[Sustainable DNA] involves a return to designing with those considerations and conditions that informed architecture and construction for thousands of years before the Industrial Revolution while maintaining the most useful and efficient aspects of modern technology and invention. The following are the 4 principles of [Sustainable DNA]. Like the 4 bases that comprise the human genetic code, these 4 principles are interrelated. They can not be successfully implemented individually. They can also be grouped in pairs like the AT and CG pairings that create human DNA. Solar Orientation and Natural Ventilation are closely related as they help determine the form, shape and arrangement of a building. The second pair consists of Material Economy and Local Sourcing. These influence the material characteristics and size of a building.

While these principles are generally applicable to any place, they must be tailored and weighted to suit the specific location of the building. I will describe them using conditions particular to southern California. This region enjoys a warm, semi-arid climate. While not subject to the annual freeze and thaw cycle prevent in much of the United States, southern California is given to a wet season (two closely spaced ones, actually) when heavy rains are common. The coastal areas of southern California are typically cool, kept that way for most of the year by high-altitude coastal fog called the marine layer. The coastal plain warms in the late summer and early fall when a hot off-shore flow of air predominates. Southern California’s inland valleys are often 20° to 30° warmer than the coastal plain in the summer and fall. This is due primarily to mountain ranges that shield these areas from the moderating effects of on-shore ocean breezes and marine layer.

[A] Solar Orientation There are times, during the cool winter months, for example, when the heat derived from the sun is desirable in the interior of a building. Orienting a building’s most frequently inhabited areas toward the south allows occupants to benefit from natural warmth and light. The precise location of fenestration, and the architectural features around it, should be designed to limit the amount of direct natural light received during the warmer summer and fall months, however. Similarly, the late afternoon and early evening sun is particularly intrusive in the summer and fall. Its position in the western sky should be taken into consideration. This is where insulated glass and external shading devices can be employed to limit heat gain while maintaining natural light and exterior views. Exterior views in this direction are frequently important in southern California since the ocean is always to the west.

When exterior materials are being selected, understanding how different material absorb or reflect heat is important as well. Cement stucco is ubiquitous the region. This is largely due to the fact that southern California never possessed the extensive and dense forests that are (or were) so common in other parts of the country. Cementitious materials, especially when applied in any thickness, tend to store heat from the sun. This heat then radiates out as the ambient air temperature drops in the evening. In older buildings without insulated wall cavities, this heat will find its way into a building’s interior, causing a structure to warm up as the temperature drops outside. Therefore if stucco has to be used on the southern and western facades of a building, it is important that it be applied over well-insulated walls. It can also be painted in a light color to reflect some of the sun’s energy or shading devices can be employed on a seasonal basis.

[T] Natural Ventilation Southern California is not prone to the humid conditions that predominate on the east coast of the United States. Therefore, shade is most often cool, as there is little moisture in the air to transmit the heat from the sun. The predominant flow of air is from west to east. Natural ventilation is a passive cooling method that affords a comfortable interior environment without the constant need for mechanical equipment. Whenever possible, buildings should be narrow when measured from east to west. This allows air to pass easily through the interior without having to traverse a warren of separate spaces that would inhibit its flow. When this building shape is not possible due to the size and configuration of the site or the building’s program, interior spaces that run the length of the building, such as hallways, are useful for encouraging air flow without mechanical assistance.

Natural ventilation can also be implemented vertically in a structure. We are all aware of the fact that warm air tends to rise in relation to cooler air. As warm air particles rise, cooler ones are drawn into the place of the warmer ones. A building with strategically placed vertical shafts and/or openings between floors can take advantage of this phenomenon and thereby reduce its reliance on mechanical cooling and ventilation. These devices are commonly referred to as heat chimneys and can actually create air flow through natural convection currents even when an external breeze or wind is not present.

[C] Material Economy Sustainable buildings consider the efficient use of materials as well as space. In addition to the energy they consume, all buildings represent a certain amount of embodied energy. Embodied energy is the energy that was required, not just to construct the building, but to grow, harvest, refine, manufacture and/or transport all of the materials in the building. It follows then, that a building that uses less material per square foot of area will be a more economical structure. It also true that a smaller building will use and embody less energy.

This position can be a tough sell, particularly in a society whose economy and culture are driven by consumption. Economic growth is most often directly related to increases in consumption. In fact, the average house built in America today is nearly 50% larger than one built at the end of World War II; this despite the fact the average family size has decreased. While the Great Recession is forcing consumers to rethink their habits and make adjustments (voluntary or otherwise), there is a strong argument to be made that the quality of our built environment is more important than its gross quantity–regardless of the state of our economy. Efficiency and quality can and should replace size and bulk as most important values in our buildingscape. A more spatially efficient building that is of higher quality may contain the same amount of embodied energy as a larger building. But because it is of higher quality, that building will last longer and its embodied energy cost amortized over more time, making it more efficient.

[G] Local Sourcing This principle could be considered an aspect of Material Economy, but in the context of global capitalism, it is worth discussing on its own. The following example illustrates the importance of locally sourced materials:

While it may be fashionable to have bamboo floors in one’s home, this may not always be the most sustainable option. Indeed, bamboo is lightweight, strong and is a rapidly renewable resource. Most of it however, is grown far from the United States and then transported by ship to American markets. Consequently, the energy this material embodies can be relatively high. The fact that using bamboo does not require the harvesting of hardwood from forests in the western hemisphere is important, but may be outweighed by its relatively remote location. Alternately, flooring that has been locally reclaimed from an old building and refinished is more efficient and sustainable because the energy embodied in the material is being reused along with the material itself.

In addition to this, locally sourced materials are typically those that are naturally compatible with local ecological and climatic conditions. They are therefore more durable, require less maintenance, and over time, use less energy.

The application of [Sustainable DNA] principles will result in buildings that are more economical to build, are more energy-efficient and are healthier to occupy than traditional structures. In addition to these practical benefits, buildings designed with [Sustainable DNA] afford us the opportunity to create more meaningful connections with the places we inhabit and offer us more articulate experiences of to the time and space we call our own. These same principles can also be expanded and employed in urban and regional planning. In fact, a sustainable building is of limited value if it does not exist in a broader sustainable schema.

Architecture is not technology, except to say that architecture employs technology as a means.

Architecture is a cultural practice that results in the construction of a building. As such, architecture is concerned primarily with dwelling. Here, “dwelling” does not refer to residential building. Rather, dwelling is a condition of being. To paraphrase Martin Heidegger, we dwell on the Earth and under the sky.

We give form to our existence through architecture.