Nowhere is sustainability more important than in our growing metropolises. In this column we will be bringing you views and up to the minute news from experts and leaders in the field. If you would like to contribute please contact email@example.com
- 400m Imperial Tower designed by Adrian Smith + Gordon Gill
- Interview: Jenni Reuter
- Q&A(rchitect): A discussion on how emerging architects see the future of our profession
- Souta de Moura defies critics and accepts Israel’s Wolf Prize
- Israel and the Architectural Narrative
- High-Performance Facades: Performance Attributes – What to Consider & Measure
- Interview: Peter Rich
- The Face of the Future: Façade Engineering and Environmental Performance
Mic Patterson (President & Director of Strategic Development for Enclos) and Jennie Matusova (Zaha Hadid Architects)
Article originally published 7 March 2013 at enclos.com
While Extended Industry Standard Architecture (EISA) develops a set of attributes for high performance and green high performance, qualitative terms like “integrates, optimizes and outperforms” are subjective and relative measures that yield no concise metrics for evaluation. The National Institute of Building Sciences (NIBS) is one of the organizations working to define these needed metrics, baselines, benchmarks and verification strategies, specifically with respect to the building envelope. The building envelope is the nexus of many, often conflicting, functional demands, or as NIBS states: “many high-performance attributes interact at the envelope” (National Institute of Building Sciences n.d., 4). NIBS has leveraged EISA 2007 to define a set of performance attributes relevant to the building envelope, with an emphasis on enhanced security. The following attributes are similarly derived.
Attributes for Determining Performance of the Building Facade
Building energy performance is significantly impacted by various attributes of the facade. The building skin provides thermal insulation, mitigates air infiltration and controls solar energy radiation, providing daylighting opportunities to reduce electricity consumption and heating loads resulting from artificial lighting. Solar energy harvesting technologies will one day contribute to net-zero and net-plus energy buildings. Natural ventilation through the facade can play a significant role in building energy efficiency.
Environmental impacts of the building facade include energy consumption and resulting emissions over the operations phase of the building lifecycle, as well as larger, more lasting impacts. The lifecycle context requires that embodied energy, disassembly and end-of-life impacts also be considered. Waste generation through the building lifecycle is another important consideration.
Safety and security are provided to the building occupant by the facade systems (at the most fundamental level, keeping bugs and burglars out, and babies in). Protection from weather extremes includes impact resistant design practices. Blast loading criteria is now commonplace in facade design. NIBS references ballistic, chemical, biological and radiological protection.
Durability is an often neglected but fundamental aspect of performance and sustainability for all building systems, with special significance for the facade in its protective role of separating inside from out. In the majority of cases, a predicted service life for a building and its facade system goes undefined. Most damage and deterioration in a building can be traced to moisture penetration and migration through the building skin. Weathering is a particular concern for the exposed elements of the facade. Renovation requirements should be anticipated and planned for over the full building lifespan.
Cost-benefit, or economic efficiency, is yet another important performance consideration, which takes into account at what cost performance attributes are being amplified, verses the benefit the improvement provides. High performance and green programs are often motivated by promotional and image interests (greenwashing) and may ignore simpler and less costly solutions capable of providing equal or greater benefit at less cost, solely because they do not provide a high-profile green “wow” factor.
Human comfort, health, and productivity are profoundly affected by the facade system. The facade provides thermal and acoustical comfort, daylight, visual comfort and glare control, as well as connection to the natural environment. Natural ventilation through the facade can greatly enhance indoor air quality. Favorable biophilic facade attributes are well documented in providing a more productive and healthier indoor environment (Terrapin 2012). Even small improvements in productivity can quickly trivialize related first costs.
Sustainability criteria are included by the EISA in evaluation of high-performance systems. This opens the evaluation to the wide and varied considerations – and the inexact science – of sustainability. Many of the issues discussed here are fundamental sustainability issues. These considerations also include emergent issues like resilience, or the ability of a system to withstand extreme and unanticipated future conditions. Sustainability considerations will drive future development of facade technology. Water harvesting, for example, will become an increasingly important function of the facade in many geographic areas as supplies of potable water diminish. Lifecycle Assessment (LCA) will become the framework for the sustainability metrics that will drive future development of facade technology.
