Our Motivation?
We have many, the one that drives us the most is summed up perfectly by a Native American proverb...
"We do not inherit the earth from our ancestors,
we borrow it from our children"
"We do not inherit the earth from our ancestors,
we borrow it from our children"
I will be blogging our process and experiences here and will explore specific aspects of the house and our cars in more details in separate web pages. Links to those can be found below or they can be found at the top of the page.
We also have a "Partners & Resources" page where we list many of those that helped us reach our dreams. If you are interested in building a Net Zero house, want more information on energy efficiency, or just like some of the neat stuff in here, you can find links to each company there.
That page will also have links to other resources for information about energy efficiency that are not necessarily directly involved in building our dream house.
We also have a "Partners & Resources" page where we list many of those that helped us reach our dreams. If you are interested in building a Net Zero house, want more information on energy efficiency, or just like some of the neat stuff in here, you can find links to each company there.
That page will also have links to other resources for information about energy efficiency that are not necessarily directly involved in building our dream house.
Whether you are just curious, interested in building your own highly efficient home, interested in electric cars, or want to live in a healthier home, there is something here for you.
When I say "net zero house" I am using the common definition of a house that produces as much energy as it uses over a year.
In our case, there is a bit of a twist. In addition to the energy our house uses over a year, our house also produces as much energy as our cars use over the span of a year!
While energy efficiency is a big part of our project, other aspects are just as important.
These include Health, conservation and economic health.
In our case, there is a bit of a twist. In addition to the energy our house uses over a year, our house also produces as much energy as our cars use over the span of a year!
While energy efficiency is a big part of our project, other aspects are just as important.
These include Health, conservation and economic health.
With focus on low, or no VOC sealants, paint, etc, very few carpets to collect allergens, and a heating system that doesn't spread particulates, we feel healthier in our new house than we ever have.
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We want to minimize our water use.
Although we are blessed with an abundance of fresh water in Minnesota, any water we use needs to be treated, and much of it heated as well. This means saving water also saves energy and places less stress on our city's infrastructure. |
We made sure to use local material when ever possible. This both minimized the energy required to transport the materials and contributed to our local/regional economy.
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Net Zero is just the beginning!
We gave preference to companies/manufacturers that work in environmentally friendly ways.
That could include:
The longevity of a product, or the entire house, also plays an important role.
For example, if you buy a poorly made shirt, it may not last too long.
One very well made shirt that lasts ten years will save more energy than ten shirts that fall apart each year, even if the well made shirt takes twice as much energy to make.
That could include:
- Using recycled content in their products
- Use renewable energy for their manufacturing and/or transportation
- Producing products without using toxic or harmful components such as volatile organic compounds (VOCs).
The longevity of a product, or the entire house, also plays an important role.
For example, if you buy a poorly made shirt, it may not last too long.
One very well made shirt that lasts ten years will save more energy than ten shirts that fall apart each year, even if the well made shirt takes twice as much energy to make.
Meet Our Team
These are the team members that make our Net Zero house what it is:
Structure |
Resources |
Power Draws |
Everyone likes a warm coat outside in the winter, so does your house!
One of the most important things that makes a home energy efficient is the envelope of the house.
The envelope of a home is comprised of the walls, windows, roof and foundation.
The goal is to have as little transfer of the warm air from inside escape to cooler air outside (or the reverse in the summer).
This can happen through air movement, due to drafty windows for example, or through thermal transmission of heat, also called thermal bridging.
For the first, you want to eliminate or minimize holes and unnecessary joints. Every angle is a weak spot, so minimizing those makes the home better insulated. A good vapor/moisture barrier and careful wrapping around windows and doors is also very important.
Thermal bridging happens as thermal energy wants to equalize, warm air will travel from warm to cool.
You can see how thermal transmission works by cooking something in a pan. When you turn on your stovetop, you aren't heating the food directly. You are heating the pan, which then heats the food.
In a house, you don't want that thermal energy to escape. If the walls were made of metal, in the winter, it would be very easy for the warm air inside to warm the metal, which then would try to warm the cooler air outside.
Wood doesn't transmit heat as easily as metal, but it still does.
For this reason, a house with studs every foot will transmit more heat to the outside that a house with studs every two feet.
In our house, we built the walls out of a 2x4 stud wall, then a gap, then another 2x4 stud wall.
