The “Building an Eco Home” series is nine articles that were originally published in The Healthy Independent while we were in the process of building our current home. I have made only minor edits to include links and format for the online publishing.
What homebuilding options are available to allow you to live more lightly and responsibly on the earth? My husband, August, and I started researching this question more than a year ago when we put our current home on the market and decided to build a new one.
While our current home was well built with a spacious floor plan and lots of natural light, we realized that it is simply not the right house for us. The house itself is larger than our family needs, and the half acre yard is smaller than we would like. We put a lot of time and effort into landscaping and grooming our yard so that it mostly blends into the neighborhood, but we have literally run out of room. We have some gratuitous barren grass lawn, but the back yard is dominated by a large raised bed vegetable garden, deck, gazebo and play area. The rest of the yard is liberally sprinkled with fruit trees, grapevines, raspberries and other fruit, as well as herb, vegetable, annual and perennial flower beds.
Other factors that have led us to our decision to build include: low interest rates, our decision to homeschool our children (thus less concern over what school district we are located in), a desire to become more self-sufficient, and my husband’s love of building. Our goal is to design a practical, energy and water efficient home on more land. This will allow us to provide more of our own organically grown food (and potentially produce extra to supplement our income) while reducing our dependence on fossil fuels and other outside inputs. We also plan to utilize more native and heirloom plantings to create an outdoor habitat that we can enjoy ourselves and share with others. We hope to use our home as an extended “classroom”, first for our boys and eventually for others.
We began by making up a list of things we wanted. Initially, we added to the list without concern for cost. As estimates come in, the list will continue to be refined. While we were developing our “home definition”, we experimented with different floor plans in 3-D Home Architect 3.0. My closet architect of a husband got obsessed and developed more than 200 plans before we settled on a south facing walk out ranch with an open floor-plan and very little hallway space.
To gather ideas for our “eco-home”, we turned to the internet and our public library, as well as friends and professionals who have worked and lived with the materials we are evaluating. We have literally spent months reviewing material on eco-friendly home design, energy conservation, and renewable resources. This has allowed us to eliminate some options, but has opened up many that we were not familiar with, such as ICF (Insulated Concrete Form) construction. Interestingly, but perhaps not surprisingly, we have also found that designs that meet our requirements correlate well with many Feng Shui design principles. (For more information on building with Feng Shui, see Feng Shui Principles for Building and Remodeling: Creating a Space That Meets Your Needs and Promotes Well-Being by Nancilee Wyndra and Lenore Weiss Baigelman.)
Our plans include traditional ideas such as bookshelves sunk into walls, ceiling fans, a full walk-in panty, a combined entry near the laundry and kitchen with seating and storage, a root cellar and rainwater collection, possibly with a cistern. We hope to combine these elements with modern construction techniques such as insulated concrete forms (ICF) or structural insulated panels (SIP), greywater recovery, hydronic and/or radiant heat in the main and basement floors, amorphous photovoltaic films, and a ground source heat pump (geothermal) system or active solar thermal system.
Our floorplan includes bedrooms on both floors, and a small kitchen space in the basement in addition to the main kitchen to allow for “living on one floor” both upstairs and down. To accommodate aging family members and changes in our own mobility, we have integrated Universally Accessible design elements. These simple features are easy to include during construction but can be costly to retrofit. Examples include: low or no thresholds, backing in walls to allow for handles and grab bars, 36” doors, extra wide stairways and hallways, and wide spaces in bathrooms to allow for a wheelchair access. With the aging of the Baby Boomer generation, this type of construction is likely to see a significant increase in demand. For more information on Universally Accessible design see The Center for Universal Design.
Choices for interior finishes also reflect a concern for health and the environment. We plan to use eco-friendly flooring, such as bamboo hardwood, finished cement or ceramic tile, or possibly even linoleum or cork if we can afford it. Low/no VOC (volatile organic chemicals) paints and finishes are also a must. To help us meet these goals we are working with a builder who is Green Built certified. Green Built Home™ is a voluntary green building initiative that reviews and certifies homes that meet sustainable building and energy standards. The American Lung Association’s Health House program has many guidelines that are similar. We may also have the house certified under that program.
The biggest (and simplest) energy-related design element we want to include is passive solar heating and cooling. The ideal “solar home” would be a dome, but a boxy rectangle is a lot easier to build and works quite well. The long side of the house should be located on a roughly east-west axis, so that the majority of the house has some southern exposure. This minimizes winter heat loss and avoids summer overheating from east/west facing windows. Obviously, not every lot is suited to this configuration. Sometimes an L-shaped layout can be used to work around this problem. Thermal performance may be optimized by orienting the home slightly east or west of true south. In the Green Bay area, for instance, performance is improved by orienting the long side 10 degrees east of true south.
In addition to shape and orientation, glazing (glass in windows, doors and skylights) is another important aspect of the passive solar home. South facing window area should be between 7 and 12 percent of the total square footage of the house. Overglazing (too many windows/skylights) was a common problem of early passive solar designs. This leads to extremely high summer temperatures inside the home. Windows should also be planned with some type of overhang to reduce summer insolation (incoming sun). In the Green Bay area, a ratio of 3 to 1 to 2 is recommended. This means that for a three foot tall window, an overhang should be placed one foot above the window and should extend out two feet. This allows low angle winter sun to enter while blocking intense summer rays. South shading from trees or nearby buildings must be limited, especially in the winter. While the majority of windows should be located on the south side of the house, additional windows should be placed on other walls to allow for natural cross ventilation.
Another common problem with early passive solar homes was inadequate thermal mass. A house that has more “bulk”, in terms of thicker walls, tile floors, planters or other elements will change temperature more slowly than a standard “stick built” home. This allows you to store daytime heat in the mass of the house itself. We anticipate that an ICF home would work very well in this respect. In the summer, the home can be vented and cooled at night, then sealed during the day to maintain a lower temperature. Open floor plans promote even temperature distribution throughout the house.
For more information on passive solar design, check out The Solar House: Passive Heating and Cooling by Daniel D. Chiras.
Another “must have” for our new home is certification by Wisconsin’s Focus on Energy program. Focus on Energy promotes energy efficiency and renewable energy use in homes and businesses, providing information, rebates, training and other services. I’ll have more information on this program and other environmentally friendly building options in the next issue.