10 Environmentally Friendly Architectural Styles

Living in earth-sheltered housing doesn't have to mean sharing your space with the worms. With designs that are partially below ground or completely above ground, earth-sheltered housing is adaptable and takes advantage of the energy efficiency of the surrounding soil and plant life. Architect Malcolm Wells advocated and promoted the earth-sheltered architecture until his death in December 2009 [source: Weber]. He designed multiple underground homes, stadiums, airports and even bridges, and though many never came to fruition, they did forever influence the green movement [source: Weber].

One earth-sheltered design that has taken hold today is the bermed home. It is built at ground level or dug into the hillside and has earth compacted around two sides, the top/roof and along the rear. Homes like these have sub-ground living areas with central atriums or large courtyards that provide natural light, cool air and insulation.

According to the U.S. Department of Energy, elevational bermed homes, usually those situated partly in the ground with a south-facing wall open to sunshine and heat, may be the most affordable options in earth-sheltered housing. They're easier to construct and often are built into hillsides, taking advantage of natural surroundings. Underground earth-rammed homes may be more costly, but they're not covered with as much earth as you might think -- typically less than 3 feet (0.9 meters). Using more than 3 feet doesn't increase energy efficiency [source: U.S. Department of Energy].

For decades, "weird," "amazing" and "unusual" homes found their way into the spotlight because of their non-traditional make up. Bottles and cans, old tires, and other trashed and found items became building materials for recycled architecture. Many of these structures are green because they reuse available items, but often they go further by incorporating other eco-friendly ideas. And though some are quirky and funky by design, others have an air of elegance because of their finished details and traditional craftsmanship.

A recycled modern home doesn't have to be made of 6 million empty beer bottles, as is the case with La Casa de Botella in Argentina, but planning a house that embraces irregular sizes and design in order to use recycled materials is realistic without having to be extreme or newsworthy [source: Alvarado]. Directories published in the United States and Canada by the Building Materials Reuse Association (BMRA) help builders find local sources for deconstructing and reconstructing -- taking good care to preserve materials you're taking down and selecting reuse materials for building up.

Building with roof rafters from an old factory or insulating walls with old denim are less visible possibilities, and if you still want to use an old ship's bow for a front porch, anchors aweigh.

A forerunner in promoting environmentally friendly architecture was engineer Buckminster "Bucky" Fuller. He sought to realize the idea of "doing more with less," and in building design, he tried to popularize the half-circle geodesic dome. Made up of interconnected triangles, which use a minimum of materials to create an open space for living, the domes were thought to be ideal because of their low cost and sturdiness [source: Black Mountain College].

An earlier form of semi-sphere living was the yurt, which goes back thousands of years to traditional Mongolian tent living. With circular walls built up in one layer or many layers of circles, a yurt is kind of a strong tent that survives harsh conditions and has a simple set up.

Both of these forms are organic, borrowing from the design of natural forms on the Earth and in the body -- such as cells -- and they use fewer materials. Yurts, domes and other organic forms are not the most traditional choice in contemporary eco-friendly housing, but manufacturers in North America sell homes in the style of domes and tents in an affordable range. And in some parts of Asia and Africa this traditional style is still the most popular, sturdy and economical choice.

As the need for affordable, well-made and energy-efficient housing increases through challenging economic times, and as families learn more about the toxins in the very materials that surround them at home, some eco-conscious developers are buying in bulk and buying green to keep costs down and fill a market need.

Tract housing units in states ranging from Arizona to Washington to New York have been finding investors and buyers who are building eco-friendly from the ground up. Builders who still get behind the ease and low cost of prefabricated housing also have shown green growth by adding options for energy efficiency and non-toxic features in their pre-built cottage, solar and modular home packages.

Though doing some research into the green claims of companies marketing tract and prefab is advisable, there is one quality that many of these companies seem to have in common: You get more energy efficiency and make a smaller footprint on the environment, and you will likely get a smaller house, too.

Most people associate adobe- and pueblo-style with hot, dry areas such as the Southwestern United States, Mexico, and parts of Africa and the Mediterranean. The homes built with adobe blocks or bricks made of a clay, water and sand mixture can last hundreds of years, and they provide excellent insulation from hot and cold weather, even though they're more widely found in warm, arid climates [source: Encyclopaedia Britannica]. Having adequate and regular sunshine to keep the adobe dry and to allow it to store heat energy is a must. Adobe has a low R-value, meaning it doesn't insulate as well outside of its ideal, dry and sunny environment, but its thick make up is very eco-friendly in terms of keeping the heat out [source: U.S. Dept of Energy]. In cold climates, it's possible to add insulation and counter any moisture, though it makes more sense to work with other materials more suited for the environment [source: Roberts, et al.]

Adobe- and pueblo-revival continue to be most popular in warm regions, and what makes them "revival" is they combine traditional clay materials and newer insulating and strengthening ingredients like concrete and paper composites, and sometimes applied exterior plasters, as well. Although the revival in this style started back in the 1920s and '30s, it has continued into the 21st century with its characteristic simple lines, central courtyards and wooden architectural details often with modern tweaks and varied rooflines.