This way most of the wood is not continuous through the entire wall, minimizing thermal bridging.
Another advantage to this is it gives us lots of space for insulation and costs less than some other advanced framing techniques.
If you are interested in a more detailed, technical description of thermal bridging, Wikipedia.org has a great description.
The envelope of a home is comprised of the walls, windows, roof and foundation.
The goal is to have as little transfer of the warm air from inside escape to cooler air outside (or the reverse in the summer).
This can happen through air movement, due to drafty windows for example, or through thermal transmission of heat, also called thermal bridging.
For the first, you want to eliminate or minimize holes and unnecessary joints. Every angle is a weak spot, so minimizing those makes the home better insulated. A good vapor/moisture barrier and careful wrapping around windows and doors is also very important.
Thermal bridging happens as thermal energy wants to equalize, warm air will travel from warm to cool.
You can see how thermal transmission works by cooking something in a pan. When you turn on your stovetop, you aren't heating the food directly. You are heating the pan, which then heats the food.
In a house, you don't want that thermal energy to escape. If the walls were made of metal, in the winter, it would be very easy for the warm air inside to warm the metal, which then would try to warm the cooler air outside.
Wood doesn't transmit heat as easily as metal, but it still does.
For this reason, a house with studs every foot will transmit more heat to the outside that a house with studs every two feet.
In our house, we built the walls out of a 2x4 stud wall, then a gap, then another 2x4 stud wall.
This way most of the wood is not continuous through the entire wall, minimizing thermal bridging.
Another advantage to this is it gives us lots of space for insulation and costs less than some other advanced framing techniques.
If you are interested in a more detailed, technical description of thermal bridging, Wikipedia.org has a great description.
The heart of our HVAC system
Geothermal Heat Pump
For comfort as well as health a good HVAC system is a requirement.
We will be using a ground source closed loop heat pump, also called a geothermal heat pump.
Not only are we using a geothermal heat pump for our heating, we are also using it for our domestic hot water.
In addition, we have an Air Handler which uses forced air when/if the infloor heat isn't fast enough or has trouble keeping up and operates a compressor to concentrate the heat from the loop field.
How does a heat pump work? Well, have you ever noticed on a refrigerator with coils on the back, how the coils heat up? Or perhaps how an air conditioner unit that sits outside heats up?
That is basically how any system that cools something works, it transfers heat from the place you want to be cool, to another location. Basically it is just moving heat from one place to another.
Your refrigerator takes heat from inside and then transfers that to outside the fridge where it can cool off.
Many of these systems will use a liquid of some sort, because liquids hold heat better than air.
A geothermal heat pump works the same way. The ground (below about 10 feet) is always about 55 degrees, winter or summer. The system uses a series of tubes that carry liquid through the earth, returning that warmth to the house and concentrating it.
This can also be done to exchange heat from the air outside instead of the ground. This is less expensive, however, it is also much less efficient as it gets colder outside (you can only get so much heat out of air that is zero degrees).
The advantage to using the ground as a source of heat is it is always between 50 and 60 degrees below 10 feet.
And in the summer, rather than trying to move heat out of the house into the air that may be 80, 90 or more degrees, it is much more efficient to dump that heat back into the earth where it is still about 55 degrees.
We are designing the HVAC system with a number of zones in the house. This will allow us to only heat of cool areas of the house we are in, or expect to be soon.
The ventilation system also has a number of interesting aspects not normally seen in residential HVAC systems.
For example, small rooms, that still require a vent, may have smaller vents. No need for a closet to have the same size fresh air vent as a bedroom four times the size.
We also are taking precautions to plan out the ductwork paths carefully. We want to minimize bends and turns in the ductwork as well as have short runs of the ductwork. The longer the path is, as well as the more turns in the ductwork, the more energy it takes to move the air through it.
Fresh Air Exchanger
Our house is very highly insulated with very little natural ventilation. For comfort and health, we need to provide fresh air.
We are doing this with something many modern houses use, an Energy Recovery Ventilation (ERV) system.
This system will take air from inside and run it past air it takes in from the outside through a series of vents. This is done in such a way that the heat and humidity is taken from the inside air and transferred to the fresh air from outside. Once warmed, or cooled, the fresh air is released through the HVAC system. This also helps prevent the inside of the house drying out as much in the winter!