Operational considerations for the building facade include its integration with other building systems, the user interface, and maintenance and renovation requirements over the operational phase of the building lifecycle. Provisions must be considered to keep a building operational during planned renovation cycles, including disruptions to fuel and water supply, extreme weather conditions, and political instability.
Using the EISA definition then, a high-performance facade would be one that integrates and optimizes the above attributes on a lifecycle basis. A high-performance green facade is a high-performance facade that outperforms similar buildings with respect to key sustainability metrics as described above, again, on a lifecycle basis. Context, however, will determine the attribute set and the priority of those attributes as represented by the project specific criteria adopted for each attribute.
The EISA definition effectively leaves no performance attribute off the table when it comes to evaluating high-performance systems. But is it reasonable to “integrate and optimize” all of these attributes in each application? What if a facade application optimizes one area–energy efficiency, for example, but ignores durability analysis or acoustical performance? What about greenwashing? If a facade design employs high-performance materials and technology in an application where near equivalent performance could have been achieved with a simpler and less costly strategy (i.e., an expensive double-skin system where triple-glazed IGUs would have sufficed), is the system still deserving of the high performance designation? One begins to recognize how easily the term high performance may be applied with inadequate discrimination. High performance and green are terms that should be protected from dilution of meaning by clear definition and standards of practice.
While helpful to have some relevant performance attributes identified, related metrics are still lacking. The evaluation of some of these attributes may be inherently subjective, while others lend themselves to quantitative measure. In either case, appropriate evaluation criteria must be developed.
National Institute of Building Sciences n.d. “High Performance Based Design of the Building Envelope.” Accessed 11 February 2013: http://c.ymcdn.com/sites/www.nibs.org/resource/resmgr/HPBC/HPBDE_Workshop-Project_Overv.pdf
Terrapin 2012. The economics of biophilia: Why designing with nature in mind makes financial sense. New York: Terrapin Bright Green, LLC. Accessed 8 June 2012:
© Enclos Corp 2013
Sanjeev Tankha, Facades Group at Buro Happold West Coast
In an era defined by a need to do more with less, new approaches to facade design offer an optimistic counterpoint to tight construction budgets and climate change. As advances in computational design and analysis enable greater integration between building components, facade design has shifted focus from aesthetics and waterproofing to a pursuit of optimal building performance that encompasses design intent, structural efficiency, interior comfort, and energy performance. Most critically, this systems approach allows for a win-win scenario—vastly improved performance while controlling costs. Lessons learned from recent projects suggest that taking these innovations to the next level will demand a concurrent re-conceiving of traditional boundaries between disciplines.
The future today. Envisioned as a symbol of California’ leadership, the Anaheim Regional Transportation Intermodal Center (ARTIC) will serve regional transit lines including Amtrak, Metrolink, Greyhound and OCTA as well as the state’s future high-speed rail network. Undertaken in 2009, a time of heightened public scrutiny of project budgets, the $184m, 67,000 sq ft project demanded some new thinking, tools and technologies.
The complex geometry of ARTIC’s enclosure establishes the public facility’s iconic resonance, but it also composes a large percentage of the construction cost, making it imperative that the facade achieve levels of efficiency not possible through conventional design processes. Facade design used to prioritize structural efficiency; giving environmental performance equal weight forced new considerations and a new parameter for optimization.
Based on initial analysis, the design team led by HOK zeroed in on a three-part enclosure system composed of a structural glass high transparency wall, metal rain screen system, and ETFE roof cladding system, a light-weight, translucent fluorine-based insulating polymer. The facade team developed 14 unique scripts and routings to enable interoperability between software programs. This integration allowed the team to model for architectural visualization, material structural analysis, energy and daylight simulation, lighting simulation, geometric rationalization, clash coordination, cost estimation, digital fabrication and construction sequencing. Because ETFE’s thermal and structural performance relies on the air pressure of its cushions, the integrated modeling was crucial to gaining approval of its use, especially given its unprecedented scale for North America.
