If you’ve read “super insulated” and “passive house” with Mottram Architecture and you think “Yeah, maybe that’s for me” but you think “I could do just a little bit better” then maybe Net Zero is for you?
Similar to super insulated homes and passive house homes, a Net Zero home with Mottram Architecture is going to have similar principles and expand on those to achieve Net Zero. What we, at Mottram Architecture, deem Net Zero: The home produces all the energy on site that it needs to operate each year. There are complicated metrics about homes that are connected to the grid vs off grid homes. If you choose to participate in a Net Zero program we will help you achieve all the requirements of that program. If you want to be Net Zero without a program we are going to help you produce more energy than you use at the end of the year. It may mean that you produce more in the summer and feed back into the grid, pulling electricity from the grid in the winter months. Or, it may mean that your solar array produces enough energy year-round to be off the grid entirely. These are the principles that we use to develop our Net Zero Homes in Maine:
- First we will visit the site and help to place the home for optimal solar exposure. Whereas in Passive House and Super Insulated structures, it’s good to face south, in a Net Zero home it’s imperative. Although you could do a ground mounted solar system or maybe you have access to wind power, the best and most viable solution to Net Zero construction is the ability to produce power directly at the source.
- Second, after orientation is determine we will maximize the building envelope. With Mottram Architecture you will see R-38-40 dense packed cellulose walls. Walls are either double stud walls or stud/i-joist combos. Ceilings are R-60 loose blown cellulose or R-60 dense packed vaulted ceilings.
- All structures will have one continuous air barrier. This is achieved with a number of tapes, skins, vapor barriers that are all connected together to reduce air infiltration through the building components to increase durability and through the building envelope to reduce heat loss. The continuous air barrier also reduces drafts which decrease occupant comfort. It’s no wonder that we only own our homes for 7 years in the US before we trade up for newer, bigger, prettier, only to not understand why we don’t continue to love our spaces. If you’ve ever been through a Net Zero home, you may start to understand that it’s not just how beautiful the space is, but how comfortable it is to be in, how does the sunlight lift our moods, and where are all the components that make the home truly unique for you and your family.
- Healthy Indoor Air Quality – In order to really achieve a Net Zero home it’s important to reduce air infiltration. Any energy that needs to be used to keep a home comfortable just increases the size of the solar array which increases the budget. At some point it will become cost prohibitive. So a concentration on reduction of the thermal envelope and the air infiltration means you need to pay attention to the air quality within the space. Heat recovery in Net Zero homes in essential in reducing the demand. Everything in Net Zero is a balancing act. You need to provide fresh air and run the fans that provide the fresh air, but reducing infiltration reduces the heating system which also needs to be run by the solar system.
- High R-Value/Low Infiltration windows. As we mentioned above, everything comes down to demand. The higher performance the windows are, the less energy you need to make with your solar system. That being said, it’s not impossible to achieve Net Zero with double pane windows, it just requires more energy. Triple pane windows improve the occupant comfort because the interior surface temperature of the window is higher and the construction allows them to seal tighter and let less air through. But most important with windows is the right type and operating style. A fixed window will have the least air infiltration, followed by casement, double hung, awning and hopper, and last sliders. If you can reduce the number of windows you need, place them in the right locations, only have operating sections where needed you can make a huge impact on the performance of your building and reduction of energy demand on the solar system.
- Heating system. With Mottram Architecture we are 90% likely to recommend a heat pump for our Net Zero homes. First, when we talk about Net Zero we talk about our ability to produce all the energy on site that we need to operate the home. The most effective way to create energy on site is electricity. Secondly, electricity has no fossil fuel off-gassing that can be trapped in a super tight home and cause serious harm to occupants. Third, heat pumps are significantly more efficient than standard electric heat. Depending on the configuration of the home will depend on whether it requires a ducted or mini-spilt system.
- Efficient water heating technology – typically this can be a hybrid heat pump hot water tank if you have an unfinished basement or garage. If you are building a home on a slab, more likely you will have an all electric tank or a solar thermal system with electric back up. If you are a home that uses gas, we may have an on demand modulating condensing boiler that would produce your hot water. As we mentioned before, gas is not a renewable resource and it can get tricky offsetting the use of fossil fuels in a Net Zero home.
- Renewable power production: To truly be Net Zero we believe a home should produce more power on site than it consumes during the year. On site produced energy is most efficient when it is directly attached to the structure which is using the energy. In Maine that means solar. By following all the principles above we can reduce consumption of the home to a manageable amount of energy use that can be produced by a solar array. Most people are not interested in being off the grid, so a grid tied solar system which produces more energy in the summer and pulls from the grid in the winter is the most cost effective solution. This allows you to put a smaller solar system on your home since you can achieve peak demand in the summer and count your credits for over production towards your winter months. If you size a solar system to be completely off the grid it will need to meet peak winter demands and will significantly over produce in the summer months. The risk with completely off the grid systems is that we have yet to figure out how to control the weather! If we have a cloudy month with snowfall and covered panels you may need to seriously watch your electric consumption and make trade offs so you do not run out of power. This is where you may need to forgo making coffee, watching tv, or even in severe cases, taking showers. Therefore, most customers choose to stay tied to the grid to safely enjoy creature comforts.
If you love all the ideas of the principles we mentioned above, then this is how you move forward with Mottram Architecture on building your Net Zero dream home!
Answer these questions:
We don’t require any information for you to reach out to us about your project. But during our first phone or email conversation we will ask you the following questions, so it will help if you have thought about these before you contact us.
- What are you looking for?
- Why do you want this?
- On a scale of 0-100 how motivated are you to finish the project?
- What is your budget for this project? Or do you need help determining what your budget should be?
- When do you want this project to be complete?
- Apart from you, who else is involved in the decision making process?
- Let us know you’re interested in Zero Energy Homes
Once you’ve answered the questions, give us a call. We do an initial 1HR consultation at no cost to you. It’s a great way for us to introduce ourselves, go into more detail on who we are and how we work, and find out your project budget, scope, schedule and really what you need from us.
After our first introductory meeting, we will put together a proposal for you on what it will be like (and cost) to work with Mottram Architecture based specifically on your project.