July 2014

When Did Buildings Become “Green”?


Katherine Mortimer


Northern New Mexico is a green building leader and has actually been so for thousands of years. Ancient Anasazi Indian homes were shaded from the summer sun by building within an overhang of a cliff, under which the low winter sun would then reach, heating up the stone and mud exteriors, thereby storing energy in thermal mass to be released during the cold nights. The temperature of the rear of the dwellings would be kept fairly even due to the thermal properties of the earth of the cliff the homes were built into.

Cliff DwellingsPueblo Indian descendants of the Anasazi developed unique, stepped-design architecture and construction systems, which allowed a construction style similar to that of their ancestors but could be employed where there wasn’t an existing cliff. They used limestone blocks or large adobe bricks (about 8 x 16 x 4 inches), replicating the stone and mud walls of cliff dwellings. Rectangular rooms would be built on top of each other, over generations, in an irregular pyramid fashion, sometimes up to five stories high. The dense exterior walls would be warmed by the sun during the day and reradiate it out at night, as with their ancestral cliff dwellings, although the north side of these structures would be colder, not having a cliff to shield them.

European building materials and techniques were imported from the East, even though the building materials they call for, mostly wood, are in short supply here in New Mexico. This represented a less-green time for New Mexico buildings. These buildings were outfitted with furnaces, then evaporative (swamp) coolers and, eventually, air conditioners, using lots of then-abundant and cheap fuel and electricity. Then, in the 1970s, there was a resurgence in passive solar adobe construction, as well as a proliferation of other solar thermal-storage strategies. Many of these buildings have more glass than would be recommended today and were designed to be “leaky” to allow for natural ventilation.

While solar thermal panels have remained all but unchanged through that last half-century, photovoltaic (PV) panels have been steadily improving. However, 1970s’ solar-panel installations covered a much larger area than they do today to produce the same amount of electricity. In the 1970s, PV installations could cover the south-facing side of a house, even with the angle of the south wall tilted to maximize their efficiency.

Earthships took the energy self-sufficiency of passive and active solar systems and design to a new level. Starting in the Earth Ship1970s, as well, earthships have evolved to include self-sufficiency in all energy, water and food needs of the building and occupants and incorporate recycled and readily available building materials, reducing the “cradle-to-grave” impact of these dwellings. They are the penultimate example of green building, but their initial cost reduces their market even if they are all but free to live in.

Green building programs began emerging early in the 2000s, first focusing on commercial buildings and eventually on residential. Santa Fe was one of the first communities to develop a green building code. The current code affects only new, single-family residential buildings, but a code for residential additions and remodels will go into effect on Aug. 1, 2014, and a commercial code is being finalized. These programs and codes address the lot design, resource-, energy- and water efficiency, indoor air quality and building-owner education. They don’t look different from any other building and can therefore be incorporated into any community’s historic or aesthetic style.

Passive House, developed in Germany, is a standard to reduce the heating and cooling load of a building by 90 percent or more. These buildings are super-tight, with little natural ventilation from leaking, and super-insulated. They therefore require mechanical ventilation to maintain healthy indoor air quality. By adding a device that takes the energy of the indoor conditioned air and exchanges it with the unconditioned outdoor air, it reduces the energy loss from leakier homes. Because this standard does not rely on passive solar, buildings built to it look essentially like traditional wood homes. While meeting this standard has meant added costs, Santa Fe’s Habitat for Humanity is currently building a duplex using this standard as a guide, demonstrating how it can be done affordably.

Buildings don’t exist alone. They are located within communities where people have to go to work, school, shop, get services, recreate, etc. The next horizon is to address the context within which buildings exist. Higher density reduces the number of vehicle miles traveled within a community and increases walking and biking, which, in turn, promotes public health. However, people enjoy their privacy, solitude and quiet, which may seem contrary to higher densities at first. There are examples of higher-density developments that detract from the visual and social environment. At the same time, there are examples of ones that contribute to them. I would venture to guess that community design will be the next frontier in green building. Are we in northern New Mexico ready to be on the forefront of this new chapter in green building as well?


Katherine Mortimer is Sustainable Santa Fe programs manager for the city of Santa Fe. http://www.santafenm.gov/sustainable_Santa_fe




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