JEAN NOUVEL
Photo by Murray Fredericks. Images courtesy of Frasers Property Australia and Sekisui House Australia. Published on November 06, 2014.
Global Overview
The United Nations predict that the world’s population will increase by 2 billion between today and 2050, and the number of people living in cities will rise from 50% to 75%. Inevitably, rural populations will be shrinking, and almost every urban center in the world will be growing. 21st Century Australia is not exempt from this trend: Sydney could grow from 4.6 million inhabitants today to 7 million by 2056, Melbourne from 4.1 to 6.8 million, Brisbane from 2 to 4 million and Perth from 1.7 to 3.4 million. In this demographic scenario, all these cities will have to house up to one million people within the next 20 years, or 4000 per month. Australia’s natural resources, arable land area and economic outlook make such a population increase very possible. The Australian government welcomes foreign real estate investments to cope with the existing shortage of 300,000 homes nationwide. Simultaneously, it encourages immigration of wealthy retirees, students, and highly skilled workers from abroad. The steady influx of funds and knowledge has made Australia one of the world’s top ten countries with the highest GDP’s per capita. Four Australian cities have recently risen into the top ten of the Economist’s Global Liveability Ranking of 2014.
The United Nations predict that the world’s population will increase by 2 billion between today and 2050, and the number of people living in cities will rise from 50% to 75%. Inevitably, rural populations will be shrinking, and almost every urban center in the world will be growing. 21st Century Australia is not exempt from this trend: Sydney could grow from 4.6 million inhabitants today to 7 million by 2056, Melbourne from 4.1 to 6.8 million, Brisbane from 2 to 4 million and Perth from 1.7 to 3.4 million. In this demographic scenario, all these cities will have to house up to one million people within the next 20 years, or 4000 per month. Australia’s natural resources, arable land area and economic outlook make such a population increase very possible. The Australian government welcomes foreign real estate investments to cope with the existing shortage of 300,000 homes nationwide. Simultaneously, it encourages immigration of wealthy retirees, students, and highly skilled workers from abroad. The steady influx of funds and knowledge has made Australia one of the world’s top ten countries with the highest GDP’s per capita. Four Australian cities have recently risen into the top ten of the Economist’s Global Liveability Ranking of 2014.
Photo by Murray Fredericks. Images courtesy of Frasers Property Australia and Sekisui House Australia. Published on November 06, 2014.
One Central Park near Central Station in Sydney is one development that demonstrates how Australia’s urban growth is materializing. Until recently, rapid new construction and short housing supply fuelled a conservative culture of cheap and fast projects that favored minimal risk over design quality. But this tradition is being challenged by three factors: political pressures to invest in Sydney’s future, international developers willing to invest in higher quality architecture, and buyers’ growing demand for signature design. OCP benefits from all three of these drivers. It is a State Significant Development under the direct approval authority of the Minister of Planning and as such a public quality benchmark. The developer, Frasers Property Australia, has a track record for excellence in design and a potent financial partner in Sekisui House from Japan. The core planners and architects (Foster + Partners from London, Ateliers Jean Nouvel from Paris and Johnson-Pilton-Walker from Sydney) were selected for their global expertise with high density urban sites and their innovative practices. As an indication of new buyers’ confidence in innovative design, 90% of OCP’s initial apartments sold off-plan within a three month record time, and the project was completed on schedule and on budget at AU$ 5 400/m².
Photo by Murray Fredericks. Images courtesy of Frasers Property Australia and Sekisui House Australia. Published on November 06, 2014.