Conserving water saves energy and money.
Outdoors - Water management and treatment
Although we have lots of fresh water in Minnesota, it is not limitless and is closely tied with energy.
When rain falls on a solid, non permeable, surface, it runs off, typically into the street and sewer.
As it does this, it picks up pollutants and debris. This then runs through our sewer systems and water treatment plants.
Alternatively, if fewer surfaces are non permeable, that water can soak into the soil. As it does, plants filter the water naturally. Saving energy, keeping pollutants out of our streams and rivers, and, the plants like it!
Thanks to some great information, and help from Rice Creek Watershed District, we became aware of a program in which we can install strategically placed curb cuts to allow water from the street to flow through the 'curb cut', into a rain garden and then back to the street.
The rain garden is designed to take in that water, and let it soak into the ground over time.
Rain gardens are planted with plants that will help absorb that water and filter it naturally.
If there is too much water for the rain garden to handle, such as a heavy storm, the excess water will overflow the capacity of the rain garden and return to the street (where it would have remained if we had not had the rain garden).
Combined use of permeable surfaces, careful sloping of non permeable surfaces, rain gardens and curb cuts, allows us to treat all the rain that falls on our lot, as well as some of the water from the street and filter it naturally.
Outdoors - Water conservation
Of course, the rain doesn't always fall when we want it to (sometimes it seems as if it doesn't fall at all!).
Our yard is being designed to require little, to no irrigation from us (once the new plants are established).
Southview Design is helping us design landscaping that will require no more than normal rainfall, and perhaps a little bit of irrigation from our rain barrels in the driest weather.
Any guesses as to what is the thirstiest part of the typical yard?? If you guessed grass, or turf, you would be right!
We are going to have a bit of grass in our landscape. The grass is called "Tall Fescue" and I have been using it for a couple years where I live now. I have not, once it was established, watered it in two years.
Besides using this drought tolerant grass, most of the yard will be Xeriscape. Very little water will be required by this landscape once the new plants have become established.
Indoors
Speaking of heating water, this is one aspect of the house I am very much looking forward to.
For our domestic hot water, we are planning on a system that uses geothermal energy.
Inside the house, we make extensive use of low flow faucets.
By using less water per minute, a hot shower uses less energy as not as much water needs to be heated.
This is most useful at faucets such as showers, vanity sinks and such.
At other faucets, such as a kitchen faucet, low flow faucets are not so useful as typically you are looking to fill a pot or glass of water. You use the same amount of water, the low flow faucet would just make that take longer.
Although we have lots of fresh water in Minnesota, it is not limitless and is closely tied with energy.
When rain falls on a solid, non permeable, surface, it runs off, typically into the street and sewer.
As it does this, it picks up pollutants and debris. This then runs through our sewer systems and water treatment plants.
Alternatively, if fewer surfaces are non permeable, that water can soak into the soil. As it does, plants filter the water naturally. Saving energy, keeping pollutants out of our streams and rivers, and, the plants like it!
Thanks to some great information, and help from Rice Creek Watershed District, we became aware of a program in which we can install strategically placed curb cuts to allow water from the street to flow through the 'curb cut', into a rain garden and then back to the street.
The rain garden is designed to take in that water, and let it soak into the ground over time.
Rain gardens are planted with plants that will help absorb that water and filter it naturally.
If there is too much water for the rain garden to handle, such as a heavy storm, the excess water will overflow the capacity of the rain garden and return to the street (where it would have remained if we had not had the rain garden).
Combined use of permeable surfaces, careful sloping of non permeable surfaces, rain gardens and curb cuts, allows us to treat all the rain that falls on our lot, as well as some of the water from the street and filter it naturally.
Outdoors - Water conservation
Of course, the rain doesn't always fall when we want it to (sometimes it seems as if it doesn't fall at all!).
Our yard is being designed to require little, to no irrigation from us (once the new plants are established).
Southview Design is helping us design landscaping that will require no more than normal rainfall, and perhaps a little bit of irrigation from our rain barrels in the driest weather.
Any guesses as to what is the thirstiest part of the typical yard?? If you guessed grass, or turf, you would be right!
We are going to have a bit of grass in our landscape. The grass is called "Tall Fescue" and I have been using it for a couple years where I live now. I have not, once it was established, watered it in two years.
