It is probably no accident that the Net Zero community has come up with a 12-step program to help builders and owners get off their dependence on cheap energy.
Building a home or a commercial building to Net Zero is not that difficult. Net Zero means a building that only uses as much energy as it can produce on an annual basis. Not many locations where people build are going to have access to wind, water, or wave energy production, which means that the building will be using solar energy. Typically, solar panels will be on the roof, so the building’s energy consumption cannot be greater than the number of panels that can be mounted there. Structural Panels are the perfect building envelope solution for Net-Zero building.
When attempting to balance the available surface area to the amount of energy needed, the only variable is the building usage. We can break that variable down into two parts:
The occupants and their lifestyle.
Since we have found we cannot change the way people live, let’s focus on the building – where the 12 steps come into play. Let’s take them one at a time.
1. Start with a “Smart Design.” This statement means a lot of different things to folks, but let’s say – don’t build any more than you need. Despite what your realtor tells you, if you only need two bedrooms and one bath, don’t build a 4-bedroom 4-bath house. A compact structure is more efficient than a sprawling home. A single-story is better than two. (Resource: Sara Susanka’s “The Not So Big House”)
2. If possible, orient the home on an east-west axis so the building and its occupants can enjoy the benefits of sunshine during the winter. If changing the orientation is impossible, do the best you can.
3. Optimize your design with energy modeling. What if you put a larger window south, or move a window on the west to the north? You will be surprised at what even little changes can accomplish.
4. Super insulate the building envelope. There are lots of ways to achieve this one. After 30 years of helping clients build energy-efficient homes, I can tell you there are easy and hard ways. Structural insulated panels (SIPs) make it easy. A 6″ wall panel can reach R-28 and an 8″ up to R-36. And while we’re talking about insulation, note that lumber isn’t very good at only R-1 per inch. To reduce the thermal bridging by taking at least half of the lumber out of the wall system. Using insulated headers where needed helps make a better building.
5. Super air seal the building. Infiltration rates of 1ACH @ 50 pascals are easy to obtain with SIP Panels, without days of going back, trying to find that pesky leak.
6. Think about the windows. They are a huge drain on the energy efficiency of the walls. People do like them, though. Put them on the correct elevation and in a reasonable size. Once you do that, you can afford to put the good ones in the holes. The right window today can get you close to an R-4.
7. Ventilate properly. Ventilation is essential now that we have taken all the leakage out of the building’s enclosure. Where you live makes a difference in how you decide to approach this challenge. Everything from a smart bath fan to an elaborate air-to-air heat exchanger is possible.
8. Choose high-performance heating and cooling. This choice is easier now that we have cut the energy use by 50% or more. My favorite is still a mini-split (ductless) heat pump. I like these pumps because they serve both needs with a compact unit. They allow zoning in different rooms, and they have the highest efficiency of most HVAC systems.
9. Heat water effectively. Getting water hot becomes one of the highest consumers of energy now that we have contained the other hogs. In today’s environment, we are quickly using up natural gas as a transitional fuel. To that end, the heat pump water heater is a good choice. The market has matured around this product, but you must be careful where you put the unit as it produces cool air as a byproduct of the heat pump cycle. Look at units that are split, with outdoor and indoor components, unlike the more common combined models.
10. Choose the right appliances. You’ll need to do your research, but EnergyStar© can guide you to the most energy-efficient products.
11. Think about lighting. Choose both room and task lighting with care. Does the kitchen need twenty can lights? Perhaps a couple of lights so you can find your way when raiding the fridge at midnight, and some well-placed task lights for cooking and over the sink would do the trick.
12. Consider plug loads. Think about computer and battery charging. A few lamps round out all the items for conserving energy.
Now you can have your renewable energy reward. If you have worked hard on this list, the number of solar panels you can fit on your roof will equal the amount of energy you need to live a comfortable and sustainable life.
If you’d like to know more about SIPs construction, contact the PBS Rep in your region.