While familiar in Europe, use of ETFE remains relatively uncommon in United States, making it a more challenging choice from a building codes, cost and constructability point of view. But when evaluated in concert with structural and MEP systems, ETFE had clear advantages, especially given the cost premium of meeting California’s heightened seismic requirements. It’s three layers of foil with varied frit patterns maximize daylight while reducing solar heat gain, while its ultra-light weight – just one-tenth that of glass – greatly reduced dead loads on the supporting steel structure.
The modeling also included the building’s ongoing operation. ARTIC’s two high-transparency, glass curtain walls, soaring to 120 feet high at the North end, feature operable glass louvers controlled by a central building maintenance system to provide natural ventilation for the large atrium space.
A scalable approach. While critical for large-scale complex structures, the advantages of an integrated systems approach to facade design applies at all scales. For the Manhattan Beach Library designed by Johnson Favaro, collaboration across disciplines and structural glass analysis in ROBOT made possible an elegant, high-performance double glazed wall, completely transforming the symbolic presence of this new 20,000 sq ft public building.
While Europe has shown that higher performance standards can drive innovation in building technologies, we have proven that a holistic analysis that considers building systems, design and cost simultaneously can rationalize bolder measures regardless. So why wait?
Sanjeev Tankha leads the façades group for Buro Happold West Coast and was a key member of the design team for ARTIC. An architect who has specialized in facade design for nearly 20 years, he has led research and development of high-performance building envelopes for projects worldwide.
Now in his third and final term as mayor of New York City, Michael Bloomberg delivered what will be his last state of the city address to New Yorkers. The take away was to further green the city, with more recycling plans and similar such initiatives, but the big news was the mayor’s sweeping endorsement of electric cars, with plans to make taxis all electric and to add electric car charging parking spaces throughout the boroughs.
“We’ll work with the City Council to amend the Building Code so that up to 20 percent of all new public parking spaces in private developments will be wired and ready for electric vehicles, creating up to 10,000 parking spots for electric vehicles over the next seven years, said Bloomberg. The goal is aspirational and, if implemented as envisioned, New York City will have the most progressive programme in the country for electric vehicles.
Critics of the plan say it is too much too soon, pointing out that the plan assumes everyone will want an electric vehicle and be able to afford it. Also questioned is the long term future investment in electric cars, which is now in the nascent stage. Many electric vehicles can travel only 70 miles or so before needing to be charged. So unless major improvements are made on this end, the program most assuredly favours in town travel rather than long distance trips which, for many New Yorkers, is the main reason to keep a car in the city.
Naomi Wilcock, Editorial Assistant at World Architecture News
A new method of demolishing buildings by ‘shrinking’ them from the top down has been pioneered in Tokyo, Japan. Using technology developed by Tokyo-based contractor Taisei Corporation, the method is currently being used to demolish The Akasaka Grand Prince Hotel in Japan in a contract that will last until May 2013.
The process involves a jack-down system, with the roof section of the building gradually lowered while being supported by jacks and an internal crane moving debris and other materials down to the ground floor. “It’s kind of like having a disassembly factory on top of the building and putting a big hat there, and then the building shrinks,” Hideki Ichihara, a construction technology developer for Taisei Corporation, told Japan Times.
Demolishing the 139m-high hotel, which closed in March 2011, floor by floor, the change has been almost imperceptible to many residents nearby. Dispensing with the previous demolition method of using cranes and explosive materials, this process, known as the ‘Taisei Ecological Reproduction’ technique (Tecorep) is reported to be a safer, cleaner and more ecologically sound way of demolishing high-rise buildings.
Other advantages include the reduction in dust and noise production, as using the Tecorep method can reduce dust levels by up to 90 per cent through taking the existing structure apart from the inside. As well as this, the top-down process means the building can be demolished in all weather conditions and the reduction in disturbances to nearby residents means that, with their permission, work can carry on twenty four hours a day.
