Mirvac’s new workplace at its recently completed 200 George Street tower will provide the company with a “living laboratory” to test out technologies and approaches that improve sustainability, according to Mirvac Senior Development Manager, David Chan.
The building has already achieved a 6 Star Green Star Office Design v3 rating, and is targeting a 6 Star Green Star As Built v3, 5 Star NABERS for energy, 4 Star NABERS for Water and a WELL Gold rating for the Mirvac fitout. The company has signed a 10 year lease on 6,865 square meters over five floors.
EY has also signed a 10 year lease on 25,850 sqm metres of space, which includes two levels with open-air greened terraces.
The building was developed and built by Mirvac, and the Mirvac Property Trust retains 50 per cent ownership with the balance of ownership belonging to AMP Capital Wholesale Office Fund.
The 37-level tower designed by FJMT features a pressurised high performance closed cavity facade with timber blinds within the floor-to-floor integrated glazing units that comprise the building’s skin. The blinds respond to light conditions to reduce glare and thermal loads, Chan says.
The whole system is automated through the building management system. Tenants have the ability also to override the automation for direct control. Chan says in its own space, the company has integrated the blind controls with the audio-visual systems for manual override when required.
In terms of the aesthetic of the building, Chan says the timber was a feature of FJMT’s winning design competition entry.
FJMT director Richard Francis-Jones has commented that “most city buildings look like they are wearing sunglasses…like security guards,” Chan says. The timber element gives the building a more warm and organic look.
The use of timber blinds was something approached with great care, with a great deal of research and modelling, Chan says. As long-term owners of the property, there was a need to be sure the product would last.
The blinds are made from New Zealand grown radiata pine that has been treated with acetic acid, high temperatures and pressure to create a highly durable wood product.
The blinds were inserted into the facade units during their assembly in Thailand. The units also comprise double-glazing on the inside and low-iron high-performance clear glass on the outside. They were pressurised lightly during manufacture before being transported to the site.
During construction, a temporary pressurisation system was installed to maintain the system.
Chan says that using the prefabricated units was “one less complexity we had to deal with on-site.”
To maintain the pressure during the building’s life, as the air inside the units expands and contracts with temperature changes, a small hose on each unit supplies dehumidified air at low pressure through the central plant system. This will also prevent the units pulling in dust or other contaminants, he says.
The project’s mechanical, hydraulic and electrical systems engineering design was carried out by Arup, which was also the sustainability consultant on the project.
The building’s HVAC system incorporates a perimeter active chilled beam system and in the central areas a low temperature VAV system.
Chan says that using the active chilled beams reduces the number of risers that had to be installed, and also due to their smaller size compared to passive chilled beams, provide greater flexibility for tenant fitouts. The solution as a whole is also more energy efficient, he says.
The building has a small rainwater capture and reuse system. Chan says the decision was made not to install a blackwater treatment system as the site’s location near the top of the CBD sewer system would make the system ineffective.
The captured rainwater will be used for irrigation of the green elements on the EY tenancy terraces, and also for watering ground floor greening. It will also supply the cooling towers.
The company’s own tenancy incorporates a substantial number of plants, as part of targeting the WELL Gold rating. There are around 1400 plants throughout the tenancy, in a combination of green walls, plantings and individual pot plants.
Tenants encouraged to install sustainable fitouts
Tenants will be encouraged to use sustainability guidelines in their fitouts and the company is also aiming to incorporate Green Star objectives into the leases. There are elements of Green Star that apply to the company as both owner and tenant, Chan says.
The building management will be retained in-house and the FM team was made part of the whole development process, including design philosophy decision, delivery strategy and the building commissioning.
Other sustainability initiatives in the building include 100 per cent LED lighting throughout both base building and tenancies, believed to be a first for Sydney.
As part of the base building provision, the open-plan tenancies include full services and finishes carpet tiles and ceiling tiles that are low VOC.
Way more bike spaces than car parking
The building has only 68 tenant car parking spaces, but 260 bicycle parking spaces for tenants plus another 56 bike parking spaces for visitors. The car park has provision for electric vehicle charging points, and one of the tenants has already planned to extend on that and install full charging facilities.
The end of trip facilities include 260 lockers, 26 showers, a towel service, ironing boards, hair dryers and a bike service station.
Chan says the reduced provision for cars reflects the City of Sydney policy to reduce car parking in order to encourage active and low-carbon transport options. The building’s location means there will be light rail passing the front entrance, and a stop just nearby.
The ground floor of the building includes multiple public areas. There is an Italian bistro, two food and coffee places, a bar and the lobby incorporates public art and heritage interpretation elements. A painting by Indigenous artist Judy Watson reflects both the Indigenous and European history of the site, Chan says.
There is also a display on the building’s forecourt of heritage artefacts found on the site during the pre-construction archaeology dig. Sandstone unearthed during the excavation process has been repurposed within the building also, such as the lift lobbies.
Façade engineer Surface Design will continue to consult and SAMBA will test
The project’s facade engineers, Surface Design, will continue to consult with the company for ongoing sustainability initiatives in the fitout, including the targeted WELL and NABERS ratings.
Chan says the company’s tenancy has already installed SAMBA units to monitor indoor environment quality beyond the CO2, temperature and humidity monitoring that is part of the base building services.
“We are curious to know how our fitout stands up,” Chan says.
SAMBA data and other monitoring will provide evidence of whether the building is performing the way the design paperwork predicted.
“One of the things we have pursued is a strategy on smart buildings,” Chan says.
This means making information available that can be analysed within the “living lab” to see the impact of changes in how things are operated and other factors. That in turn will inform the company on what can be done to ensure buildings are operating effectively.
Chan says that the living lab approach also enables the company to test things out for itself to see what could be valuable for future projects.
Mirvac’s chief executive and managing, Susan Lloyd-Hurwitz says the company’s workplace is similar to the design of the award-winning 8 Chifley office tower, with floors linked by a central atrium for vertical connectivity and natural light.
The new workplace has no assigned desks or offices, and an activity-based working approach has been implemented.
Lloyd-Hurwitz says the space will promote “high levels of interaction and information sharing” and support.”
“200 George Street is the perfect canvas for Mirvac to showcase our ability to deliver an integrated real estate solution, that can generate cost and operating efficiencies,” Lloyd-Hurwitz says.