In our last blog, we purchased our property and visited the local jurisdiction to make sure we can do what we want with our property. We also made sure it met our minimum requirements for insurance, safety, medical care, and services. Now it’s time to consider what kind of house we want to live in for our off grid experience.
There is no “best in category” type of house for off grid living. There are however, many different design considerations that can be incorporated into your home of choice that directly correspond to being off the grid. The most critical one is energy efficiency.
Just think of all the different types of homes available to you today. Tepees, yurts, cabins, manufactured homes, mobile homes, traditional stick frame, insulated concrete forms (ICF), structural insulated panel (SIP), log home, cob, cordwood, straw bale, adobe, earth berm, underground, steel, steel container box, concrete, and masonry (brick, block, and stone). Don’t forget houseboats!
Remember, we each have our own set of circumstances that factor into the choices we make so the trick here is not to get too hung up on which kind of house is better for living off grid but rather to make the most of the one you choose or already own.
We decided to go with an insulated concrete house. One of the biggest factors is that we live 20 miles from the nearest fire station and wanted to do everything we could to be non-combustible. The ICF design is also fairly energy efficient and easy to upgrade structurally to withstand earthquakes and heavy snow loads. In our first year of living here we have experienced a 4.6 magnitude earthquake and a forest fire that would have consumed our house except for the precautions we took in constructing a defensible area around the house and the non combustible nature of the materials we used on the exterior walls, roof, and soffits.
Our exterior walls consist of Hardiplank siding over 2” (3 hour fire treated foam) insulation board attached to an 8” concrete wall with another 2” layer of fire treated insulation on the inside. The roof is constructed of metal panels and the soffits are covered with vented or slotted metal panels which eliminate bird blocking holes. We even used metal panels on the carport and porch roof exposed ceilings. One of the main causes of house fires from an exterior source is when the wind blows fire embers into your attic via the bird block attic vent holes.
Non combustible construction could also be a factor with your insurance company.
Anyway, back to energy efficiency. The more energy efficient your house is, the less energy you are going to use to run your household. Less energy to run your household will result in a smaller energy source. The smaller the source, the less money you will pay to purchase and install it. I know you off-grid readers already know that but it made me feel better just to say it!
Considerations you need to make affecting energy efficiency include but are not limited to construction materials, insulation, window size and location, the direction your home faces, how much of your home is above ground, the size of your home, eave (overhang) length, ceiling heights, appliances, heating, and electrical fixtures. I’m sure with a little more time I can add to this list. It may seem a little overwhelming but the good news is look at all the ways you can save energy and the decisions and choices are yours to make.
We’ll address these items one by one to help understand what effect each one has on energy efficiency.
Construction Materials: I’ve already explained the factors we used in determining what to build our house with. Strength and non combustible materials. Factors for you may be entirely different. I personally would love the atmosphere of a log home under other circumstances. For many of you cost will be the biggest factor. Manufactured homes and mobile homes are more affordable types of construction and have come a long way in terms of quality from years past. If you want to be close to nature and simplicity, maybe the tepee or yurt is for you. Straw bale, cob and cordwood are good “do it yourself “materials. Masonry can be a good choice in terms of appearance and insulation efficiency. Whatever your circumstances are, just do the best you can to utilize the most energy efficient materials available to you.
Insulation: The type of insulation you utilize will depend on the type of construction you choose. We used insulated concrete forms which doubled as our concrete wall forms and exterior insulation plus fiberglass blown in over the ceilings. We also applied insulation batts in the ceilings at the exterior wall line. We used the earth on one side of the house because we built on a slope.
There are many choices available to you today. Rigid foam insulation, batt (fiberglass) insulation, blown insulation and polyurethane insulation. No need to go into detail here. The important thing to remember is that all materials and types of construction can be insulated. Any part of your house that you can place below grade is the best insulation of all. Properly designed, insulation can help to keep your house warm in the winter and cool in the summer. Straw bale, cordwood, cob, and log walls act as their own combo insulation and exterior wall systems.
In the late 1970’s I built my first home with my Dads help. Being 20 years old and having insulated a few houses for my Dad I thought I knew a lot about insulation. Our local utility offered a free energy survey and if you followed their advice in “draft proofing” your home they would give you the materials to plug the holes and your monthly bills would go down. I thought it was a waste of time but I would give them a shot anyway. After all, I had done my own insulating and knew what a good job it was. It was a traditional stick frame home. During the survey I was so busy rolling my eyes that I almost missed the toilet paper test. Remove an electrical outlet or light switch cover and loosely hold a few squares of toilet paper in front of it and watch it flutter from all of the air passing through the opening. Without further comment (or rolling of the eyes) I accepted their free foam plugs to put behind the switch and outlet covers. To this day I have no idea where that air comes from but I do know it exists if you don’t plug all of the holes including the small ones.
I’m not going to get into whether or not it is best to “seal” a house or whether it is harmful to your health. The fact is, the international residential building code is headed in that direction and in some cases are already here. As of January 2011, some building departments began doing pressure tests on new homes. Using a huge fan they blow a prescribed amount of air into your home from an exterior doorway which creates a positive and measurable pressure inside the house. If your house can’t contain and hold that amount of pressure for a certain length of time they will not let you move in until all of the leaks are identified and plugged. It is my understanding that most houses pass the test. I have mixed feelings on the subject. I understand the need for energy conservation however you never heard the term “sick building” until the late 1980’s when we began to seal up buildings for energy purposes. I think I’ll let someone else tackle that blog.
Coming up: window sizes and locations, the direction your home faces, how much of your home is above ground, the size of your home, eave length, ceiling heights, appliances, and electrical fixtures.