Stacks of dried out muddy-looking rectangles with a dirt smell and crumbly corners might be one way people imagine rammed-earth construction. However, centuries-old European homesteads, ancient Asian landmarks, and modern, sleek and efficient Western designs stand up against this stereotype. Crude forms of rammed-earth building in impoverished areas of the world do usually lack the polish of contemporary styles, but most share an amazing longevity and energy-efficiency.

Rammed-earth construction is simply the use of soil -- with a weighted mix of clay and sand -- packed super tight into brick form or packed up in layers within wooden molds to form walls. These blocks and walls are at minimum about 12 inches (30 centimeters) thick, but can be twice that, and they often have added external treatments to increase insulating properties and durability against weather extremes [source: Encyclopaedia Britannica]. Untreated walls are hardy too, but depending on the climate, modern techniques, such as moisture barriers or strengthened concrete mixes, can improve resilience.

Building a rammed-earth structure will lower energy consumption and costs, but due to the time, labor and transport involved, costs are much higher than in traditional homebuilding [source: California Energy Commission]. Working with local building codes for this unusual building type adds some work too, but long-term and possible lifelong energy savings in an Earth-friendly, earth-filled home may balance the initial time and costs.

Living with shared walls or common spaces and interacting with neighbors isn't for everyone, but like-minded renters and homeowners might be heading toward more planned and communal properties, bringing social lives and work closer to where they actually live. A January 2011 study sponsored by the U.S. Environmental Protection Agency's Smart Growth Program finds that one of the factors that would significantly decrease energy consumption is to focus building and community planning on multifamily or attached housing with shared walls that hold in more heat and increase efficiency [source: EPA]. Building homes closer together and closer to public transit options -- and with more energy-efficient construction -- could reduce consumption up to 64 percent compared to single-family, remote suburban homes that rely heavily on car travel [source: EPA].

Having a single-family home without shared walls is a dream and long-term goal for many, but condos, row houses and cohousing offer options for private ownership and shared responsibility for resources. Some have the added initiative of being responsible to each other in communities as part of the stewardship. Sharing a wall with a neighbor isn't what it used to be. For many, it's a preference and obvious choice toward a smaller footprint and a return to knowing their neighbors.

Many people in the West have grown up living in and visiting homes with lots of small rooms connected by narrow hallways, with little connection to the outdoors. But mid-century modern homes were different -- they had open plans, more natural flooring, and interior courtyards or sheer walls and glass sliders to the outside. Houses from the 1960s by architecture firms like Eichler Homes continue to be hot commodities, and many 21st-century, eco-friendly designs have been inspired by the clean lines and efficiency of this style. With well-joined building envelopes, often achieving a hermetically sealed feel, and the circulation of free-flowing spaces and ventilation -- some with movable walls and tracks for true indoor-outdoor living -- this mid-century modern redux is bringing modern eco-technology to a treasured design style.

Another twist is the adaptation of mid-century modern to multi-unit residential design. Housing developments from the Netherlands to South America show the influence of mid-century modern open planning but in a stacked, urban housing form that departs from the apartment style of connected, closed off small boxes. Greening this multi-unit building is breathing new life into this common housing design.

Downsizing isn't something desirable in the workforce and often it's something brought on by circumstances and not by choice, but for the eco-conscious, it's often a conscious and deliberate move. Criticism of "McMansions," those super-huge, mostly soul-less and resource-wasteful houses of the suburbs have given way to more and more coverage of small, tiny and even micro-homes. Living in small spaces is a necessity for most city-dwellers in high-density areas like Hong Kong and New York City, but many people are exploring building and buying small in order to live more simply and with fewer drains on resources. Sometimes, though, the environmental benefits are just a result of homeowners wanting to pay less for utilities and shorten their commutes, making downsizing good for the wallet, too.

Economic downturns lead to downsizing as well, and according the U.S. Census Bureau, the size of newly built single-family homes decreased between 51 and 200 square feet (4.7 and 18.5 square meters) from 2008 to 2009, making the national average about 2,400 to 2,500 square feet (223 to 232 square meters) [source: Heavens]. Those weathering the economic downturn in Japan also have turned to even smaller spaces, with closet-sized houses and "ultra-tiny" designs growing in popularity [source: Lah].

Some families, however, make a very deliberate decision to live in smaller spaces to be more eco-friendly and to help other families in the process. The Salwen family from Atlanta, for example, sold their house, bought one half its size and used the remaining money to help those in need in Ghana [source: Salwen]. As one of the principles of being environmentally friendly is to lessen negative impacts on the planet -- including its people -- the Salwens lowered their consumption and improved the conditions of others with the money they saved.

If you've read articles on people who live in $200, 24-square-foot (2.23-square-meter) shacks made from junk or who sleep in capsule hotel rooms the size of old phone booths, you might have wondered if these are the wave of the future [source: Wadler]. People in London, Mexico City and the United States are using old shipping containers as homes, and the Keetwonen student dorm complex in Amsterdam is a veritable village of containers used to house more than 1,000 university students [source: Open Architecture Network].

Just as mid-century modern designs by Joseph Eichler in the 1960s didn't take off wildly during their time, but have since become models for reproducing and gleaning the best of their kind, some of what we see today as wacky may lead to practical innovations in mainstream green, environmentally friendly housing. Architects and designers coming into their own today have grown up with the greening of architecture, so it's likely to be less of an afterthought and more a part of good, holistic housing of the near future, with or without the miniature size, high cost and funky functionalism.