Garigal, Belrose, NSW

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This 3-storey commercial office building have been planned with environmental sensitivity in mind including the use of greywater, energy efficiency, a combination of natural ventilation and individually controlled air-conditioning systems.

Summary

Garigal is a strata office building comprised of 83 office suites on three levels plus a basement car park located in the Austlink Business Park in Belrose in the northern beaches area of Sydney adjacent to the Garigal National Park. The primary design criteria was minimising the building's ecological footprint within the constraints of commercial viability.

The Garigal design team had to address the challenges of applying sustainability principles to a strata building in which individual owners control most of the interior design and usage decisions within their strata space. In a single-owner building housing large corporate tenants, the owner has total control of the services affecting consumption of energy and water, and indoor environmental quality.

Two conventional strata office buildings of similar size that were developed earlier by Glenside Group provided benchmarks for testing the effects of sustainable design concepts. This ensured the ESD budget for Garigal was used cost-effectively.

When Garigal is fully occupied its ESD features will:

• Reduce base building power consumption by 50% to 60% compared to similar projects.
• Reduce greenhouse gas emissions by up to 770 tonnes per annum for the building - equivalent to taking more than 200 cars off the road.
• Reduce mains water consumption by est. 1,300,000 litres pa.
• Eliminate sewage discharge to ocean outfalls. All sewage is treated and recycled.
• Provide fresh air via cross-flow ventilation to improve indoor air quality and provide a healthy work environment in which workers will be more productive.
  

The project team
Owner: Glenside Group Pty Limited
Developer: Lot 111 Pty Limited
Financier: L M Investment Management Pty Ltd
Project manager: Belbore Project Management
Architect: Turner + Associates
Interior designer/architect: Design International
Engineering Consultants: Cundall Johnston & Partners Pty Ltd
Structural Engineer: VDM Group
Services: ITC-Services
ESD consultant: Michael Mobbs
Cost consultant: BMT (Quantity Surveyor)
Builder: St Hilliers
Leasing agent: CBRE
Facility manager: CBRE
Landscape design: PSB

Checklist of sustainable features

Energy
Indoor Environmental Quality
Productivity
Water
Waste Water

Motivations and lessons

The owner's view - an interview with David Hawes, Managing Director of Glenside Group, the owner of Garigal

April 2008

What are the main reasons why your company chose to develop a sustainable strata office building?

Back in 2003, when the Garigal project commenced, Glenside Group believed that in the future there would be a constantly increasing demand for buildings that are designed and operated on sustainability principles. Further, Glenside believed many of the sustainable features included in Garigal as 'extras' may become compulsory requirements in new buildings. Importantly, developing Garigal was consistent with our personal views on ecological sustainability.

We saw there was an opportunity to develop buildings now that would meet the demands of businesses seeking to take a lead position in demonstrating their corporate social responsibility re ecological sustainability. This is an emerging market. And importantly, Garigal could already meet future building ESD requirements.

In particular, we saw an opportunity for Glenside Group to build a strong capability in sustainability projects and to gain recognition for our achievements, i.e. for Glenside Group to become recognised as an authority in the development of sustainable strata buildings.

What are the best things that have come out of doing a sustainable building?

Glenside Group has a commitment to develop environmentally sustainable buildings to reduce energy and water consumption, reduce greenhouse gas releases and reduce building operating costs; and to provide healthier home and work environments. A very important part of the design process was engaging Michael Mobbs to work with the design team as Sustainability Coach.

In believe the three best things to come out of Garigal are:

1. Reduction of greenhouse gases
Reducing electricity consumption by 50% to 60% compared to a similar standard building. This is a saving of more than $500pa for each office suite owner, and importantly, will reduce greenhouse gas emissions by up to 770 tonnes per annum for the whole building. This is equivalent to taking more than 200 cars off the road. Further reductions will be achieved if all occupants 'take' the initiative shown by our initial occupants in minimising their use of artificial cooling.

2. Reduction of mains water consumption
In recent years we have come to learn that water is a scarce resource. In office buildings, typically 70% of mains water consumed is used for flushing toilets. This is a waste of high quality drinking water. In Garigal all black water is collected and treated on site and the recycled water is used for toilet flushing and garden watering. Rainwater is collected and used for the same purposes. As a result about 1.3 million litres per year of potable drinking water can be saved and the volume of sewage to be treated by the Sydney sewage system will be reduced.

3. Increased worker productivity.
A limited survey of occupants who moved to Garigal from other office buildings indicates the most significant changes have been a large reduction in the use of air conditioning and having windows open most of the time to access fresh air.
Business owners have noticed an improvement in office ambience. Their staff has more positive attitudes, there is less absenteeism, there is more communication within the office and staff is more productive. Most respondents believed they were getting much better value at Garigal than they had had in their previous offices.

What are the things that you did that made the project work well?