Planning and Design
One Central Park is the first stage of the AU $2 Billion Carlton & United Brewery site redevelopment near Central Station in Sydney. Foster + Partners coordinated the overall master plan with the understanding that Sydney’s population will keep growing and that residential towers near inner city traffic nodes are a more viable lifestyle choice than suburban sprawl, because they waste less energy, less farmland, and less money for infrastructure and transportation. The development’s massive size drives economies of scale that allow investments in a 30MW Central Thermal Plant (CTP), a 2MW tri-generation system and a 1ML/day black water treatment plant. The recovered thermal energy and power make the overall development more energy efficient, and the recycled water can be used for the Thermal Plant, irrigation and domestic residential needs. These planning choices are consistent with the targets set out by the Green Building Council of Australia in its Green Star rating system for retail and multi-unit residential projects, and all individual projects of the master plan adhere to it. Since traditional residential high rises in Sydney’s climate have a record of poor energy performance, all outdated design criteria have been reconsidered. As a result, One Central Park achieves a rating of five under the Green Star system, which represents a 26% improvement over New South Wales average energy consumption. This success comes with the sobering realization that the project’s compliance alone would have been barely perceptible to the public. Strategic planning decisions – building high density in the right location – go unnoticed or are taken for granted. The most important sustainable features – onsite power and recycling plants – are underground or out of sight. Exposure control, self-shading, high performance glass and natural ventilation are all crucial for a superior energy performance, but don’t result per se in anything architecturally distinctive.
One Central Park is the first stage of the AU $2 Billion Carlton & United Brewery site redevelopment near Central Station in Sydney. Foster + Partners coordinated the overall master plan with the understanding that Sydney’s population will keep growing and that residential towers near inner city traffic nodes are a more viable lifestyle choice than suburban sprawl, because they waste less energy, less farmland, and less money for infrastructure and transportation. The development’s massive size drives economies of scale that allow investments in a 30MW Central Thermal Plant (CTP), a 2MW tri-generation system and a 1ML/day black water treatment plant. The recovered thermal energy and power make the overall development more energy efficient, and the recycled water can be used for the Thermal Plant, irrigation and domestic residential needs. These planning choices are consistent with the targets set out by the Green Building Council of Australia in its Green Star rating system for retail and multi-unit residential projects, and all individual projects of the master plan adhere to it. Since traditional residential high rises in Sydney’s climate have a record of poor energy performance, all outdated design criteria have been reconsidered. As a result, One Central Park achieves a rating of five under the Green Star system, which represents a 26% improvement over New South Wales average energy consumption. This success comes with the sobering realization that the project’s compliance alone would have been barely perceptible to the public. Strategic planning decisions – building high density in the right location – go unnoticed or are taken for granted. The most important sustainable features – onsite power and recycling plants – are underground or out of sight. Exposure control, self-shading, high performance glass and natural ventilation are all crucial for a superior energy performance, but don’t result per se in anything architecturally distinctive.
Photo by Murray Fredericks. Images courtesy of Frasers Property Australia and Sekisui House Australia. Published on November 06, 2014.
After finally having begun to acknowledge and address climate change with sustainable design in our cities, it still doesn’t really seem to show. Perhaps the challenge here is to communicate the importance of an imaginary gas that we shouldn’t emit. We cannot see or feel CO2, and this invisibility alone translates poorly into architecture. As a result, there is an abysmal gap between the collective idea of green buildings and the built reality. The clichés of green roofs and parks instantly suggest sustainability, but account for no more than 4% of obtainable Green Star credits, and depending on irrigation, maintenance and purpose, may be entirely unsustainable. Without background information or expertise, it can be difficult to distinguish a zero net energy project from the most wasteful buildings standing right next to it. So, in order to transform environmental commitments into visible architecture, it seems that the design approach has to widen, go beyond the rating checklists and invent new technical solutions that may not yet get credited, but still push the performance beyond the requirements and are clearly visible to anyone. These technologies have to work with the popular culture of our time and use it to the advantage of the project: they have to be useful and produce a better human experience than the engineered box. One Central Park integrates two such technologies – hydroponics and heliostats – deep into its design and infrastructure, and then deploys them in direct relation to the site. Hydroponics allows using the recycled water from the black water treatment plant to irrigate plants that can grow on tower facades in very shallow slab edge planters or on thin vertical green walls. Heliostats make it possible to bring programmable amounts of direct sun into shaded areas of the project for light and heat. Both of these technologies have a long ecological history and have turned via mass fabrication over the past twenty years from exotic experiments into commonplace methods of sustainable agriculture and energy generation. The proven performance and affordability of these systems is therefore a readily available resource for architecture, but it hasn’t found its applications yet.
Photo by Murray Fredericks. Images courtesy of Frasers Property Australia and Sekisui House Australia. Published on November 06, 2014.
