Introduction to Zero Energy Design Bio-Responsive Design
First a building must reside comfortably in its place. The bio-responsive building can be summed up in the words:
“The building should tell a story about place and people and be a pathway to understanding ourselves within nature.”
- Sim Van der Ryn
Throughout human history, man has built with reverence to sun, wind and light, maintaining a careful balance between mass and membrane. Since ancient times, builders have practiced the acquired art of building with mass, such as in an adobe wall, anticipating the intensity and direction of the sun’s rays. They knew how thick to construct walls in order to store the heat of the day for use during cold winter nights, and the right thickness necessary to cool the interior during the heat of summer. They understood the inherent “capacity” of the walls in terms of storage and thermal lags. And they worked with the resistance of materials to heat transfer in order to reduce heat loss in winter and heat gain in summer. They knew how deep overhangs needed to be to block the unwanted sun in the summer and yet allow its warmth to provide heat in winter. These were very sensible buildings for their climate.
The challenge has always been to combine openings to admit air and light with the appropriate amount of mass. Medieval buildings, particularly the cathedrals of the twelfth and thirteenth centuries, pushed the openness of the envelope to its structural limits in order to achieve light buildings (light in more ways than one.) This careful balancing act continued for the most part up until the modern era, which arrived with the advent of inexpensive glass and electric light. It was unfortunate that at the same time large sheets of glass and incandescent light bulbs became available, the era of cheap energy arrived also. And because of that, architects for nearly a century have no longer relied on the sun for heat or illumination. At best, they treated the sun and its energy as an afterthought.
Designing buildings today involves renewed attention to old practices and altered thinking about how our human comfort can be attained without encumbering ecological damage and needlessly wasting energy and resources. The present imperative to design Zero Energy, carbon neutral buildings requires not only designing for thermal comfort but also designing for human health and human survival.
The Zero Energy Design imperative is to consider relationships between climate, sun and wind, with building form, mass and skin and then to design compact, robust mechanical systems, and employ successful integration of passive and active solar and renewable energy systems resulting in net zero energy consumption for the year. This should all be achieved within the context of defining and addressing rigorous sustainable goals.