The location and shape of the site demanded that Garigal be designed with a north-south longitudinal axis with a central corridor to make optimum use of the site in terms of office accommodation. The north-south orientation meant that offices on the east side of the building would be exposed to the heat of the morning sun and those on the west would be exposed to the afternoon sun. This is the most difficult aspect to design to. The traditional approach would be to install high performance glass and energy efficient air conditioning.

The Garigal design team was challenged to devise sustainable design elements that would reduce the heat load on individual office suites and provide natural ventilation to reduce the need for air conditioning, and hence reduce electricity consumption and greenhouse gas emissions. A major challenge was to achieve cross-flow ventilation in a building with a central internal corridor and with most units having only one external wall.

1. Solar Operated Blinds and Overhanging Balconies
To reduce the heat load, the perimeter facade of the building was designed with large over-hanging balconies fitted with an automated retractable blind system controlled by solar sensors. The blinds are located on the outer edge of the balconies instead of immediately in front of the windows. This creates a cool breezeway space between the blinds and the window glazing as well as shading the glass from the sun's radiant heat.

The blinds help to keep the air temperature down in summer, reduce the need for air conditioning and maximise the number of days windows can be opened. The blinds are made of a see-through fabric which shades the glass and reduces glare, but still allows occupants to enjoy the view. The blinds are retracted automatically to prevent them from being damaged when there are strong winds.

2. Natural Ventilation
The solution was to make each internal corridor a breezeway and put adjustable louvre windows in the external and corridor walls of each unit to promote cross-ventilation. Air flow along the corridors is generated by 'heat chimneys' which were created by placing a large black louvred 'box' at the top of the stairwells at each end of the building. When the black box is heated by the sun air is drawn up the stairwells from the Ground and Level 1 corridors. This creates a natural air flow across individual offices when the louvred windows are open on both the external corridor walls.

The top floor has been fitted with clerestory windows opened by heat sensors. This feature provides natural light and ventilation to the top floor.
The three storey atrium foyer in the centre of the building also acts as a heat chimney.

3. Reducing Water Consumption and Eliminating Sewage
Another design objective was to reduce water consumption and the greenhouse gases associated with pumping water to, and sewerage from, the site. Garigal has its own black water treatment plant to treat all sewage and recycle that water for flushing toilets and garden watering. Garigal is not connected to the Sydney Water sewerage system. Rainwater is collected to complement the supply of recycled water. Thousands of litres of high quality potable water can be saved each year (est. 1.3 million litres pa). This means strata owners will have low water bills and they will not have to pay sewerage rates.

What were the things that didn't work quite so well and how were they managed?

It was anticipated that the sewage treatment plant would not provide sufficient recycled water for garden watering as well as toilet flushing during the early occupation phase of the building. A 20,000 litre water storage tank was installed to collect rainwater for irrigation purposes. However, the abnormally high rainfall in eastern Australia due to the La Nina weather pattern in the Pacific provided much more water than could be collected. The native plants selected because they do not need very much water have benefitted greatly from the rain. They have grown rapidly and are now very well-established - and much larger than expected at this stage.

Unsightly green algae is growing and mosquitoes are breeding in the outdoor reflection pond that was installed as an architectural feature. The native fish that were put in the pond to eat the mosquito larvae and the moss were eaten by the native birds! It is not possible to chlorinate the water because the native plants in the pond would not survive. Attempts to clean the water with a sand filter have not been successful. We are still trying to find an ecological solution.

The top floor of the building is noticeably warmer than the two lower floors despite the effective natural cross-flow air conditioning system. Originally a white roof was proposed but the Council required a medium colour roof. For architectural reasons, the roof ended up a dark grey colour which is contributing to the heat load on the top floor.

The occupier's view - an interview with Craig Stokoe, Principal of LPN Design, occupant of Unit 16 (a suite made up of three standard strata units) in Garigal

April 2008

What are the main reasons why your company chose to develop a sustainable strata office building?

The criteria for the selection of a new home for our visual communications firm LPN Design included:

1. A building with demonstrable ability to consume markedly less energy than the norm for lighting and ventilation, and reduction of water consumption by recycling water.
2. Surroundings conducive to creative thinking. A relaxed, spacious environment for people working in a deadline-driven industry
3. Fellow occupants who shared our ideals.

After much searching, we determined Garigal was the most suitable due to a deliberate and extensive environmental awareness in its location and daily operation. Chief in its appeal is the positioning and outlook. Set back from the road and facing the park, it is unparalleled in providing an oasis of quiet in a city of four million.

The solar-activated shade curtains are a particularly effective initiative. These, combined with each unit having individual control of its air-conditioning, have seen us have to recourse to artificial cooling for only six half-days in over five months.

The absence of noise and doors to the expansive balcony and the constant bushland chorus has seen a noticeable improvement in LPNs internal communications and productivity.

My business partner and I had hoped for a lot with our choice of Garigal. It is no exaggeration to say it has yielded considerably more than we had expected.

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