The central focus of the Master Plan is a public park that branches out into smaller green pockets in each individual development and stands as a powerful popular symbol for the overall sustainable design goals of the development. This open green space materializes the conviction that any major new increase in urban density should in turn be matched by a significant new public space for recreation. In order to make room for such a park where there was none before, some building mass has to be lifted off the ground and concentrated along Broadway on the North border of the site. This configuration keeps the development low on the South side where it would otherwise overshadow the adjacent small scale residential neighborhood of Chippendale. The tall massing on the North side of the site creates however the double challenge of obstructing the park’s visibility from the city’s main approach and overshadowing it with tall buildings.
Photo by Murray Fredericks. Images courtesy of Frasers Property Australia and Sekisui House Australia. Published on November 06, 2014.
The new park is relatively modest compared to Sydney’s Hyde Park or Botanical Garden, but the local residents are proud of it, and its visibility is important to them. The primary design challenge is then to give a small neighborhood park a big citywide presence, and the most effective way to do this is to bring its vegetation up into the sky along the tower facades where it will be visible in the city from afar. Since the project needs to address two very different neighborhoods next to it, this verticalization of the park takes two forms. On the North, East and West sides, the green takes a continuous veil-like appearance with green walls, linear planter bands and climbing vegetation on cables spanning vertically over several floors. This monolithic landscape appearance is the downtown façade of the project, facing the University of Technology’s tall inner city campus and Broadway’s intense traffic. On the South side, facing Chippendale’s small scale residential neighborhood, the park rises in a sequence of planted plateaus and randomly scattered puzzle pieces across the facades, giving them texture and depth. The planted shelves and balconies of each apartment appear as private islands breaking away from the monolithic mass of the public park. From close up, they form a cascade of individual garden fragments, but from further away, they converge into a pointillistic vertical landscape. The Tower in the Park is also a Park in the Tower.
Photo by Murray Fredericks. Images courtesy of Frasers Property Australia and Sekisui House Australia. Published on November 06, 2014.
A second design challenge that arises from the tall massing along the north side of the site is the towers’ shadow and the lightless depth inside the podium block. In order to remediate the lack of direct sunlight south of the building, the volume is broken up into a lower and a taller tower on a five story podium. On the roof of the lower tower, 40 sun tracking heliostats redirect sunlight up to 320 reflectors on a cantilever off the taller tower, which then beam the light down into an atrium, onto a pool deck and into the overshadowed areas. Because of the project’s massing, the atrium would receive no more than a few minutes of direct sunlight in the summer. With the heliostats however, it can be naturally lit all year for any amount of time as long as the sun shines. The motion controls of the heliostats are programmed to adapt hourly and seasonally to the needs for brightness and warmth in each place, so that the dappled lights can follow their daily choreography across the site in the most useful way. At night, LED lights on the 320 reflector facets create a monumental urban chandelier that simulates reflections of glittering water from the nearby harbor. On a full moon night, the heliostats redirect forty reflections of the moon and make them visible in the park.
Photo by Murray Fredericks. Images courtesy of Frasers Property Australia and Sekisui House Australia. Published on November 06, 2014.
Sustainable Strategies
OCP’s overall planning intent is to follow and exceed the highest design standards of the Green Buildings Council of Australia under its Green Star rating system for retail and multi-unit residential projects. The project’s innovative use of hydroponics and heliostats showcases the vision of an environmentally ambitious future for Sydney. In order to meet this agenda, OCP’s planning and design revolves around six core strategies.
• Urban Density: OCP creates apartments where they’re really needed. If Sydney’s population is to grow by 4000 new inhabitants per month, residential towers near inner city job and transportation centers will be more sustainable than planless sprawl with no adequate public transportation in Sydney’s Inner Western suburbs. OCP is within a 10 minute walking distance from Sydney’s Central Business District and two of the three major universities. It is also located directly near Central Station, one of Sydney’s busiest public transportation nodes. In line with Green Star recommendations, OCP’s underground resident parking is limited to state required minima.
• City of Parks: Sydney was conceived by its founders as a city of parks. Today, this wise foresight benefits the urgent need for pockets of decompression and decongestion in Sydney’s ever denser inner city blocks. OCP continues the city’s evolution in this direction by putting another new park on the green map and amplifying its presence in the skyline.
