CASE STUDY – 5 November 2009 – How to deal with an existing and ageing national building stock designed and built in times when requirements for high standards of energy efficiency were not even contemplated? This a dilemma facing the architects of energy efficiency programs here in Australia and elsewhere in the world.

The issue of efficiency standards in new buildings and those undergoing major refurbishments is relatively easily dealt with through the Building Codes of Australia. It places all participants on the same footing, whereas owners and occupiers of existing buildings just trying to improve their energy performance will be inequitably placed, depending on the current state of their premises.

The National Strategy on Energy Efficiency, published by the Council of Australian Governments in July prefers that the marketplace drive the generation of incentives to improve efficiency. The Strategy introduces plans for the mandatory disclosure of a building’s energy performance and making much more information available to those parties buying or leasing properties.

The inference to building owners is clear – invest in energy efficiency or lose market advantage.

Valad Property Group

Despite the challenges in driving new standards of energy efficiency in existing buildings, the Valad Property Group showed the benefits of pursuing an energy efficiency program. Savings of $69,000 per year are forecast at its Elizabeth Street, Sydney, building following the completion of energy efficiency upgrade work currently underway.

The biggest saving at the 13,460 square metre building will result from chiller and building management system upgrades. Replacing diesel burners in the boilers with gas burners, and upgrading the podium glazing will deliver additional benefits.

The building’s NABERS energy rating is expected to improve from 2.5 to 4 stars, with a 37 per cent reduction in building-related greenhouse gas emissions.

The building upgrade was partly funded by a $500 000 grant awarded under the AusIndustry’s Green Building Fund program.

Energy efficiency measures

There are general measures that Energetics’ recommends for energy efficiency programs in existing commercial buildings.

Owner-occupiers responsible for building management should start by reducing baseload energy usage. As plant and equipment on average use 40 per cent to 60 per cent of total energy in a commercial building, they should be switched on only during operating hours.

Secondly, plant and equipment should operate at maximum efficiency.

Once baseload energy is minimised, the next step is to automate some controls.

Significant savings can be made by introducing occupancy sensors to control lighting and air conditioning in rooms that are intermittently occupied, such as conference rooms, toilets and kitchens.

Excess lighting should be removed, particularly in non-critical parts of an office by simply taking out the tubes.

Laptops should be introduced wherever possible because their inbuilt power management systems make them far more efficient than desktop computers.

Further, companies should consider the impact of laptop, mobile and blackberry chargers that are left plugged in after the devices are charged and removed. If the chargers are left on, “that little transformer” is drawing power even if the device it was charging is off or removed. If you have three or four of them on your desk powering things, that can add up for a large organisation.

The biggest mistake an organisation can make, however, is complacency.

Once energy efficiency gains have been achieved, organisations will often become complacent and bad habits return. Generally lights are left on and plant efficiency starts to decline.

Establish a network of staff members with a particular interest in the environment to act as “energy champions” to ensure there is no single point of failure. These staff members can carry out regular checks to ensure sensors are working, temperature is at a sensible level and plant and equipment switches on and off at the correct times.

For some building operators it’s relatively straightforward to implement a number of these measures and start to benefit from energy savings and reduced emissions. However from there on in it gets rather more difficult. In order to unearth the next layer of efficiencies and savings it’s necessary to really consider the way a building’s mechanical and electrical systems operate – and this is where a consultant can really bring value to our clients.

Nick Jones is principal consultant, buildings and infrastructure, Energetics

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