Sustainable Home Designs
When it comes to sustainable design or architecture, there are many factors to consider. For the purposes of this article, we’ll be focusing our attention on the design needs and challenges for desert dwellings, specifically, the southwestern United States. There are some specific eco-friendly home designs, ideas and techniques that can help a home reduce its energy use and maximize the natural elements from where it is constructed. In addition, there are building costs to consider in building such a home. We’ll explore these points in more detail here.
Before we get into the specifics of desert-adapted sustainable home design, let’s take a minute to discuss what this principle even means. Essentially, the term sustainable is a term that means living in a way that is beneficial for BOTH us AND the planet. It is best described by the idea of living in a way that produces less waste than the environment can absorb – indefinitely – keeping your carbon footprint to as close to zero as possible. This assists not only with pollution and air quality but with other natural resources.
On GreenHomeBuilding.com1 there is a nice resource list of books to become more educated on this topic as it relates to home design and building construction, as well as 13 principles to help guide your design to be more in line with a sustainable plan.
Some of the ideas like “think small, heat with the sun, keep your cool, use renewable energy, conserve water and using local and natural materials” are all points that we’ll address in this article. Let’s address these points and elaborate where needed to make the case more clearly for why eco-friendly homes with sustainable design is the way to build now and for the future.
Small Home Design
The notion of building a home that is small doesn’t mean too small, it means just right. Think of it like building for Goldilocks. A sustainably built home is just the right size for the occupants and their lifestyle. Homes that are excessively large waste not only natural resources and energy in terms of heating and cooling them, but also in the
You can see this very beautiful and functional kitchen, all materials were sustainable products.
materials used to build them. We’ll discuss this a bit further below in the section on using local and natural materials.
Modestly sized homes also allow the natural environment enough space to grow and thrive and support the local wildlife. In areas of forest or desert land, this means less disruption of the natural environment and a more peaceful co-existence of humans and animals. Attacks on both humans and pets have been shown to occur more frequently as natural habitat is destroyed.
Passive Solar Heating
This is a more decorative way of achieving the passive solar heating wall. Others are concrete block or masonry materials.
Heating with the sun is also more commonly known as passive heating or passive solar design. In this design principle, one would orient the home so that it can take advantage of the sun’s natural heating abilities to heat one’s home. It is also an important idea because of how the energy use will be affected by the interior temperature of the home.
Likewise, cooling with the use of orientation and landscape design are key ways to address heating and cooling issues. This is a great method as it relies on no moving parts (apart from any operable windows or fans that may be used to help circulate air) or electrical or mechanical devices.
On SustainableSources.com2 , they discuss the best way to do this is to have the south facing wall of the home be used to ‘trap’ the heat from the sun. This wall can be made of a masonry material or other material that can be used as a thermal mass. This will allow the sun to heat it during the day and then have it radiated into the home when the sun goes down.
In the desert, architecture needs to address this south facing feature. You would not want your home to have a large south-facing design unless you plan appropriately with trees or window overhangs, a patio or other way of blocking the intense summer sun from heating the interior of your home. Window eaves can be built to extend enough to block the sun’s rays from entering in the summer and still get some heating benefits in the winter. This can be accomplished by taking advantage of the height or arc of the sun as it moves through the sky in different seasons. In the summer, the sun is ‘high’ in the sky, so a canopy or eave can block it if it is just the right length or angle. Similarly, in the winter, the sun is ‘low’ in the sky and can shine into those same windows bringing warmth. Proper landscape design will give you shade from native species of trees or shrubs. Also, xeriscaping will ensure that you don’t use excessive water, we’ll discuss this point in the appropriate section below as well.
Keeping Cool
Some of the most effective ways of keeping cool in the desert are to build with orientation and shade in mind. If you do this, you will ensure that your air conditioning unit will not need to work as hard, saving both energy and money in the process. You can also keep the efficiency up and the workload down by building in a unique way that not many builders do, currently (2011).
