What is the Net Zero Energy Home Design Process?
Creating a Home Design: Net zero energy home designs begin with a dialogue between the client, designer, and builder. At first introduction, prospective clients often bring sketches, pictures, and a wish list with them. An experienced builder is able to clarify a client’s ideas and offer plans or suggestions based on past experience. For example, if accessibility is important to the client, the builder might suggest floor plans that include a large first floor with master bedroom, with a smaller second floor designed for guests.
Identify Essential Spaces: A second step involves recognizing and labeling the essential living spaces. A home offering maximum efficiency reduces the amount of un-lived-in space, such as under-eave storage areas, breezeways, higher ceilings and unfinished basements. By recognizing these spaces as optional, the builder and client can work to maximize useable space.
Line-Item Essential Options: A third step is to identify non-essential options that can significantly increase both cost and energy use in a home, such as fireplaces, decorative woodwork, saunas, whirlpool baths, walk-in closets, and larger windows. A client may choose to add some of these later, but keeping these as separate budget items will allow the builder and client to focus primarily on controlling the overall energy use and base price of the home.
Recognize True Costs of Infrastructure: Most homeowners today are not satisfied with standard code electrical wiring. Whether you want a man cave, under-cabinet lights, tray ceilings, heated towel bars, recessed lights, or landscaping lights, you will want to identify with the builder the real costs of these features and keep them separated from the baseline budget. Experienced builders will assist you with deciding which options matter most. For example, you may decide to invest in radiant heating to melt snow and ice on your roof, driveways, and walkways because that will make your home safer as you get older. On the other hand, you may decide that a full-house vacuum isn’t really necessary.
Consider Low Maintenance Options: A net zero builder might encourage you to consider the cost of maintenance in your deliberation. For instance, wood is often considered to be the highest quality material for the outside of a home. However, vinyl siding is not only cheaper to install, it offers excellent insulation and lower installation costs and because it requires no painting, it is easy to maintain.
Common Misperceptions of Net Zero
Because net zero homes are high-performance homes, they cost a little more to build. Yet the additional up-front cost can provide a return that begins as soon as you flip on the power switch. And the return continues to pay you back as long as you live in the home. Aside from initial cost, it’s difficult to discern any other real objection to choosing net zero over conventional construction. However, net zero is a newer concept and open to misperceptions, such as:
A net zero home design is typically smaller than that found in conventional home construction. A net zero home can be built in any size you chose. As with any conventional home, HVAC (heating, ventilating, and air conditioning) systems need to be sized to match the needs of the home, but there are no limitations to size. In fact some very large and prominent commercial buildings have achieved net zero energy.
A net zero home looks odd. A decade ago, solar panels lining a roof might have seemed unusual, but installations today are quite common and are likely to become more so in the future. Ironically, in the not too distant future, a new house that does not integrate solar energy into its design may be considered the odd home on the street.
Net zero homes are stuffy because they’re too tight. Yes, these homes are tight. This contributes to the home’s energy efficiency. It’s also why net zero homes are always equipped with an air exchange system that introduces tempered fresh air while minimizing heat loss. With such systems in place, net zero homes provide a healthier indoor environment than exists in conventionally-constructed homes.
Net zero homes can’t keep up with heating demands in below-zero weather. Many net zero/high performance homes have a backup system (usually electric or gas) to carry the home through any short stretch of extreme cold conditions. Experience shows that these systems get very little use (regardless of prevailing sub-zero temperatures). Fact is, a net zero home is so well insulated, the home is unlikely to know just how cold it is outdoors!
FYI: All heating and cooling mechanical systems are designed to satisfy the needs of “minimal energy code compliant” homes, including the ones used in net zero construction. Although we calculate much lower heating and cooling loads for a net zero home, we use the same geothermal and cold climate heat pumps, which only come on ‘when asked’. Net zero homes rarely ‘ask’ cold climate heat pumps to operate because the homes are so airtight and well-insulated, and retain interior temperatures so much longer than a minimal code-compliant home. So, a net zero home wouldn’t necessarily know that the outdoor temperatures have dipped frighteningly low for some time period.