A professor and longtime proponent of Sustainable Architecture reflects on the harmony of the Bhutanese building traditions following his visit to Bhutan.
Traditional Bhutanese architecture is green, energy-efficient and aesthetically pleasing. The celebration and promotion of traditional building practices in the kingdom offers the western student of design the best present day lessons in architectural integration.
By integration I refer to the exquisite connectedness possible between ecological setting, culture, settlement pattern, architecture and art. In Bhutan this connectedness exists throughout the spectrum of the vernacular to the monumental, the secular to the sacred, more so than in any present architectural tradition.
Whether a farmhouse or a Dzong, the same architectural form, expression of materials, aesthetic compositions and incorporation of the arts exist together in a synergetic way. Synergy in architecture is where the whole becomes greater than the sum of the parts and the parts become optimized because of their relationships to the whole.
Our guests help at saa-chaam (lit. "earth-pounding") which, like a traditional western barn-raising, is a communal event in Bhutan
For those of us from countries where there is a tradition of contrast between the vernacular and monumental and secular and sacred buildings it is important to experience a tradition where these aspects are so integrated. Even more important, due to the industrialization in much of the world different architectural concerns like these have become fragmented in modern architecture. Therefore it is extraordinarily valuable to visit Bhutan and to be able to experience this degree of architectural integration, to be able to see the resulting aesthetic quality and vitality that is possible within this whole spectrum of architectural endeavor.
The grand courtyards of the Thimphu Dzong are wonderful examples of form meeting function in traditional Bhutanese architecture
A specific comparison of some changes required to develop more green architecture in both the USA and Bhutan will point out the differences in our prospective situations and to how we can learn from each other. Both countries have valuable contributions to make. One specific part of green design that integrates the energy, health, and material components of green architecture is passive building design. Passive design is where as much as possible of the metabolism of the building (heating, cooling, ventilation, lighting, and electricity production) is provided by the design and the materials used for construction of the building.
This can be accomplished by envisioning the building as a holistic system that creatively responses to the microclimate of the site, using natural energy sources and sinks on the site to perform these functions. This is in contrast to modern industrial architecture where buildings are seen as receptacles for mechanical and electrical equipment, which performs these functions using energy imported to the site. Passive buildings must creatively respond to solar radiation using it to heat when needed and protecting itself when cooling is needed. This means that orientation of the building to solar geometry is of primary importance. In temperate zones like the US and Bhutan this means facing the building toward the equator (south in the northern hemisphere).
Passive buildings must be able to store the relatively diffuse on-site energies it uses so they must be well insulated and have enough thermal mass to prevent inside temperature swings outside the comfort zone. Insulation and thermal mass are often confused as the same thing. They are not.
Insulation prevents the flow of heat. Thermal mass moderates the interior temperature swings. Insulation needs to occur on the outside skin of the building while thermal mass is most effective inside the building. Thus its better to have heavy interior walls and light highly insulated outside walls and roofs.Passive buildings must be able to breathe using natural ventilation to provide healthy interiors and cooling when needed. Passive buildings should produce their own electricity via the integral use of photovoltaic materials to provide for backup lighting and other needs.
Recent advances in photovoltaic technology mean this material can be integral to the skin, or windows, or shading devices on passive buildings. The present state-of-the-art of passive design is such that we can, by using on-site energies with the appropriate construction materials, provide very high percentage of the energy needs of the building even to the point of creating zero-energy buildings. There are zero-energy buildings being built and operated at this time in many places in the world.
Built entirely from locally sourced materials and without using a single nail, Bhutanese farmhouses are often allowed to disintegrate back into the earth at the end of their lives. © Bhutan Himalaya Expeditions.
To illustrate the importance of this ability it is helpful to look at the magnitude of the effort that humankind must expend over the next 50 years just to stabilize our climate. One such study done at Princeton University in the US shows how much reduction of carbon dioxide emissions into the atmosphere must be made for the next 50 years just to maintain our present situation in regard to global warming. This study then breaks this formidable amount into seven segments or wedges and calculates the actions it would take to accomplish each of these. It is very interesting to compare the efforts we can take to the wedge reduction we can accomplish. Stopping all deforestation would give us one wedge. Bhutan is probably one of the few nations in the world that is doing this at the present time. Doubling the fuel efficiency of every automobile in the world would give us another wedge. Making all buildings worldwide high performance passive buildings gives us two wedges!
Putting photovoltaic panels on all buildings worldwide gives us another wedge. From this we can see that by using present day passive design principles we can get three out of the seven wedges needed. Pushing the envelope a little further by creating a high percentage of zero-energy buildings would allow us to get the majority of the wedges needed to stabilize our climate. Now let us look at the situation in the U.S. in this regard. Although much of the scientific analysis that allows optimization of passive buildings was developed in the US in the 1980s the tradition of the scientific method has ironically impeded the application of these principles. Our society is so conditioned to look at parts first that we have a very difficult time collectively imagining a building as a holistic system. Architects and builders have had problems getting away from the dominance of pieces, especially mechanical pieces.
For example in Central California, which for so much of the year has a very benign climate, we are still building buildings that are closed boxes with poorly oriented windows that cannot be opened, with all lighting, day and night, provided by way of electrical fluorescent lighting. These buildings are not very pleasant environments, are very expensive to operate and are generally unhealthy. These conceptual barriers mean that even twenty years after the development of the science of passive buildings and the development and testing of the analytical models that allow their optimization still only a small percentage of the buildings being built are passive.
Now let us compare the situation in the U.S. with the situation in Bhutan. The kingdom has several advantages with regard to passive building application. There is still a living architectural tradition of building with high mass materials so the concept of thermal mass should not be so foreign. Natural materials from close proximity to the site, the recent use of concrete not withstanding, is also still traditional so life cycle design is easier to put into place. Like the US, south orientation is not generally the rule but there are good examples of optimum orientation in some very influential buildings such as the Kurjey Monastery in Bumthang.
What is needed is better glazing, which will come with more development, and better insulation to be used in conjunction with the existing high thermal mass materials. Perhaps material presently disposed of in agricultural burning can [instead] be used to provide insulation on the exterior of the traditional rammed earth walls, which can then be plastered with mud or stucco as in the [case of] straw bale construction in the US. This would use some cement but far less than the standard concrete construction. I am convinced the best advantage Bhutan has is the emphasis on interconnectedness that is such an outstanding feature of Bhutanese architecture.
This longstanding tradition of appropriate cultural and environmental considerations in building practices in Bhutan should make it much more easier to conceptualize buildings as integrated systems than here in the United States.
The present human condition is fraught with great problems but also great opportunities. In order to minimize the problems and enhance the opportunities we all need to learn from one another.
The technological and analytical basis of green architecture can be learned from the US while the power of interconnectedness and synergy can be learned from Bhutan.
It will take the best of both worlds to develop and apply green architecture on a scale appropriate to the problems and opportunities we all face as co-inhabitants of our increasingly fragile planet.
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Ken Haggard is a leader of the green building movement and a principal designer of San Luis Sustainability Group. He works and writes from an office that is housed in a zero-energy building that utilizes a micro hydropower scheme, photovoltaic cells and passive-solar construction.