Besides using this drought tolerant grass, most of the yard will be Xeriscape. Very little water will be required by this landscape once the new plants have become established.
Indoors
Speaking of heating water, this is one aspect of the house I am very much looking forward to.
For our domestic hot water, we are planning on a system that uses geothermal energy.
Inside the house, we make extensive use of low flow faucets.
By using less water per minute, a hot shower uses less energy as not as much water needs to be heated.
This is most useful at faucets such as showers, vanity sinks and such.
At other faucets, such as a kitchen faucet, low flow faucets are not so useful as typically you are looking to fill a pot or glass of water. You use the same amount of water, the low flow faucet would just make that take longer.
Our energy comes from a fusion generator!
Our solar panels will absorb, and convert energy from our local fusion power plant (located some 93 Million miles away) into enough electricity over a year to run everything in our house as well as both of our electric cars!
I will be continue to update how well our plan is working in my Blog.
Our home will be powered solely by electricity.
We have no natural gas appliances, we don't even have natural gas lines running to the house.
Solar Benefits
The amount of solar energy falling onto the surface of our parking lots, residential roofs, commercial and industrial rooftops, etc. is truly amazing.
Basically you could generate as much energy as the world uses with enough solar panels to cover an area a bit larger than the state of West Virginia (see this link for details).
So in addition to the fuel being free, the fuel also never spills. O.K. technically it does, but when there is a solar panel spill we call it a "nice day"!
There is no waste product from the fuel. No coal ash storage pits, no nuclear waste, no particulates, or smog.
There is, however, no free lunch. The solar panels take energy to build and the power generated depends upon the sun. At night, no power, during cloudy days the amount of power generated is greatly reduced.
To solve that issue, some form of backup, or power storage is needed.
The most practical method for most is to have a "grid tied" system. This way, you use your own solar when it is producing power, and the electrical grid when you are using more energy than your panels are providing.
When your panels are providing more power than you are using, that energy goes back into the grid. In Minnesota, utilities pay you for any excess energy you send to the grid.
You can also use a generator, or battery backup.
There are a number of other options which people have used, the above are simply some of the more common methods.
How can I get some panels?
The most common methods of taking advantage of solar panels is to either buy, or lease them.
Buying them can be thought of as buying 25 years worth of power for the cost of 10-15 years of power bills all at one time.
This can be as little as 7-8 years (I've even seen 6) depending upon local incentives for solar panels.
Also, if the cost of electricity goes up faster than expected the payback will be shorter still.
Leasing solar panels is another good option for many people, although not all areas have this as an option.
The way this typically works is a company that installs solar panels, such as Solar City, will install the panels on your roof.
You pay a monthly fee to Solar City. That monthly fee should be less than the amount you save on your electric bill due to the panels (if not, don't lease, it isn't a good deal;)).
Check with your local solar installers to see if this is an option in your area. Out in California this is quite common. Last I checked this has been very slow to catch on on Minnesota.
Recently in Minnesota, Community Solar Gardens have started being built.
The way a Solar Garden works is a large group of solar panels are set up at an appropriate area. Individuals who don't have a good location for panels can then lease panels. The power generated by the panels is then deducted from their power usage.
The specifics depend upon the utility and company or group that installed the Solar Garden.
It may have been the utility itself, or a business, or group of neighbors.
A good resource for more information from a Minnesota company is at Community Solar..
I will be continue to update how well our plan is working in my Blog.
Our home will be powered solely by electricity.
We have no natural gas appliances, we don't even have natural gas lines running to the house.
Solar Benefits
The amount of solar energy falling onto the surface of our parking lots, residential roofs, commercial and industrial rooftops, etc. is truly amazing.
Basically you could generate as much energy as the world uses with enough solar panels to cover an area a bit larger than the state of West Virginia (see this link for details).
So in addition to the fuel being free, the fuel also never spills. O.K. technically it does, but when there is a solar panel spill we call it a "nice day"!
There is no waste product from the fuel. No coal ash storage pits, no nuclear waste, no particulates, or smog.
There is, however, no free lunch. The solar panels take energy to build and the power generated depends upon the sun. At night, no power, during cloudy days the amount of power generated is greatly reduced.
To solve that issue, some form of backup, or power storage is needed.