The second time this Tecorep demolition method has been used, it offers an environmentally-friendly way to raze skyscrapers in densely-populated areas such as Toyko with Taisei Corporation looking to sell the technology abroad in the future. First conceived as an idea in 2008, the technology was deemed to be necessary owing to the limitations of the crane in demolishing buildings of over 100m tall.
With Japan having almost 800 buildings standing at over 100m high and the average lifespan of a building of this size being 30 to 40 years according to Ichihara, Taisei Corporation saw a need to develop a new kind of technology. Japan currently has 104 buildings which are more than 20 years old, so the need for technological development in the area of demolition is seen as paramount.
Ichihara commented: “We thought, is it really possible to safely disassemble buildings over 100m? We thought we needed to research that, which is how Tecorep’s development started.”
The ecological credentials of the technology can also be seen in the energy-producing cranes used to move the debris, as the movement of the cranes creates enough energy to power lights and other equipment. As well as this top-down method, other demolition processes are also being looked at, including the top-up method called the ‘Kajima Cut and Take Down Method’ by Kajima Corporation, which demolishes buildings from the ground floor upwards.
William Poole-Wilson, Principal at Pringle Brandon Perkins+Will
Most people in the architecture and design industry will agree that sustainability is important. More than half of the world’s population live in urban areas and more than a million people move to cities across the world every single week. With this said, cities already use around 75% of the world’s energy and emit up to 80% of harmful greenhouse gases. Even climate change deniers (ever-dwindling in number) don’t deny that the earth’s natural resources are finite.
So if everyone wants to achieve the goal of better sustainability, why isn’t it easier to get there? It’s certainly not down to lack of incentive. We have carrots dangled before our eyes in the form of better public reputation and recognition, kudos among peers and stakeholders, and even the possibility of a speedier journey through the planning system , not to mention long-term financial benefits and the rather less tangible but extremely real opportunity to help preserve our planet. Meanwhile sticks are often brandished to force companies to comply with building regulations and compliance codes, while instituting penalties for low performance. Examples range from the Kyoto Protocol and the government’s 2020 carbon reduction targets to more elaborate schemes like the CRC Energy Efficiency Scheme.
There are three main reasons why we’re not progressing as quickly and smoothly as we hope: lack of communication, ignorance about the possibilities, and ignorance about the financial cost. I touched on communication in my previous post about Occupant Engagement and here I’d like to talk about a highly ambitious attempt to address the ignorance issue.
Through education we can achieve behavioural change, and behavioural change is a fundamental necessity in addressing not only sustainability issues at design and build but also in on-going operation. The most sustainable building in the world will fail to perform to expectation if it isn’t used as intended.
On 29th September, The Crystal opened to the public. Undertaken by Siemens with Pringle Brandon Perkins + Will as the lead consultant and interior architect, the awe-inspiring building is London’s newest landmark and the world’s first centre built with the sole purpose of developing urban sustainability knowledge.
Following £30 million in investment by Siemens, the 6,300 sq m facility is now home to Siemens’s global Center of Competence Cities, a team of multidisciplinary urban experts encouraging improved sustainability through research, partnerships and collaboration.
Standing proudly on the waterfront of Royal Victoria Docks in East London – the centre of London’s new Green Enterprise District – the Crystal is also the world’s largest exhibition space given over to the future of cities. There are 2,000 sq m of interactive learning covering building technologies, air quality, power and water supply, waste, healthcare and sustainable mobility.
It’s also a conference centre with a cinema screen and 270-seater raked auditorium. It is, in short, a huge think tank for a brighter, safer, more sustainable future. You can even recharge electric vehicles here too.
And a building to educate the world on sustainability needs to shine a beacon of fossil-fuel-free light itself. Originally intended to reach BREEAM Excellent, it became the world’s first building to attain both BREEAM Outstanding and LEED Platinum ratings over the course of the project.
Generating 20% of the building’s electricity, two thirds of the roof is covered in PV panels; the remainder is a green roof consisting of plant species proven to sustain local wildlife. Ground-source heat pumps supply 100% of the building’s heating needs and most of its cooling. Eighty-four percent of hot water is enabled through the PV and heat pumps. No fossil fuels are burned here at all.