• Exposure: Sydney’s climate type is temperate bordering on subtropical with mild, wet winters and very hot summers. Because of the summer sun’s intensity, OCP’s massing is designed to minimize thermal exposure without sacrificing façade transparency. The two largest facades are running East-West, so that one of them faces South and receives almost no direct sun while the other one faces North and can be easily protected from high noon sun with 600mm deep horizontal shelves that immediately reduce the heat gains by 20%. The podium-plus-two-towers configuration maximizes self-shading between the towers in the morning and afternoon. A 40m cantilevering skygarden and giant facetted reflector function as a baseball cap to provide shade for the upper West façade of the taller tower where it can’t be overshadowed by the lower one. The overall volume concedes greater block depth to reduce the façade area and thereby the heat gains, which in turn allows for more glazing. Deep vertical slots are carved into the mass to allow for light and air far into the block, as well as sporadic views from the main circulations on every floor. The intentional massiveness of the project is an expression of its thermal behavior and relates proportionally to the park and UTS campus. It matches the much smaller scale of its distant residential Chippendale neighbors in its façade texture rather than its overall proportions.
• Green Star: OCP improves the usually poor energy performance of residential high rises to meet a rating of at least five under the Australian Green Star standards and achieve a 26% reduction in energy consumption compared to the average in New South Wales. During planning, this performance is tracked through a BASIX energy model and the Green Star compliance checklist. After completion, the as-built conditions are recorded and filed for final certification.
• Organic Shading: OCP improves on its cooling energy waste with a system of 5 km long linear slab edge planters that function like permanent shading shelves and reduce thermal impact in the apartments by about 20%. Additional shading from the plant foliage can further diminish heat gains by an additional 20% depending on location and plant species. As opposed to fixed mechanical shades, foliage cover can’t easily be predicted and quantified, and it therefore can’t be accounted for in theBASIX calculations or Green Star checklist. By contrast to metallic louvers, the plants trap Carbon Dioxide, emit Oxygen and reflect less heat back into the city. Instead of maintaining and cleaning kilometers of external louvers, the body corporate of the towers’ residents employs a gardener who prunes and cares for the vegetation. The choice of the species is critical for the success of the system, because some of the façade’s microclimates have extreme levels of sun and wind exposure. For this reason, the French botanist Patrick Blanc was entrusted with the selection of the 350 species that populate the facades. His expertise is based on his 30-year long career as a research scientist focusing on plant survival in soil-less and harsh climatic conditions, as well as his ground breaking invention and patent of the Vertical Garden concept.
Since the plants climb on vertical steel cables from slab to slab, their leaves are ideally positioned for shading even on western exposures, and they can be custom tailored to the thermal needs of each resident. The plants grow in Polyethylene planter boxes that are roto-molded into proprietary double wall containers to assure proper drainage and avoid bacterial and fungal buildup in the substrate. Polyethylene can be recycled, processed back into oil or biodegraded by pseudomonas fluorescens bacteria. The plants are grown hydroponically in a substrate for mechanical root adhesion and are irrigated with water from the on-site storm water collection tanks and the central recycling plant. A central mixing unit then adds minerals and fertilizers to the water and distributes it according to the specific needs of each façade area, based on its microclimate and the selected species. Programmable solenoids regulate the released water amounts at local control centers based on weather data like air humidity, wind, temperature and presence of sun. Overall, the towering veils of plants turn the green cliché of sustainability into a functional and conceptual part of the infrastructure: the building organically grows its own shading with its own recycled water and saves cooling energy.