The most practical method for most is to have a "grid tied" system. This way, you use your own solar when it is producing power, and the electrical grid when you are using more energy than your panels are providing.
When your panels are providing more power than you are using, that energy goes back into the grid. In Minnesota, utilities pay you for any excess energy you send to the grid.
You can also use a generator, or battery backup.
There are a number of other options which people have used, the above are simply some of the more common methods.
How can I get some panels?
The most common methods of taking advantage of solar panels is to either buy, or lease them.
Buying them can be thought of as buying 25 years worth of power for the cost of 10-15 years of power bills all at one time.
This can be as little as 7-8 years (I've even seen 6) depending upon local incentives for solar panels.
Also, if the cost of electricity goes up faster than expected the payback will be shorter still.
Leasing solar panels is another good option for many people, although not all areas have this as an option.
The way this typically works is a company that installs solar panels, such as Solar City, will install the panels on your roof.
You pay a monthly fee to Solar City. That monthly fee should be less than the amount you save on your electric bill due to the panels (if not, don't lease, it isn't a good deal;)).
Check with your local solar installers to see if this is an option in your area. Out in California this is quite common. Last I checked this has been very slow to catch on on Minnesota.
Recently in Minnesota, Community Solar Gardens have started being built.
The way a Solar Garden works is a large group of solar panels are set up at an appropriate area. Individuals who don't have a good location for panels can then lease panels. The power generated by the panels is then deducted from their power usage.
The specifics depend upon the utility and company or group that installed the Solar Garden.
It may have been the utility itself, or a business, or group of neighbors.
A good resource for more information from a Minnesota company is at Community Solar..
Appliances
According to the U.S. Energy Information Administration, in the typical household in 2009, over 36% of the energy was used in lights and appliances.
Finding energy efficient appliances are a great way to keep your energy use down.
We plan to use 100% LED lighting in the house. All of our appliances are Energy Star appliances. Many greatly surpass the requirements for Energy Star.
Finding energy efficient appliances are a great way to keep your energy use down.
We plan to use 100% LED lighting in the house. All of our appliances are Energy Star appliances. Many greatly surpass the requirements for Energy Star.
Driving on sunshine!
We love driving electric!
The added convenience of waking up every morning with a full "tank" is wonderful. The quality of the drive and performance are amazing!
Our home is designed to produce as much solar energy the house AND two electric cars use annually. We calculated the energy needed using 24,000 miles for both cars combined. This is about 8,000 fewer miles than we used to drive.
The majority of those savings is because we are now 15 miles closer to the center of the metro region. This means most days that we drive somewhere, we will take 20-30 miles off the round trip.
Transportation by car takes a lot of energy. Each gallon of gas has as much raw energy in it as 33.7kWh.
The average car (25mpg) that drives 12,000 miles per year, uses about 480 gallons of gas.
That is the equivalent of 15,840 kWh for one car, or 31,680 kWh for two!
An electric car typically can drive 25 miles on about 9 kWh (more efficient electric cars are closer to 8 kWh), making it over three (almost four) times as efficient.
To drive two electric cars the same 24,000 miles would take about 8,640 kWh.
We never could have afforded, or had space for enough solar panels to produce 31,680 kWh.
While 8640 kWh is still a lot of power, it is much more manageable.
The added convenience of waking up every morning with a full "tank" is wonderful. The quality of the drive and performance are amazing!
Our home is designed to produce as much solar energy the house AND two electric cars use annually. We calculated the energy needed using 24,000 miles for both cars combined. This is about 8,000 fewer miles than we used to drive.
The majority of those savings is because we are now 15 miles closer to the center of the metro region. This means most days that we drive somewhere, we will take 20-30 miles off the round trip.
Transportation by car takes a lot of energy. Each gallon of gas has as much raw energy in it as 33.7kWh.
The average car (25mpg) that drives 12,000 miles per year, uses about 480 gallons of gas.
That is the equivalent of 15,840 kWh for one car, or 31,680 kWh for two!
An electric car typically can drive 25 miles on about 9 kWh (more efficient electric cars are closer to 8 kWh), making it over three (almost four) times as efficient.
To drive two electric cars the same 24,000 miles would take about 8,640 kWh.
We never could have afforded, or had space for enough solar panels to produce 31,680 kWh.
While 8640 kWh is still a lot of power, it is much more manageable.