The Crystal is also ready to be connected to the smart grid, and the BMS is central to all building operations (heating, cooling and ventilation; lights and blinds; sensors that detect occupancy levels; safety features; and even an outdoor weather station), collating data from 12,000 control points.
Not a drop of water is lost throughout the building. Rainwater is harvested and recycled or reused – 90% of potable water demand is technically possible through treated rainwater alone. One hundred percent of blackwater is treated and reused for irrigation and flushing lavatories. Of course, there’s a dedicated waste recycling area too.
The Crystal’s office space is designed to use on average 83kWh/m2/year (less than 50% of the energy use of comparable office buildings) and generate 65% lower carbon emissions too. And all this created on a tight schedule in a waterfront city location.
Buildings like this show what is possible – and can encourage us to think more sustainably across everything we do.
Peter Syrett, Senior Urban Designer/Sustainable Advisory Services Leader at Perkins+Will
In 1977 Ray and Charles Eames made a short documentary called the ‘Powers of Ten‘. The Eames documentary shows how perceptions of our surroundings change at different scales. The film starts by looking at a couple having a picnic in Chicago and zooms out in steps. Each step is a factor of ten. In 40 steps they take us out into space millions of light years away and back down to one angstrom – the size of an atom. The film eloquently shows us that the vastness of outer space also exists at the atomic level.
I have been thinking a lot about this film lately and how it can be a tool to illustrate how a simple act like turning on a light has a multitude of environmental impacts at an exponential range of scales – or how a light’s components, the electricity it uses, and the disposal of its lamps all contribute to larger environmental problems.
If we follow the Eames narrative, we should start with me sitting down at my desk to write this blog. I turn on my desk lamp and then start tapping away on my keyboard.
10+01: Extraction Economy
If we zoom out to an area of 10 meters, we will see that I’m sitting in a large open office with a desk light next to me. That desk lamp is made from a myriad of different metals and plastics. The plastics and metals in my lamp are part of 3 billion tons used annually for manufacturing building products and furniture. According to a 2010 Living Planet Report, at the current rate of comsumption, by 2050 we will be using 2.3 times the available resources on earth.
10+02: Energy Hogs
Even further out to the building scale of 100 meters, we will see my office just off Union Square in New York City. Even though this building is a LEED CI Gold-certified space, a city-wide energy benchmarking tool shows that 64% of the energy used here is to power computers and lights and that the building consumes much more energy than many of its neighbors.
10+03: Toxic waste
Now at 1,000 meters, we see my work neighborhood and the frantic traffic of lower Manhattan. Amid the cars are garbage trucks hauling away some of the estimated 600 million fluorescent bulbs that are thrown away each year in the U.S. The disposal of these bulbs, like the one used in my lamp, results in the release of 30,000 pounds of mercury, which is a persistent bio-accumulative toxin.
10+04: Air Pollution
Then at 10,000 meters, we are shown the whole of New York City. My desk lamp is powered by one of NYC’s power plants that is on average more than 30 years old. These plants aren’t as efficient as newer ones and use up to 60% more fuel and produce more pollution.
10+06: Climate Change
Finally, zooming out two more steps to a million meters, we can now see as far west as the drought-stricken farm fields of Indiana. A new study, according to the Union of Concerned Scientists, suggests that climate change may permanently create El Niño-like conditions in the Pacific basin, and the number and severity of droughts may also increase as a result. In other words, turning on my desk light, because it results in Greenhouse gas emissions, is in a very small contribution to the drought afflicting more than half of the continental U.S. this summer.