• Solar Energy: OCP features a thermal solar power system. 40 heliostats (sun tracking mirrors) on the lower tower reflect direct sunlight up to 320 Fresnel reflectors on a cantilever off the taller tower, which then beam the light down into an atrium, onto a pool deck and into the park. A layer of water on the atrium glass roof functions as a drainable heat filter. It absorbs the infrared spectrum of the direct sunlight in the summer and naturally cools down by evaporation. In the winter the roof pond can be drained, so that the sunlight can help heat the space below for precisely programmable times and durations of each day. The heliostat system adapts hourly and seasonally to the needs for brightness and warmth in each place by shifting the light where it is the most useful. Like a baseball cap, the cantilevered reflector shades the East Tower façade, while the heliostats on the West Tower massively reduce heat loads to the roof. The system redirects up to 200m² of direct sunlight and utilizes approximately between 40% and 60% of the corresponding power during Sydney’s 2600 annual sunshine hours. This is a relatively high efficiency, because solar power is being used directly for light and heat instead of first being converted into electricity. Because the output energy of this experimental system has to be empirically measured in the built project, its performance could not be accounted for in the BASIX (Building Sustainability Index of New South Wales) and Green Star calculations.
OCP’s overall planning intent is to follow and exceed the highest design standards of the Green Buildings Council of Australia under its Green Star rating system for retail and multi-unit residential projects. The project’s innovative use of hydroponics and heliostats showcases the vision of an environmentally ambitious future for Sydney. In order to meet this agenda, OCP’s planning and design revolves around six core strategies.
• Urban Density: OCP creates apartments where they’re really needed. If Sydney’s population is to grow by 4000 new inhabitants per month, residential towers near inner city job and transportation centers will be more sustainable than planless sprawl with no adequate public transportation in Sydney’s Inner Western suburbs. OCP is within a 10 minute walking distance from Sydney’s Central Business District and two of the three major universities. It is also located directly near Central Station, one of Sydney’s busiest public transportation nodes. In line with Green Star recommendations, OCP’s underground resident parking is limited to state required minima.
• City of Parks: Sydney was conceived by its founders as a city of parks. Today, this wise foresight benefits the urgent need for pockets of decompression and decongestion in Sydney’s ever denser inner city blocks. OCP continues the city’s evolution in this direction by putting another new park on the green map and amplifying its presence in the skyline.
• Exposure: Sydney’s climate type is temperate bordering on subtropical with mild, wet winters and very hot summers. Because of the summer sun’s intensity, OCP’s massing is designed to minimize thermal exposure without sacrificing façade transparency. The two largest facades are running East-West, so that one of them faces South and receives almost no direct sun while the other one faces North and can be easily protected from high noon sun with 600mm deep horizontal shelves that immediately reduce the heat gains by 20%. The podium-plus-two-towers configuration maximizes self-shading between the towers in the morning and afternoon. A 40m cantilevering skygarden and giant facetted reflector function as a baseball cap to provide shade for the upper West façade of the taller tower where it can’t be overshadowed by the lower one. The overall volume concedes greater block depth to reduce the façade area and thereby the heat gains, which in turn allows for more glazing. Deep vertical slots are carved into the mass to allow for light and air far into the block, as well as sporadic views from the main circulations on every floor. The intentional massiveness of the project is an expression of its thermal behavior and relates proportionally to the park and UTS campus. It matches the much smaller scale of its distant residential Chippendale neighbors in its façade texture rather than its overall proportions.
• Green Star: OCP improves the usually poor energy performance of residential high rises to meet a rating of at least five under the Australian Green Star standards and achieve a 26% reduction in energy consumption compared to the average in New South Wales. During planning, this performance is tracked through a BASIX energy model and the Green Star compliance checklist. After completion, the as-built conditions are recorded and filed for final certification.
• Organic Shading: OCP improves on its cooling energy waste with a system of 5 km long linear slab edge planters that function like permanent shading shelves and reduce thermal impact in the apartments by about 20%. Additional shading from the plant foliage can further diminish heat gains by an additional 20% depending on location and plant species. As opposed to fixed mechanical shades, foliage cover can’t easily be predicted and quantified, and it therefore can’t be accounted for in theBASIX calculations or Green Star checklist. By contrast to metallic louvers, the plants trap Carbon Dioxide, emit Oxygen and reflect less heat back into the city. Instead of maintaining and cleaning kilometers of external louvers, the body corporate of the towers’ residents employs a gardener who prunes and cares for the vegetation. The choice of the species is critical for the success of the system, because some of the façade’s microclimates have extreme levels of sun and wind exposure. For this reason, the French botanist Patrick Blanc was entrusted with the selection of the 350 species that populate the facades. His expertise is based on his 30-year long career as a research scientist focusing on plant survival in soil-less and harsh climatic conditions, as well as his ground breaking invention and patent of the Vertical Garden concept.
