Taking Cues from Nature for Sustainable Housing
It seems everything we create these days goes against the laws of nature. We make products from toxic and non-biodegradable materials. If something breaks, we buy a new one instead of attempting to fix it. We tear through environments so we can erect miles of buildings. But what if we could build beautiful structures, be symbiotic with the environment, and even save some money in the process?
Our surrounding nature provides all the materials and inspiration we need to build our houses. For thousands of years civilizations have created sustainable dwellings out of pure necessity, but our society has strayed away from harnessing nature in a viable way. Sustainable housing practices don’t have to be big changes like putting a windmill in your front yard. By working with nature instead of against it, we can build sustainably with minimal changes to our housing expectations.
Sustainable Building Materials
It takes a lot of materials to build a home, most of which are often not sustainably sourced. When considering building materials, think about how they can impact the environment. Energy efficiency is important to reduce heating and cooling loads, leading to lower carbon emissions. The lifecycle of a product must also be considered. How sustainable is the production process? Is the product recyclable or biodegradable at the end of its life? Many new innovative building materials improve on these aspects compared to traditional materials.
Products such as spray foam insulation and asphalt shingles are fabricated from petroleum products and cannot be recycled. There are many new products made from recycled materials that can replace traditional insulation, flooring, roofing, and countertops. Recycled plastic is being made into carpet, tiles for flooring, and countertops. Instead of using raw timber to create wood flooring you can buy reclaimed wood flooring and refurbish it. An insulation product using recycled cellulose can provide comparable R-values to fiberglass insulation.
By considering materials made from recycled materials, we can divert solids from waste streams, use fewer natural resources, and use less energy during the manufacturing process.
Renewable and Local Materials
It’s also important to consider how quickly a material can be replenished in the environment. Traditional wood flooring is made from raw timber. Although this is a renewable material, there are materials more readily available that have even faster harvest cycles. Materials for flooring such as bamboo and cork can be harvested every five and nine years, respectively.
Where construction materials come from is also notable. Instead of shipping in construction materials, we can look at our local resources, which lowers transportation costs and emissions. Materials made from different natural earth ores can be found locally and help steer us away from petroleum-based products.
Optimizing Heating and Cooling Needs
Buildings are designed as big boxes that are arbitrarily oriented so we can fit as many as possible on a plot of land. We spend thousands of dollars every year heating and cooling these homes so we can stay comfortable year-round. But we can reduce our heating and cooling costs by taking advantage of the earth’s natural properties.
Passive Solar Design
The first property is the path of the sun through the sky. The orientation of a house and its windows greatly affects how much heat and light it takes in from the sun. Ideally, we want to steal heat from the sun during the winter and avoid absorbing heat from it during the summer. Designing a building with this in mind is called passive solar design.
Passive solar design will orient a home lengthwise along the east-west axis with windows facing the south side of the building (for the northern hemisphere, but in the southern hemisphere the windows should be north-facing). This orientation allows us to take advantage of the different arcs the sun follows during each season. During the summer, the sun’s path will be higher in the sky and create a steep angle of sunlight to the ground. Using small overhangs, we can block the summer sun from entering the windows and heating the house. During the winter, the sun doesn’t reach as high and creates a lower angle of sunlight to the ground. The sunlight is then able to enter the south-facing windows during these months to heat the house.
Strategically placing rooms throughout the house can also aid in natural light distribution. Rooms that you use most frequently, like the living room and kitchen, should be placed on the south side so they can be naturally lighted by the sun.
Using the same logic, we can plan out where foliage will further improve the heating or cooling demands. Deciduous trees can be planted on the south side, where they will lose their leaves in the winter and allow natural light into the home. Evergreen trees located on the north side will aid in shading during the summer months.
We can also take advantage of the earth’s natural thermal mass properties. Starting at just feet below the ground, the earth is staying at a constant temperature (roughly 55 ℉). You may have noticed this phenomenon if you have ever walked into a basement. Basements seem cooler in the summer and warmer in the winter months. This is because it is insulated by the surrounding earth which is helping the room stay at the same constant temperature.
Geothermal heating and cooling systems run pipes filled with liquid deep into the ground. These systems can be open or closed loops, but the goal is the same, to absorb from or disperse heat into the ground. Compared to traditional HVAC units, geothermal heating and cooling can cut energy bills up to 65%. You benefit from savings. The environment benefits from lower electricity demands and lower carbon emissions.
If the landscape allows, houses can also be built into the earth to take advantage of the natural insulation. Earth-sheltered homes can look beautifully blended into the landscape around them and are protected from any harsh weather. It only takes earth berms covering one or more walls to take advantage of the earth’s heating and cooling properties.
Efficiency is Key
Using fewer resources like water and electricity reduces our impact on the environment. Although helpful, it doesn’t have to mean shorter showers or fewer appliances to reduce your impact. Informed decisions on appliances and fixtures can greatly reduce the amount of energy your home requires. We can save water by installing rain capture systems such as rain barrels to use for irrigation or other non-potable water applications. Even with a sustainably built home, it’s important to continue living with a small environmental impact.
Do Your Part
Green buildings are slowly regaining popularity as society realizes the importance of sustainability. With the trend comes new proof that sustainable housing doesn’t have to mean sacrifices or unpleasant design. Whether you are building a home from the ground up or making small changes to your existing home, we each can do our part to create a circular, sustainable community.
Check out these Platinum LEED accredited buildings full of beautiful sustainable designs.
- Sierra Nevada Brewing Company
- Phipps Center for Sustainable Landscapes
- Casa Aguila
- Centre for Sustainable Chemistry
- Taking Cues from Nature for Sustainable Housing - April 29, 2021
- How K12 Environmental Education Shaped My Career Path - February 11, 2021