Zero - A Building of the Future Now

Written by Network member: Jon McNaught, GHD

Is it possible for a commercial building to run solely on energy generated on-site, using only renewable sources?

In 2007 GHD developed the concept building ‘ZERO,’ located at Richmond Station in Melbourne. Zero was developed as an example solution to our current environmental demands, demonstrating what can be achieved in building energy and resource efficiency. It also showcases building practices that are humane, sustainable, efficient and beautiful.

GHD’s design of ZERO was assessed using the Green Star environmental rating system, a framework developed by the Green Building Council of Australia that evaluates the environmental design and achievements of buildings. The approach to the design centered on benchmarking global best-practice building designs that would then be developed to enhance energy performance beyond current benchmarks.

The overarching goal of the building was zero operating CO₂ emissions, whilst maintaining the standards of a typical office building and occupancy comfort.

The following is a snapshot of the features that GHD employed when designing ZERO to achieve zero net external power consumption.

Green Building features

Indoor environmental air quality

ZERO features a mixed mode ventilation system, using both mechanical and natural ventilation. The mechanical component achieved a 200 percent improvement on outside air quality over standard designs - well above that required by Australian Standards - and is designed to control humidity in occupied spaces. The natural ventilation system relies on cross ventilation and stack ventilation using thermal chimneys.

Reduction in peak energy use

Coupled with renewable energy sources (solar and wind) ZERO minimises greenhouse gas emissions by using energy efficient systems that reduce peak energy demand.
The solar concentrator CHAPS (combined heat and solar power) system generates electricity and hot water for the absorption chiller and domestic hot water.

Encouraging sustainable travel

To encourage sustainable modes of transportation – public transport, walking and cycling- ZERO’s design contains no car parking spaces.

Heating, Ventilating, and Air Conditioning (HVAC) Services

ZERO adopts a number of innovative design technologies to achieve the electrical consumption target of 70kWh/m2 annum. Depending on external conditions, ZERO can operate in natural ventilation mode without using mechanical energy from active cooling systems.

Several active and passive techniques were employed to control internal temperature, including:

Broadened thermal comfort band

Conventional office buildings are typically designed to maintain space temperature of 21-24°C. ZERO was designed to have a comfort band of 20-26°C. The design incorporates windows that open, giving occupants a greater acceptance of the wider temperature bands, and connection to outside conditions.

Phase change materials

ZERO incorporates interior wall panels with integrated phase change materials to provide additional thermal mass to its lightweight internal walls. These panels reduce energy consumption and increase thermal comfort by reducing the temperature peak.

Chilled beams

Displacement ventilation is supplemented with chilled beams at ceiling level keeping the area cool without the use of fan energy.

Solar absorption chiller

At times when peak cooling is required, solar energy is at a maximum. ZERO was designed to generate solar hot water as the heat source for an absorption chiller that provides chilled water for air handling systems and chilled beams.

Double façade

ZERO’s double façade design improves the thermal performance of the building, keeping it cooler in summer and warmer in winter.

Heat recovery

ZERO’S heat recovery system consisted of air-to-air heat exchangers that use exhaust air heat to preheat the supply air to the building.

Solar energy feature

A key electrical component involved the use of conventional photovoltaic (PVs) panels on the buildings façade and the upper portion of the roof of the nearby train station, drawing zero energy from the grid over an annual cycle.

Costs

Whilst there is a slightly higher initial investment in construction of a building of this type, the building does payback within the design life of a typical commercial building. Initial cost studies, including energy generation data and costs, project payback periods without carbon taxes of around 25-30 years.

Conclusion

GHD’s development of ZERO confirms that a commercial building running solely on renewable energy sources can be built with the appropriate investment being provided.