10-09: Body Burden
Then the camera would zoom in back all the way to me at my desk and continue zooming in to my arm and then through my skin down to 10-09 meters. At this scale, the made-man substances that I’ve absorbed into my body though ingestion, breathing, and touch can be seen. On my arm, we’ll soon find a molecule of Bisphenol A (BPA) floating around. BPA is absorbed in our bodies through touch and according to a recent study, is found in 91% of Americans’ urine. BPA is an estrogen-mimicking chemical that has been linked to obesity and to developmental effects to the brain, thyroid, and behavioral problems. It is used as a liner for metal cans in thermal paper and for more than 40 years as a hardener and an antioxidant in plastics. It is a key ingredient in epoxy resins, polycarbonate plastics, and other plastics such as polyvinyl chloride (PVC – a.k.a. vinyl). The desk light that I just turned on has polycarbonate lens and PVC wire jacketing, both of which are made with BPA.
All said, these different scales and more importantly the issues associated with them don’t exist in isolation. For us to succeed in solving problems like global warming, we’ll need system-based solutions that work on a molecular scale upwards. The impact of turning on a single fixture may seem minor, but the collective effect of 8 billion people turning on lights is significant. The Eames’s examination of the potency of scale shows us that everything is connected and that our actions matter.
In 1879 Edison forever changed our world when he invented the light bulb; if Edison were alive today, what would he be working on? I would like to think he would be hard at work on a desk light that did no environmental harm, regardless of the scale at which it was considered.
William Poole-Wilson, of Pringle Brandon Perkins+Will
Architects and designers are very good at designing high-performance buildings that save water and energy, reduce waste, improve air quality and increase occupant health and productivity. They take a holistic approach to building design that considers all aspects of the built environment as part of one system. But do we really understand the behaviour of those that use them?
Despite the despair at RIO 20+, the United Nations Conference on Sustainable Development showed that we have been getting some things right, but it’s a slow process with a variety of protagonists. Here are some words of wisdom from one of them, Gro Harlem Brundtland, who established and chaired the Brundtland Commission in 1983, out of which came the most widely used definition of sustainable development.
“Obviously when you look back 25 years now, less than one would have expected has happened – that’s clear – but you can’t think you can turn the world round in 25 years.”
“There are ‘complex reasons’ why governments have been unable to take the vision further – including the power of corporations.”
“In our political system, corporations, businesses and people who have economic power influence political decision-makers – that’s a fact, and so it’s part of the analysis.”
So the challenge is how to achieve more in the urban environment in the next 25 years. What’s missing? It struck me that some of the despair surrounding RIO was similar to the debate around landlords, building managers and occupiers. The corporations, politicians and people simply don’t agree. The occupier says they can do nothing because of the landlord’s financial and physical ownership, the building manager can only operate the system if the other two agree. They all need to be part of the design analysis, part of the brief.
An integral part of the built environment system is the building occupant. Without the occupants’ support of a building’s high-performing attributes, even the most well-designed building can fail to measure up to its high-performance potential. Occupants are critical to being sustainable despite often being ignored because of the complexity in addressing human behaviour.
A successful occupant engagement programme in a commercial building will help create a building-wide culture of awareness in which tenant organisations, employees and other stakeholders feel empowered and accountable for their contribution to a high-performance building. It is interesting that whilst RIO20+ was being reported, I was introduced to the work at the Toronto-Dominion Centre, by Perkins+Will.
Buildings have life spans and need to be maintained and retrofitted to extend the lifecycle of equipment and parts. The Toronto-Dominion Centre is not like any other building though. The landlord wanted to keep the tenants and run a better building. What’s unusual is that, rather than trying to introduce green leases or make other demands that usually create conflict, a facilitator who is knowledgeable about behavioural use of buildings has been introduced. In this instance, Perkins+Will, as the facilitator, gathered a brief and helped make change happen, bringing the players together to understand each other’s issues and grievances so they can be translated into opportunities. The TDC has set up a green council made up of tenant representatives appointed by their organisations’ executive leadership. The Green Council acts as the advisory group for developing and driving the engagement program, holistically linking and acting as the catalyst for sustainability.
A comprehensive occupier engagement programme, introduced by the landlord, will feed into this process. What is particularly interesting and refreshing about this project is that it didn’t start with assumptions, it started with behavioural change. The landlord engaged with its occupants and went beyond posters and emails, a template of tools, one size-fits all, capital investment, retrofit, or money saving measures to understand the behaviours of the users so the solution works for everyone. It recognised that every business is different and even parts of the same business operate differently with varying priorities.
