Ken Yeang is an architect and was an early theorist of green architecture. In England, where he was educated at the AA (completing a diploma under Peter Cook) and Cambridge where he earned a PhD in ecological planning and design, Yeang is celebrated as a founder of the sustainable architecture movement. In 1995 he published his major theoretical work Designing with Nature that evolved out his Cambridge thesis and it is one of the first texts on ecological architecture. At the The Architect’s Newspaper’s Facades+PERFORMANCE conference on July 11, Yeang will lecture in the US for the first time at the University of California San Francisco in Mission Bay. Yeang recently answered a series of questions posed by Mic Patterson of Enclos who will introduce him in San Francisco. Here is part one of the interview, the second half will appear tomorrow on the AN Blog.
Mic Patterson Your early theoretical work, and ultimately your built work, anticipated the sustainable development that is finally beginning to emerge at a broader scale: climatic design, green walls and vertical gardens, sky courts, biomimicry, solar geometry as a form generator. Why has the adoption of these concepts by the building community been so slow? How do you see these themes developing into the future?
Ken Yeang. I am not sure why our concepts and ideas on green design have been slow to gain traction by the building industry and by our community of professionals. It may be because public adoption of new ideas first require champions by important figures like politicians and leaders in the profession and industry.
(Courtesy Ken Yeang)
I started work in this field in 1971—it was the topic of my PhD dissertation at Cambridge. It took a while for leading politicians and professionals and others in the building industry to champion sustainable design, probably around the late 1990’s. Sustainable issues are essentially ethical issues and because these do not have immediate commercial impacts, often no action is taken until a disaster brings them to the forefront.
With regard to how I see these themes developing in the future, my view is that green design is still in its infancy. There is there is still so much more to be done and this will continue to progress in the future. There is much more theoretical, technical and design interpretation work to be accomplished. For instance with bioclimatic design, there are many bioclimatic systems for different climatic zones that need to be developed and tested (e.g. evaporative cooling systems at non-commonly adopted climatic zones, work to advance the technology of the Trombe walls, low-energy flue-wall or flue-atrium type of natural ventilation systems, climate-responsive facades responding to different seasons of the year and at different climatic zones, etc.)
With green walls, many of the current systems are essentially hydroponic systems. We need self-sustaining green wall systems that are not hydroponic, and green wall systems that enable a greater range of native species to be used. With vertical gardens, we need advancement of systems of vertical integration. We need to find ways to bring daylight to the vegetation at the inner depths of vertical gardens. Finally we need to design vertical gardens that can survive through all seasons of the year especially in cold and temperate climates, and devices to enable them to withstand high wind speeds at the upper parts of buildings, etc.
Further studies need to be done on skycourt typologies, further studies on how these can be better integrated with vertical landscaping and sky-parks while maintaining an ecological nexus with the landscape at the ground plane. We also need studies on how these as public ‘places-in-the-sky’ can be beneficial and integral with the social lives of high–rise inhabitants, etc. “Biomimicry” is of less interest to me whereas I regard “ecomimicry,” where design imitates the properties and attributes of ecosystems to be more relevant to green design. I did research work on biomimicry in 1972 when I wrote a number of papers (published in AD and in AAQ [Architectural Association Quarterly] on ‘bionics’ and on the use of biological analogies for design. These led me to conclude that for ecological design, ecomimicry is more directly relevant to green design than biomimicry.
While LEED has encouraged and enabled many professionals to be involved with green design and had been immensely successful in proselytizing green design to a wide public audience, it is an incomplete system and not environmentally comprehensive. What differentiates our work from other green architects is its authentic ecological basis for design. This is more relevant as it is fundamentally premised on ecology and environmental biology. We see this as the focus of the next generation of green design.(Courtesy Ken Yeang)
MP: The bioclimatic skyscraper is a compelling notion for a sustainable tall building, yet many feel that, while tall buildings may facilitate density, they are a fundamentally unsustainable building type. Do you feel, for example, that net-zero operational energy performance of a tall building is practically achievable on a widespread basis?
KY: It is necessary to appreciate that “bioclimatic design’”is essentially “passive-mode low energy design” and “mixed-mode low energy design.” “Passive-mode low energy design” is designing (eg. built form configuration, facade design for solar protection, use of bioclimatic devices,etc.) to respond to the climatic conditions of the site while optimizing the ambient energies of the locality to result in a built form that is passively low energy without the use of any mechanical and electrical systems.
Whereas “mixed-mode low energy design” is designing in relation to the climate of the site optimizing the ambient energies of the locality to result in a built form that has a partial use of M&E systems.
Bioclimatic design is only the first step in ecological design. It is a subset of ecological design, and provides the basic armature for ecodesign, following which other aspects of ecological design can be incorporated holistically with the built form. In this regard, the ‘bioclimatic skyscraper’ is not a sustainable design per se but only a partially sustainable design, where other aspects of sustainable design (e.g. water management, carbon neutrality, biodiversity, etc.) need to be subsequently taken into account.
Yes, most tall buildings are fundamentally unsustainable buildings unless located over transportation hubs. This is because the tall building utilizes around 30% or more energy, materials and engineering systems to build, operate, reuse, recycle and to demolish. We should not build tall unless we have to. My rationale for looking into this building type is that the tall building type is a builtform that will not go away overnight. It exists for many prevailing urban and land economic reasons.
If this built form shall be with us for a while, my contention is that we should not negate them but on the contrary seek to find ways to make them more humane to inhabit and find ways to make them as green as possible. If all the green designers of the world negate this built form, then who will make them as green or pleasurable to inhabit as possible? The net-zero operational energy performance of a tall building can in principle be practically achievable but it will be dependent upon the level of internal comfort conditions acceptable to dwellers.
MP: Do your theories of eco-architecture and bioclimatic design translate easily to climatic zones outside of the tropics? What would a bioclimatic skyscraper look like in San Francisco?
KY: What an odd question? Certainly the theories of eco-architecture and bioclimatic design are generic and are applicable to all climatic zones—not just in the tropics. However we must be clear that ecoarchitecture and bioclimatic solutions are site specific. What is effective for one locality and for that latitude, climate conditions and local ecology cannot be applicable to other latitudes, other climatic conditions and other local ecological conditions.
Nevertheless, the principles (being generic) of ecoarchitecture and the principles of bioclimatic (as a building science basis for architectural design) remain applicable to any climatic and ecological locality of the planet. What will differ are the design responses to the different climatic conditions.
However the design interpretation and application of these principles for each location (latitude and climatic conditions) will be different.
To your question, “What would a bioclimatic skyscraper look like in San Francisco?,” the answer is that it will look totally different from a bioclimatic skyscraper in the tropics. Most likely a bioclimatic skyscraper in San Francisco will have a variable facade that will enable it to be operable for different seasons of the year. Likely we can make us of the “natural buoyancy” in the San Francisco climate in the mid season spring and autumn) as a “flue façade wall” or “flue atrium” for natural ventilation to create a low energy built form or atrium. These can create a totally different aesthetic for a San Francisco bioclimatic skyscraper than a bioclimatic skyscraper in the tropics.
MP: Are there emerging building materials or technology that your are excited about, the hold the potential to facilitate the transformation of the built environment toward a sustainable future?
KY: Yes, there are many emerging building materials or technologies that are exciting that hold great potential to facilitate the transformation of the built environment toward a sustainable future—such as the use of nanotechnologies in materials and facade coatings, in future PV cells that imitate photosynthesis, in use of “cloud computing” in building automation systems, in climate responsive façade systems, in low energy carbon neutral environmental systems, etc.