Summary

1 Bligh St (also known as Space) will be 28 storeys high and has a total of 42 000 square metres of floor space. Dexus Property Group, one of Australia's largest property fund managers, is the owner, developer and investor. The building features a double skin façade and a range of progressive environmental design features, including the potential for natural ventilation, atriums and a range of energy and water initiatives.

The building will capture views to Circular Quay, Sydney and is due for completion in early 2011.

Owner: Dexus Property Group
Developer: Dexus Property Group
Investor: Dexus Property Group
Project Team Members:

• APP (project manager)
• Ray Brown of Architectus in association with Christoph Ingenhoven of Ingenhoven Architects (architects)
• Enstruct Group (structural)
• Arup and DS-Plan - Advanced Building Technologies (façade)
• Arup (electrical, mechanical and acoustic)
• Arup, Steve Paul and Partners (Hydraulic and fire)
• Sue Barnsley Design (landscape)
• Cundall (ESD consultant)
• Ryder Hunt (cost consultant)

Checklist of sustainable features

Energy
Indoor Environmental Quality
Productivity
Water
Waste
Materials
Transport

Motivations and lessons

The designer's view - an interview with Ray Brown, Architectus

1 August 2007

What are the main reasons why your company chose to do a sustainable building?

It's our preferred mode of operation and we have a long history of environmentally conscious buildings. It's just what we do.

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

We've been able to pursue innovative and holistic solutions in terms of the energy, sun shading and thermal comfort. In general we've had a holistic approach to the indoor environment quality.

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

There's a range of initiatives:

• The double skin façade allowed us to have a 100% shading solution while maintaining the views in most sections. The double skin has internal adjustable blinds.
• The building has been designed for the potential of natural ventilation to the perimeter of the building. But this feature is a tenant upgrade (considered in more detail in the next question).
• The treatment of water has certainly been a priority. Black water is treated on site and the water is used for landscape features such as the green walls and also for toilet flushing and cooling towers.
• There's a cogeneration plant in the building and also solar tubes for creating solar cooling.
• The atrium is another key element of the building and allows natural light deep into the floor plate. It adds a social hub and focus to the building and has balconies that project into the atrium to provide naturally ventilated break out spaces. Each floor has balconies between 30-50m projecting into the atrium.

  Typical floor plate showing layout and atrium (left); Cross section of the atrium (right).
  Source: Architectus
  

  
  
  

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

We're still in design, so obviously still working through the project. I guess we've got a very willing client but there's a disconnection between the end user for design purposes and the unspecified tenant that will occupy the building. This has two aspects.

Firstly, there's no ability to plug directly into the environmental aspirations of the would-be tenant when pitching to a wide market. In this case we may be missing opportunities if the actual tenants have very high aspirations.

Secondly, the performance of the design is largely dependent on the fit-out and how the tenants operate the building. Whatever you do in the base building is commendable but it comes down to the commitment of the tenants to achieve the star rating with the fit-out and use of the building. They may use a lot of air conditioning and be a power hungry tenant so it's very important the tenants are also educated. If you are going into a six star building then you want to have a six star fit-out. The building we're currently doing has the potential to be naturally ventilated, but, it is dependent on the fit-out from the tenant. The fit-out they choose could make the building fully air conditioned.

The biggest change has to happen in the property market. A big problem is the way the tenant's representative grade the buildings. Premium building standards require a a comfort band of 22-24 degrees Celsius and this needs to be discussed. It costs a lot of energy to achieve such a narrow band. A more realistic band would be, say, 22-26 degrees Celsius. This would save a lot of energy if the temperature outside is 35 degrees.

Other information and resources on 1 Bligh Steet

Green as an Aussie Cucumber, Tina Perinotto, Australian Financial Review, 18 July 2007
http://www.afr.com/home/

Dexus Property Group Sustainability Reporting
http://www.dexus.com/Sustainability.aspx