Leaders in sustainable design
In early 2018, Architectus and Germany’s ingenhoven architects identified the design competition for the residential development at 505 George Street as an opportunity to challenge this status quo. This project is being undertaken by Coombes Property Group as owner and developer with Mirvac as development manager. Together, the two practices conceived a 270-metre tower – Sydney’s tallest residential development – with the infrastructure to fully transition to renewables by 2030, a feat yet to be achieved in an Australian development of anything close to this scale.
Ingenhoven architects and Architectus came to this project with shared history. Opening in 2011, the two practices’ first collaboration, 1 Bligh Street was applauded as a global example of well executed sustainable design principles. That building was Australia’s first office tower with a full double-skin facade and a bold approach that provides natural ventilation, social interaction in the atrium spaces and natural daylight to office spaces. With its innovative and elegant design, the tower won a sweep of prestigious awards, including the 2012 Australian Institute of Architects NSW Awards’ Milo Dunphy Award for Sustainable Architecture. In 2019, it was named among the world’s 50 most influential tall buildings of the last 50 years by the Council on Tall Buildings and Urban Habitat.
Pushing the boundaries of green design
In the years since, both practices have continued pushing the boundaries of green design. Ingenhoven architects are global leaders in the field of sustainable architecture. Their substantial portfolio includes landmark projects such as Freiburg Town Hall, the world’s first public net-surplus-energy building, generating more energy than it consumes. Ingenhoven architects also championed the Architects Declare movement in Germany and is one of the ten founding members of the Architects Declare in Germany.
Among other breakthrough projects, Architectus is currently working on another significant collaboration with Singapore practice, WOHA to design a first principles green residential tower at Brisbane’s 433 Queen Street (Cbus Property). A thoughtful and specific response to Queensland’s sub-tropical climate, artists impressions of the proposed 5 Star Green Star development depict an almost utopic building, cooled by ocean breezes and draped head-to-toe in tropical greenery. Both practices’ achievements have been underpinned by a utopian refusal to rest on the laurels of past projects.
As we developed the design for 505 George, sustainability consultancy Cundall were commissioned to provide sustainability advice and analysis, including undertaking a comprehensive study of ESD initiatives in high-rise residential buildings around the world.
We hoped to uncover projects that would serve as a blueprint of sorts, but our findings were underwhelming. An analysis of 18 current and future tall residential building projects since 2014, spanning Australia, the United States, Asia and the Middle East, found few with environmental certification and most with fairly standard “green” initiatives: double-glazed facades, natural ventilation of apartments, regenerative lifts, external shading, energy efficient whitegoods and green walls. Less common features included rainwater harvesting, heat recovery systems, smart meters, and the elimination of fossil fuel generated energy.
Creating a sustainability framework
The project team went back to first principles and looked at key sustainability initiatives appropriate to the Sydney CBD location and climate leading us to a design incorporating the following initiatives:
- high-performance facade with clear glazing, external shading and innovative natural ventilation system, improving energy consumption and thermal comfort and reducing noise.
- significant green spaces (two sky gardens within the tower, a roof garden and green walls) contribute to the city’s biodiversity and connect residents to nature
- trialling a shower heat recovery technology which pre-heats cold water supplied to shower heads, reducing the amount of hot water required
- connection point to the recycled water pipe infrastructure installed in George Street to allow use of recycled water in the future for non-potable uses when the precinct recycled water system becomes operational
- secure bike storage and easy access to nearby public transport
- charging points for electric cars in five per cent of car parking bays with the option to increase this number to meet future demand
- during detail design phase, we will investigate the feasibility of the infrastructure required for future installation of batteries, should they become viable in high density buildings
- A hybrid domestic hot water system comprising heat pumps for base load and natural gas boost. As technology develops (both in efficiency and size) it is proposed to replace the gas boost system with heat pumps in the future to make the building fully electric
- No natural gas provided to any apartment. Cook tops will be induction type. To make this possible, Arup’s services engineers had to analyse in detail the peak electrical loads to stay within the capacity of the site’s two sub-stations.
Future-proofing for zero carbon
The elimination of natural gas from apartments and the reduction of gas elsewhere represents a significant milestone in Australia’s cities. This will enable the building to run on low carbon electricity as the grid decarbonises or 100% renewable energy by entering into a future Power Purchase Agreement (PPA).
505 George Street will become Australia’s tallest residential tower to receive a 5 Star Green Star Design and As-Built rating from the Green Building Council of Australia. The building will exceed the BASIX (Australia’s Building Sustainability Index) minimum targets for water and energy and is future proofed to become zero carbon.
Already, this project is making waves. In 2019, it won the MIPIM Architectural Review Future Project Award in the Tall Buildings category in Cannes, France and was named a finalist in the best future residential projects at the World Architecture Festival.
Like 1 Bligh Street, 505 George Street belongs to a rare class of building whose elegance is inextricably connected to a high-performance function. To achieve our high ambitions, the entire design team, with great support from the clients, hope that by future proofing the building and defining new benchmarks in the residential market, 505 George Street becomes a landmark project in these times of change.