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Making your home energy efficient

More imaginative people build homes with blue jeans as insulation or use stacked recycled carpet tiles for the exterior walls

Making your home more energy efficient is one of the more common ways of saving money and conserving the environment. More imaginative people build homes with blue jeans as insulation or use stacked recycled carpet tiles for the exterior walls. Old airline wing flaps can serve as greenhouse roofing. These homes are not old hippie shacks. They are architecturally sophisticated structures that utilize some of the best elements of sustainable design.

The term "sustainable design" has been bandied about for years. It covers a broad spectrum of philosophies, but its goals remain constant--to conserve the environment and to enhance the health and well-being of those who live there.

Two new design books show just how far we have come in sustainable home construction. New Sustainable Homes: Designs for Healthy Living by James Grayson Trulove and Sustainable Environments by Yenna Chan feature original designs of the best in sustainable living.

Once the territory of left-wing eccentrics, sustainable architecture is now the fastest growing segment of the industry. Trulove notes that sustainability is almost a given in custom homes right now. "Even tract houses are using sustainability," he says.

Green interiors have carefully considered rugs and wallpaper, and appliances have become increasingly energy-efficient. Trulove says that all of these components contribute to the resale value of the home in an ever increasingly conscious market.

The reasons for this phenomenon are both practical and environmental. The home is healthier to live in and materials that are recycled can have a positive effect on the environment. Utility costs can be greatly reduced depending how energy-efficient the home is.

According to Trulove, constructing an environmentally sound house should not cost more than building the traditional way. "I would advise anyone to sit down with an architect and look at the materials and do a cost comparison," he says. "Many would say that even if it costs more initially, over time you would recover in energy costs, and the resale value is higher."

So what constitutes a green or sustainable home? Trulove says that you can make a green statement simply by redoing an existing structure.  "Many people today are buying homes where the lot is worth more than the house. Building an addition utilizes less energy and materials than constructing a new house," he says.

New Sustainable Homes features an array of homes around the world that boast unique sustainable attributes.

One stunning residence in Los Angeles was built entirely of recycled storage containers, grain trailers, steel, wood joists and glass. The grain trailers were transformed into a lap pool and koi fish pond. The end result is an ultra-modern, open and high sculptural home surrounded by native plants.

Another home featured in the book is a 2,350-square-foot slab-on-grade house that sits on 21 acres in rural Virginia. The hallways are four feet wide, and there is a 5-foot turning radius in a corner of the kitchen. There are pocket doors, drawers and shelves in the kitchen instead of cabinets. This simple yet elegant design was built to maximize passive solar gain for energy. The wood came from nearby trees. The exterior insulation is bio-based soy foam, and the inside insulation was made from recycled denim from old blue jeans for sound attenuation.

In Venice, California, a solar umbrella addition changed a 650-square-foot bungalow into a 1,900-square-foot solar-powered house.

The solar skin absorbs the sunlight rather than deflecting it, transforming the light into usable energy--so usable that it provides 95 percent of the home's electric load through the 89 silicon solar panels.

There are no immaculate lawns featured with these houses. Native plants and natural scenery form the backdrop to the structure weaving nature in and out of the space. Landscape, consisting of vegetation, topography or the view, can be the first step in determining design, as the goal of the home is to co-exist with the nature around it, not to impose itself upon it.

In Yenna Chan's Sustainable Environments, the Island House designed by Shim Sutcliffe Architects is featured on one of the Thousand Islands in Ontario, Canada. The area still has working dairy farms, and the owners have preserved the nature of the five-acre piece of land by hydroseeding a regional clover mix that is harvested a few times a year. An upper green roof is planted with indigenous wildflowers.

Whether a home is nestled in the mountains, next to water or in a rural setting, the lines of the home are meant to meld with the nature around it, not compete with it. Since the steep topography of the Stavin-Arnholz residence, designed by Travis Price Architects in Washington, D.C., precluded a back yard, the house in the woods added a column structure with pinpoint footing for an addition, leaving all the major trees on the property unscathed. The trees are even integrated into the design, growing through openings in the lower decks. Four levels of multiple decks offer play areas and outdoor living space merged with the woods below.

This connection to habitat offers the architect a way to integrate the exterior and interior climates. Wall types and surfaces, solar chimney and green roofs can benefit from natural means of heating, cooling and ventilation. Known as passive technologies, these systems are design-based and virtually free, contributing to economical, efficient methods of heating and cooling the home. Chan's book says that the last two decades have seen new passive technologies with designs that feature superinsulated exterior envelopes, reduced energy consumption and efficient ventilation and water conservation. Solar principles can eliminate the need for a typical furnace or boiler system. A vegetated roof can aid in establishing a stable thermal environment. It also absorbs carbon dioxide and releases oxygen, helping to reduce the greenhouse effect. Architects are looking at the idea of green roofs around the world to benefit the atmosphere.

