Paths to Net Zero

There’s more than one way to reach the goal of building Zero Energy homes. A new EEBA training helps builders chart their best course.

As more high-performance zero-energy ready homes get built, and as more customers learn the financial benefits of owning such a home, demand for them will continue to rise. But for builders who have never exceeded minimum code requirements, the prospect of building to zero can seem daunting.

Those preparing to embark on the journey usually have a lot of questions. What features should they start with? How long will it take to master this way of building? How will my customers pay the extra upfront costs?

The answers to the first two questions, according to Bruce Sullivan, who teaches EEBA’s new Path to Zero Energy Homes training seminar, are 1) you can start almost anywhere, and 2) once you get going you can move along at your own pace. He also says that the path can unfold in a nearly infinite number of ways. In fact, the seminar might better be called “Paths” to Zero, since the journey will be different for every builder.

The path an individual builder takes will depend on an array of factors that include local market demand, climate zone, price range, architectural style, utility rates, and even company culture. “When it comes to Zero Energy there’s no silver bullet,” says Sullivan, who has been involved in high-performance and green building education for more than 37 years and has trained thousands of builders and other industry professionals. “It’s more like silver buckshot because you’re spreading your efforts over a lot of small actions.”

Those who complete this journey with the fewest bumps, detours, and dead-ends are those who have a customized map to follow. EEBA’s training teaches how to create such a map.

Charting the Course

In the Path to Zero seminar, EEBA presents a 12-step model for drawing such a map. If that sounds like a recovery program for addicts, it’s an apt comparison.

Unhealthy behaviors often begin as responses to short-term anxieties, then end up creating more problems than they initially were intended to solve. What does that have to do with homebuilding? The answer is that conventional production building helps the builder satisfy the typical consumer’s demand for trendy features and affordability–but this may lead to long-term destructive effects on both the environment and the builder’s business, as the market changes. And the ongoing operation and maintenance costs are often more than the homeowner bargained for.

Sullivan presents his map as a more effective way to satisfy demand for affordable housing. “I’m bold enough to say that a zero energy home can be free,” he says, and as an example, points to his own Bend, Ore., home. “The house my wife and I built a few years ago is all-electric, including charging for our electric car, and it still ends up paying us $8 per month.”

He has taken the lessons learned from his home, as well as from other builders and designers, and applied them to the production environment. “In EEBA, we recognize that production builders have special situations,” he says. “They need to create economies of scale, so the options include things that are reproducible and affordable.”

Each of the map’s steps includes an overall goal, a set of design principles and construction details, as well as a menu of equipment and material options to choose from. For instance, nearly all builders understand the benefits of a thermal envelope with high R-value insulation, minimal thermal bridging, and advanced air sealing–but many lack a good system for evaluating the options that will get them there. Will it make more sense to use 2×6 studs and foam sheathing or to frame double 2×4 walls? What are the advantages, disadvantages, and economic consequences of each?

Or take the example of heating. The vast majority of U.S. production builders install gas furnaces with an average efficiency of about 90 percent, but a zero energy home might be better served by a smaller, more efficient unit. If the builder is also the developer, switching to heat pumps might let them eliminate the cost of installing a gas infrastructure in the community.

In each step, you can choose the most cost-effective option or the one that makes the most sense for your homes. The end result will be a home tailored to your climate, your market, your architecture, and your business.

The path to zero energy building is a pyramid with each successive level building on the one below it.

Pyramid Scheme

Having a set of steps is more than most builders have, but the steps will have even more impact if they’re weighted. The Path to Zero training groups these 12 steps into what Sullivan calls the Zero Energy Pyramid. Although you can get on the path anywhere, the Pyramid shows you how to prioritize your actions to get the best returns.

It looks like this:

Design (the base)

1. Start with Smart Design

2. Orient for Sun Tempering

3. Optimize with Energy Modeling

Shell

4.Super-seal the Envelope

5. Super-insulate the Envelope

6. Select Optimum Window Efficiency

Equipment

7. Ensure Clean, Fresh Air

8. Specify High-Performance Heating and Cooling

9. Heat Water Wisely

Plug Loads

10. Select High-Efficiency Lighting

11. Choose Efficient Appliances

Renewables (the capstone)

12. Use Renewable Energy

The Pyramid structure makes an important point. A good thermal envelope will offer the most benefit if it’s part of a well-designed home with solar features optimized for the climate. Likewise, efficient HVAC equipment will only deliver its full value if placed in a well-designed and detailed shell. For instance, Sullivan’s own zero energy home includes a 4.3-kilowatt solar array, but the reason he enjoys a new monthly profit from the electricity it generates is that he started with good design principles then moved up the pyramid.

Learning to Sell

While the path to building a zero energy home is one of design and technology, selling it is a matter of knowing how to present the benefits in a compelling way. The EEBA Path to Zero Energy Homes seminar covers that, as well, and teaches builders how to use various calculators to show homeowners the economic consequences of each choice. “If someone is more concerned about initial cost than ultimate benefit, you need to know how to turn that around,” he says. “You need to show them they will benefit economically the minute they walk in the door.”

The seminar includes detailed information about returns on the investment in zero energy features, the costs of ownership in different parts of the country, and other metrics that can be used to educate homebuyers.

As you would expect, this article barely scratches the surface. Those who want to learn more should check out the new EEBA Path to Zero Energy Homes seminar in-person as more trainings are scheduled around the country. It will also be offered at this year’s EEBA High Performance Home Summit, October 1 – 3 in Denver, along with dozens of other technical sessions and networking opportunities for builders and manufacturers.

This article was reprinted with permission from The Energy & Environmental Building Alliance (EEBA). To read more articles like this, check out the EEBA blog here.