should be designed to use all natural light instead of artificial sources and should be capable of passive ventilation. The result is narrower building designs and, some argue, lower-rise construction that tries to maximise flexible mixed-use potential.

Facade design plays a crucial role in that it can, and should, interact with the surrounding environment to allow fresh unconditioned air into the building when possible, maximise useful daylight and minimise heat gains and losses. Facades will start to become energy sources using biomass or integrated photovoltaics to augment the energy balance.

The facade is the foundation to how services in a building are designed and integrated. In the future, the embodied energy of production will also be a significant issue in building design. The concept of doing more with less will be fundamental. Computer use and the ability to perform design optimisation is a key resource in the development of new efficient lightweight structures, which require less steel and concrete.

The National Aquatics Centre, designed for the 2008 Olympics in Beijing, demonstrates how technology improvements can affect design in terms of material use and software technology employed. Its facade will help the building meet both architectural and environmental requirements by minimising the steel structure; maximising the daylight through the transparent facade; and using 20 per cent of the solar energy trapped within the building to heat its five pools and the interior area - the equivalent of covering the roof with photovoltaic cells. Its 100,000m2 of lightweight ETFE bubble cladding, a tough recyclable material, turns the building into an insulated greenhouse.

The Squadron Headquarters, RAAF Richmond, was designed with an operable facade and mechanical system capable of reducing energy consumption by 75 per cent compared with a normal building. Automated external blinds ensure unwanted solar radiation does not penetrate the building envelope during certain times of the day. The roof and vertical facades are designed to maximise reduction of direct solar gain while optimising daylight, reducing energy use for lighting. The facade is also designed to allow airflow into the building as a means of naturally ventilating circulation and breakout areas and allowing the office spaces to function in mixed mode operation. This reduces the need for artificial cooling and decreases energy consumption.

As mentioned previously, new buildings need to significantly reduce their energy requirements, especially given that 10 per cent of the entire energy use of a building is locked in embodied energy. New buildings should aim for a 90 per cent reduction in energy use compared with buildings today, in other words we need to design zero energy buildings.

Arup has already developed zero carbon developments such as
Beddington Zero Energy Development (BedZED) in the United Kingdom, Treasure Island in San Francisco, and recently Dongtan Eco-City in Shanghai. The principles developed at Dongtan include:

• all energy provided by distributed power from a variety of sources - photovoltaics, wind, biomass and consideration of nuclear sources
• a focus on multi-modal public transport and direct and convenient cycle and pedestrian routes as opposed to ring road distribution
• use of water recycling and natural treatment systems
• large accessible green spaces and town squares
• social and economic inclusion and viability.

These designs show that a 90 per cent reduction is possible and is economically feasible when holistic thinking and future cost is assessed. I believe that this level of design and integrated planning will become a cornerstone of future developments, with ever-stricter controls on energy and carbon footprints limiting the size of energy intensive developments. Buildings built today that ignore these principles risk becoming obsolete in the not too-distant future.