Since the plants climb on vertical steel cables from slab to slab, their leaves are ideally positioned for shading even on western exposures, and they can be custom tailored to the thermal needs of each resident. The plants grow in Polyethylene planter boxes that are roto-molded into proprietary double wall containers to assure proper drainage and avoid bacterial and fungal buildup in the substrate. Polyethylene can be recycled, processed back into oil or biodegraded by pseudomonas fluorescens bacteria. The plants are grown hydroponically in a substrate for mechanical root adhesion and are irrigated with water from the on-site storm water collection tanks and the central recycling plant. A central mixing unit then adds minerals and fertilizers to the water and distributes it according to the specific needs of each façade area, based on its microclimate and the selected species. Programmable solenoids regulate the released water amounts at local control centers based on weather data like air humidity, wind, temperature and presence of sun. Overall, the towering veils of plants turn the green cliché of sustainability into a functional and conceptual part of the infrastructure: the building organically grows its own shading with its own recycled water and saves cooling energy.
• Solar Energy: OCP features a thermal solar power system. 40 heliostats (sun tracking mirrors) on the lower tower reflect direct sunlight up to 320 Fresnel reflectors on a cantilever off the taller tower, which then beam the light down into an atrium, onto a pool deck and into the park. A layer of water on the atrium glass roof functions as a drainable heat filter. It absorbs the infrared spectrum of the direct sunlight in the summer and naturally cools down by evaporation. In the winter the roof pond can be drained, so that the sunlight can help heat the space below for precisely programmable times and durations of each day. The heliostat system adapts hourly and seasonally to the needs for brightness and warmth in each place by shifting the light where it is the most useful. Like a baseball cap, the cantilevered reflector shades the East Tower façade, while the heliostats on the West Tower massively reduce heat loads to the roof. The system redirects up to 200m² of direct sunlight and utilizes approximately between 40% and 60% of the corresponding power during Sydney’s 2600 annual sunshine hours. This is a relatively high efficiency, because solar power is being used directly for light and heat instead of first being converted into electricity. Because the output energy of this experimental system has to be empirically measured in the built project, its performance could not be accounted for in the BASIX (Building Sustainability Index of New South Wales) and Green Star calculations.
Photo by Murray Fredericks. Images courtesy of Frasers Property Australia and Sekisui House Australia. Published on November 06, 2014.
Conclusions
The plants growing on One Central Park’s tower facades are neither a romantic, nor a picturesque reference. If anything, the project displays an unsentimental intention to keep architecture and nature in a dialog. The modernist separation of the two appears forced in Sydney’s climate, and it’s difficult to understand why so many high rises in this city still imitate the generic curtain-walled skyscrapers from America’s cold north. In this context, the contamination of architecture’s rigid framework with nature’s living complexity appears to be a risk worth taking. Beyond the mere function of shading apartments, the towering green presence of the building’s 180,000 plants is also a universal sign of life on Earth. The knowledge that vegetation means life is so deeply engrained in human consciousness that parks and gardens have at all times been the most desirable places to live next to. In their absence, the potted plants on lonely city balconies, so dreaded by the modern purists, have long born witness to a human preference for the company of living flowers to that of concrete and glass.
The plants growing on One Central Park’s tower facades are neither a romantic, nor a picturesque reference. If anything, the project displays an unsentimental intention to keep architecture and nature in a dialog. The modernist separation of the two appears forced in Sydney’s climate, and it’s difficult to understand why so many high rises in this city still imitate the generic curtain-walled skyscrapers from America’s cold north. In this context, the contamination of architecture’s rigid framework with nature’s living complexity appears to be a risk worth taking. Beyond the mere function of shading apartments, the towering green presence of the building’s 180,000 plants is also a universal sign of life on Earth. The knowledge that vegetation means life is so deeply engrained in human consciousness that parks and gardens have at all times been the most desirable places to live next to. In their absence, the potted plants on lonely city balconies, so dreaded by the modern purists, have long born witness to a human preference for the company of living flowers to that of concrete and glass.
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