The end result is a better building, thanks to a considered brief informed by a comprehensive understanding of the building’s design, its operations and use and its demographics. New elements incorporated into the building are there for a reason and as such are a good investment.
Because occupant engagement is a new and emerging practice in the commercial building sector, there are myths to dispel, myths that were all too clear at RIO20+, just as they exist in our own understanding of architecture and design right now.
Architecture can and should be inspirational and we must engage occupiers in a comprehensive and meaningful dialogue so we can effect positive change for the benefit of future generations.
William F. Baker, PE, SE, FASCE, FIStrucE, NAE; CTBUH Trustee and Partner at SOM
Next month, design industry leaders will gather in Shanghai for the Council on Tall Buildings and Urban Habitat’s (CTBUH) 2012 Congress. Titled ‘Asia Ascending: Age of the Skyscraper City’, the congress appropriately focuses on Asia’s ascent as a global center point for the vertical movement and the rapid urbanization of cities. And yet, while the continent is home to 85% of the world’s 20 tallest buildings and over half the world’s population, its significance extends beyond height and density. Asia is at the confluence of unprecedented growth and limited natural resources and it will serve as the benchmark for our 21st century professional response to sustainability concerns. As designers, this situation presents a defining opportunity that will forever impact the healthy future of our cities and all who inhabit them.
In recent years, the profession has mainly focused on the individual tower as a vehicle for sustainability. Designers employ multiple strategies, including advanced building control systems, climatically responsive layouts, advanced cladding systems, renewable energy sources, waste reduction principles and natural daylighting, in an effort to substantially reduce energy and water consumption, carbon emissions and waste. The next generation of high performance towers aims to provide a superior environment for building occupants while also minimizing the structure’s environmental impact.
And yet, while all of these efforts should be applauded, recent research shows that the most comprehensive sustainability approach begins with urban planning. Today’s city designers advocate for a more holistic vision of the urban environment, arguing that by merely focusing on the skyscrapers themselves, strategists are in effect unable to see the forest through the trees. Plans like Chicago Lakeside, Shunde New City and Beijing Bohai Innovation City demonstrate how environmental infrastructure can successfully weave with urban development. The award-winning plan for the expansion of Beijing’s Central Business District East Expansion not only proposes a network of enhanced transportation and pedestrian-friendly spaces; it also defines new strategies for building municipal infrastructure and high performance buildings. If implemented, the plan could reduce energy consumption within the district by 50%, water consumption by 48%, landfill waste by 80% and result in a 50% reduction in carbon emissions. The reduction in office building emissions alone is equivocal to planting 14 million adult trees.
The sustainability challenge is better addressed as the sum of its many parts. A holistic strategy is necessary to ensure the growth of our global cities and the health and ecology of our communities. While the CTBUH has long been the leading body in the field of tall buildings, it will be interesting to see how the organization embraces the burgeoning significance of the urban habitat, particularly as it relates to sustainability concerns. With 400 million people expected to migrate to Chinese cities by 2050, rapid urbanization and our sustainable response is a timely matter and one which will undoubtedly merit worthy discussion at the upcoming congress.
Peter Irwin, Senior Executive Consultant & Past President, Rowan Williams Davies & Irwin Inc., Council on Tall Buildings and Urban habitat, Board of Trustees
The unprecedented wave of exceptionally tall buildings being designed and constructed around the world is only one of the most eye-catching manifestations of the rapid urbanization of mankind. Architects, designers and urban planners are increasingly aware of the need to build more sustainable buildings and infrastructure. But there is a need to give equal knowledge-based attention to creating and preserving an ecologically sustainable natural environment within our urban areas.
Most architects and planners are aware that green spaces, parks and woodlands are essential elements of the urban habitat and that they contribute greatly to the livability of cities and to the health and well-being of citizens. Trees provide shade, help retain water and control run-off; flowering plants and shrubs beautify and attract wildlife such as birds and butterflies, and can provide shelter from winds. However, designers and landscapers often take a narrow view of what this means in practical terms.