This is to build the attic space as a semi-air conditioned room. The underside of the roof decking can be insulated providing you with an attic space that is much cooler than a traditional one. Since most duct work is located in the attic, it means that the cold air inside the ducts have to be battling the heat in the attic as it moves through to your rooms. This causes a big cooling loss and requires your unit to work harder and longer to provide a comfortable temperature. Having a cooler attic (by as much as 40-60 degrees) can mean significant energy savings, financial savings and longevity for your unit.
Renewable Energy
Solar power is a currently viable renewable energy solution.
Renewable energy systems are those that can be provided by nature in the course of her life. In other words, styles of energy production, like solar and wind are natural ways to produce energy.
Solar power can be provided by solar panels located on top of your home, a solar panel patio cover or a solar panel array on some property space. Wind energy can also be harvested to help power your home. In the desert, with as many days of sun as we get, solar power is really a perfect choice. Geothermal heating and cooling systems are another way that you can benefit from the core temperature stability of the Earth (50-55 degrees F) to heat and cool your home.
Conserving Water
As mentioned, saving water is one of those facts that simply cannot be overemphasized in the desert. Landscaping must utilize the native plants and vegetation that is suited to thrive in arid and hot conditions. These shrubs, trees, flowers and cacti can provide both aesthetic and functional properties to your overall landscape picture.
Xeriscaping is a term that is used to best describe what plants will work best. When first planted, you will need to water more thoroughly and regularly. Once established, many native plants require little, if any, water to grow and mature. Mature trees, like the Palo Verde and Mesquite varieties can grow quite large and provide very adequate shading. Sites like EnergySavers.gov3 give great information regarding the types of plants to use in your climate zone (the desert is hot-arid and requires special landscape features described here). Shading an air conditioning unit can also increase its efficiency by up to 10%4.
Local and Natural Materials
Where possible, it is always best to use materials sourced as close to the project as possible. This will ensure that you’re using materials that are adequately suited to the environment and it will greatly reduce the energy impact of having to transport and package the materials. Labor costs will also be reduced, drastically. There are other advantages of using natural materials that include more sustainable elements and less toxic problems. Many man-made products have an off-gassing element about them. Natural building materials could include things like bamboo, renewable and sustainably harvested woods, no VOC paints, clay plaster walls, rammed Earth, straw bales, and more. Entire industries exist and have spawned from the development of green building and design.
What are the Costs of Sustainable Design?
This is a question that is probably more likely to stir debate than any other. According to the Whole Building Design Guide (WBDG.com5)
“The main objectives of sustainable design are to avoid resource depletion of energy, water, and raw materials; prevent environmental degradation caused by facilities and infrastructure throughout their life cycle; and create built environments that are livable, comfortable, safe, and productive.”
So, the real question is, what ‘costs’ are we talking about? Costs in terms of building design and ecological principles – as they pertain to sustainable design – or bottom line, dollars and cents costs.
If we are talking about the first scenario, then it is obvious that a home built with sustainable elements and features ‘costs’ less in terms of damage to the environment in relation to its overall benefits to both inhabitant and planet.
However, in terms of financial costs, building green does typically cost anywhere between 5-20% more. The majority of this extra cost is to be found in using alternative building materials or the extra labor necessary to ensure more properly fitted duct work, using high efficiency appliances and building materials that may cost more but can be found locally or will use less energy in the long run.
Additionally, solar water heaters and tankless water heaters make for great alternatives to the conventional water heater but also cost more.
A typical, 2,000 square foot home of conventionally built materials may cost between $80-120 per square foot6 (average $100 psf). For the same sustainably built home, it could cost roughly an average of $105-120 psf. One other main problem with calculating specific cost differences has to do with the up-front vs. life-cycle cost of these types of buildings. Many of the sustainable features and design elements; like energy systems, appliances, lighting and building materials cost more initially, but are much less overall if computed on a lifetime basis. To truly appreciate what sustainable home designs can do for both the health of the occupants and that of the planet can also only be appreciated in terms of a life cycle as well. Live well!