A dramatic example of this theory are the green roofs of the Solaire Building in New York. Pelli Clarke Pelli Architects worked with landscape architects Balmori Associates to integrate vegetated roofs and a hydrological system into the Solaire Building, the first sustainable residential high rise in the United States. There is a 5,000-square foot terrace on the 19th floor and a 4,800-square-foot roof on the 28th floor. The planted roofs absorb rainwater and filter pollutants. The runoff goes into a basement system, which is then reused to irrigate the roof and local parks.

Hydrological systems play an important role in all of these scenarios. At the Bercy Chen Studio in Austin, Texas, the house is located on a steep gradient with a creek at the foot of the slope. A system was designed that collects rainwater in pools at the ground floor and channels it down a slope to a storage tank near the creek. This system actually aids in preventing flash flooding in the lower parts of the city by alleviating runoff from thunderstorms.

In Chan's section about the use of sustainable building materials, she writes about the experimentation with new composites and the ingenious applications being applied for more common building materials. She says that many of the recycled elements are not even specified manufactured products.

Renewability and "embodied energy" are two perquisites many architects expect when looking at sustainable materials. The book defines embodied energy as "the total sum of energy associated with the life cycle of a material, from the extraction of raw material, through the processing, manufacturing, transport, use and disposal of the finished product."  Surprisingly, while steel may have a higher sum total of energy due to its manufacturing process, its strength, durability and reusability still make it a good choice for some building projects.

Sustainable woods like bamboo and straw are becoming architectural favorites in whole, minimally processed form. Straw bales actually do a better job than most of the current wall insulation. In North London, Sarah Wigglesworth Architects used straw bales stacked between structural timber ladder frames. A clear window cutout includes the straw insulation as a design feature of the home. Straw's ease of use, low embodied energy, recyclability and low cost give it a great advantage over other methods now used.

In the Great (Bamboo) Wall house in Beijing, Kengo Kuma Architects honored a long tradition of bamboo elements in Asian homes. Wanting to use local materials, the architects used bamboo cane for a wall and ceiling finish throughout the home and as flooring in the bedrooms and lounge area. The larger hollow cane interiors covered up reinforced concrete cores to maintain consistency of the design. With China's heavy construction boom, it is important that renewable resources be employed as much as possible.

While bamboo is easily grown and is a popular renewable resource, it and other wood products need to meet certain certifications guaranteeing that the wood is not an endangered or genetically modified species. Tree farms and plantations are replacing natural forests and destroying natural ecosystems.

Salvaged and recycled materials are other sustainable uses of building materials. Salvage means reusing whole materials that would otherwise be thrown away, while recycling implies a process that takes the element and changes it into another form.

Some of these materials are being experimented with for use in emergency or low-end housing. For example, Sean Godsell Architects has designed Future Shack, which can be easily shipped for disaster relief and housing for developing countries. Recycled shipping containers are the shell of the house with a parasol roof that shades the top of the container and provides some protected outside space. It also has water tanks, a solar power cell, a satellite receiver, a roof access ladder and a container access ramp. It can be assembled in a day.

In Mason's Bend, Alabama, Rural Studio designed Lucy's House with 72,000 pieces of carpet tile. Stacked manually, the carpet squares are held in place by a wood ring beam just below the eaves of the house. Metal columns provide the structural support. Because both the interior and exterior walls do not require any additional finishes, there are considerable cost savings. In addition, it keeps the carpet from going into landfills and saves on the energy required to recycle the material.

A civil engineer commissioned Single Speed Design to build his Big Dig House in Lexington, Massachusetts. He was involved with the Big Dig in Boston, a public engineering project that took apart miles of an elevated expressway to make an underground artery, generating huge amounts of construction waste. Six hundred thousand pounds of the waste material was incorporated into the home's structural components.

Sustainable Environments notes that the public's concern with both present and future environmental problems coincided with a movement away from the theories of formal architecture. This paved the way for sustainable design. Truly avant-garde designs have risen up out of formal and conceptual principles integrated with environmental technology.

The sustainability movement proponents believe that sustainable living will eventually appeal on a mass level because the elements of this type of lifestyle are not only healthier and more comfortable, but they also make people feel more responsible and altruistic. While the sustainable single family home remains something of an oxymoron due to it's percentage of land use per person, it's use of arable land and the fact it is usually far from transportation, it's a lifestyle that is not likely to change soon.

The examples offered in these books do, however, offer an alternative to cookie-cutter, energy-draining McMansions, recently popular in cities and suburbs across the country. With increasing resources to draw upon in terms of new sustainable technologies, recycling and innovative building materials, the sustainability movement's expansion is sure to increase exponentially over the coming years. The imaginative design often associated with these green buildings gives way to a new style of architecture that promotes holistic health and mental well-being while conserving the fast dwindling resources of the planet.

Published: April 01, 2007
Issue: Spring 2007