Planting hardy and drought-resistant plants to minimize maintenance and reduce water usage is simply part of creating sustainable natural environments in urban areas. We need to green our cities in a way that fosters an ecologically diverse natural environment; one that supports the lifecycles of the insects, birds and other small mammals that are part of a healthy and sustainable eco-system. These creatures need food and water as well as nesting, roosting and overwintering sites – a habitat that for thousands of years has been provided by the plants growing naturally in the local area. Landscaping that emphasizes turf grass and a narrow range of non-native shrubs and flowering plants will not support viable eco-systems and will hasten the decline in the number of birds, butterflies and other beneficial insects, found in urban areas.
The urban habitat can actually help restore diversity if we plan it right, by including parks and landscaping features that are deliberately planted with species that cater to pollinators and other native insects. There are now many interesting examples of ways to create ecologically diverse and sustainable green infrastructure in urban areas: the High Line project in Manhattan, Ken Yeang’s bioclimatic skyscrapers and the proliferation of green roofs in a number of cities are just a few examples. The Royal York Hotel in Toronto uses its 13th floor roof terrace as a garden to grow fresh herbs, tomatoes and edible flowers for its kitchens and also has beehives to ensure pollination. In my hometown of Guelph, Ontario, Canada, a local charity, Pollination Guelph, is raising awareness of the need for pollinator-friendly gardening and landscaping by planting demonstration gardens in parks and domestic and commercial properties. They also plan to re-naturalize and create a pollinator meadow on a 45-hectare decommissioned landfill site. I suspect we are only at the beginning of exploiting the urban habitat’s capacity to provide both green and liveable spaces while supporting ecological diversity.
Note: This post is excerpted from an earlier column in the CTBUH Newsletter. The CTBUH will be hosting its 9th World Congress in Shanghai, 19-21 September ( www.ctbuh2012.com
Antony Wood, Executive Director, Council on Tall Buildings and Urban Habitat
The vertical city is increasingly seen as the most viable solution for creating more sustainable urban centers, especially in developing countries such as China or India where population growth and urbanization is at its most pronounced. However, the full implications of concentrating more people on smaller plots of land by building vertically need to be better researched and understood.
Image: Adrian Smith and Gordon Gill
On the one hand there are many energy benefits from building tall. Growing taller and denser versus horizontal spread offers distinct advantages for urban infrastructure systems. Efficiently-designed tall buildings utilize less materials for enclosure per unit of usable floor space, a smaller surface area for heat loss/gain, a natural energy share between floors and provide the potential for harvesting solar and wind energy at height.
On the other hand there are disadvantages with building tall that offset, and may even negate, the benefits of concentrating people together in taller buildings. Smaller floor areas may limit people’s access to natural light, views and ventilation. Growing taller requires more materials and primary structural systems, which may affect the overall sustainability equation. The general concept of ‘vertical’ being more sustainable than ‘horizontal’ may be true, especially when the larger-scale urban scenario is considered, but the myriad factors that contribute to this scenario should be better investigated.
During the CTBUH 9th World Congress in Shanghai, 19-21 September, the Council will formally release its latest technical guide, Natural Ventilation in High-Rise Office Buildings, part of a series of CTBUH publications that analyze various aspects of tall building performance. Heating, ventilation and air conditioning (HVAC) in tall buildings typically account for 33 percent or more of overall tall building energy consumption, according to U.S. Department of Energy data. More than half the HVAC energy use in a tall building is the result of efforts to reduce heat gain, lighting, miscellaneous power use, and systems to counter solar and thermal fluctuations. It could be argued that the increased efficiency – or elimination – of these systems is the most important single step in making tall buildings more sustainable.
This type of research is essential to the future of tall buildings and cities. Building owners, developers and consultants need to understand the ‘sustainability threshold’ for height – that height or floor count beyond which additional height would not make sense on sustainable grounds. This will never be an exact science and will differ not only from city to city, but from site to site and building to building. It is, however, a measure of extreme importance – and one which the global building industry needs to urgently strive toward.