Zero Energy Homes help home owners pare energy use and cut costs but getting to that point requires following forward-thinking experts’ check list.
You can cherry pick materials and systems to curtail energy use in a residential and multifamily home and building. But constructing the entire envelope to bring costs down to zero requires a more intensive design and construction process. Originally dubbed Zero Net Energy Homes, the genre was rebranded by the U.S. Department of Energy without the “Net.” The goal remains similar. Despite these types of structures being built around the globe, there’s still confusion about how to achieve best results. Several experienced architects and energy efficient proponents shared these points seven more ideas to heed:
1. Pick an energy-efficient heating and cooling system. Also referred to as an air source heat pump, the best choice works in each season to move air in the right direction. In summer, it takes heat from inside the house and sends it outside, and in winter it takes cold air that comes in and heats it. Buy the most efficient one according to industry HSPF (heating seasonal performance factor) and SEER (seasonal energy efficiency ratio) standards. Note: HSPF or heating seasonal performance factor is a term used in the heating and cooling industry to measure an air source heat pump’s efficiency. https://www.energystar.gov/products/heating_cooling/heat_pumps_air_source/key_product_criteria SEER or seasonal energy efficiency ratio standards offer another important measurement for the efficiency of air conditioners. https://energy.gov/energysaver/central-air-conditioning
2. Include an energy-efficient, fresh air supply. While a tight house is the goal, a sealed box causes its own set of problems—the absence of fresh air, which can be unhealthy. The solution is to include an energy-efficient ventilation system, known as ERV for Energy Recovery Ventilation. This system exchanges and treats incoming air by cooling and dehumidifying it in warm weather and preheating and humidifying it in cool weather. “We like to say in the industry, ‘build it tight and ventilate it right,’ which some of the earliest Zero Energy Homes didn’t do,” says Ryan Shanahan, a senior green building consultant with Earth Advantage in Portland, Oregon, which certifies green-built homes and multifamily dwellings. Besides eliminating energy use, it will help improve air quality by paring moisture that can lead to mold, increased asthma problems, and other health issues. Do more by picking no- or low-VOC (volatile organic compounds) paints, adhesives, sealants.
3. Select energy-efficient appliances and lighting. Making these kinds of smart choices has become more common, even for more traditionally constructed homes. Look for the EnergyStar label. Even appliances that once were considered energy guzzlers like dryers have been redesigned to save energy. Lighting can also play a huge part in reducing energy use. New federal standards require lighting manufacturers to sell bulbs that meet minimum efficiency standards, and the most efficient are LEDs. These have come down in price, had their color temperatures or light quality improved, don’t include mercury, and are dimmable, says Shanahan. In some communities, LEDs are given away, as Joe Emerson has found. Emerson is a homeowner in Bend, Oregon, who built his first Zero Energy Home in 2012, and has followed up with several others. He also writes about the topic at Zero Energy Project. Boston architect Joseph Kennard also suggests home owners be thoughtful about the number of appliances and lighting fixtures they add into any single home since they end up not using all—perhaps, they should do without a microwave they would rarely use for a steam oven, or give up a second wall oven. The same restraint can apply to lights.
4. Factor in up-to-date on incentives and tax credits. Many home owners remain concerned that a Zero Energy Home will cost more at the front end. Industry experts like Shanahan put the additional cost for a passive solar house at 5 to 10 percent higher than a comparable sized less efficient design. But costs can be pared from the start by using incentives and tax credits, which are still available in many areas for solar PV panels, solar hot water tanks, and energy-efficient appliances. The extra dollars can be wrapped into a mortgage since more “green” financing options are available. For information, see the Department of Energy’s Database of State Incentives for Renewables and Efficiency. Kennard, who says many incentives and credits are still available in Massachusetts, likes to show clients how the savings can curtail their costs and lead to more breaks at the state level.
5. Go ready- or off-the-shelf rather than custom made. Home owners and their pros don’t have to re-invent the wheel, so to speak. More companies are developing house plans that you can use as is or tweak. Builder and designer Ted Clifton founded Zero Energy Plans to offer plans that range in price according to square footage. The plans list specifications for different climates. Facades veer toward the traditional but a few are modern, which has become more popular, Clifton says. “But be cautious,” says Kennard, who believes it’s important to engage experts who have been working on such projects for a while and who know what to pick and how to combine systems so they work for the long term. “You don’t want to deal with water and mold issues down the road when you have tight buildings. You need proper air exchanges for good balance,” he says.
6. Get ahead of the pack. More communities, cities, and states are studying the advantages of initiating Zero Energy requirements. California has passed a law that requires all new construction to be Zero or near Zero by 2020. “Why not help build a house of the future rather than an outmoded house?” says Emerson. Your clients already are able to have their houses certified for a relatively low cost, often even less than 1 percent of the budget, says Shanahan. Earth Advantage offers several certifications, from LEED for homes to EnergyStar, and Passive House PHIUS+, the latter a passive house certification that represents the most efficient energy standard worldwide.
7. Consider valuable aesthetics, too. There’s no reason that high efficiency should shortchange looks. “I wanted my project on Allandale Street to be aesthetically beautiful; why I felt a contemporary exterior was best,” says Jacqueline Nunez, a Boston developer with WonderGroup, who has planned her Allandale Street project to feature 20 town homes and condos in Boston. Kennard, too, favors contemporary designs, and his current project features anodized painted metal standing seam siding and roofing; a less costly option would be cement board siding with asphalt roof shingles, he says.
Bottom line: In pursuing this niche, home owners benefit the overall built environment and gain a house that offers a high degree of comfort, healthful air quality, more quiet due to its tighter package, lower energy costs, and greater resilience so the house can cope better all the time and especially during a power outage. And more good news is that more home owners are considering these types of choices, Kennard says.