Energy Wiseguy

Willie Delfs
Energy Wiseguy Willie Delfs of Able Home Builders

Dear fellow Energy Wise Enthusiasts,
I hope that the content has value to you either as a builder or consumer.  Additionally, I hope that it can help you with your bottom line.  I value your input regarding any of the subjects that I address.  If there is something that you would like highlighted, I would be happy to research and report the subject.  This column will always be a work in progress.  You may contact me at
Your Energy Wise Guy…..Willie


According to research from the National Association of Home Builders (NAHB), nearly half of home buyers are willing to invest $5,000 or more to save $1,000 annually on their utility bills, and 35% are willing to spend upwards of $10,000. But do prospective home owners know what an energy-efficient home is and the terminology surrounding the building practices and features they are looking for?

There are three categories of energy efficiency home owners should be aware of based on their current needs and interests:

Energy-Efficient Home

A home that uses less energy than a traditional home without compromising service to owners and occupants. Home owners can achieve energy efficiency through improved thermal envelopes, solar-oriented construction, low-e windows and efficient appliances. Learn the efficiency of your home now and ways to improve it with ENERGY STAR’s Home Energy Yardstick.

Net Zero-Energy Home

A home that produces as much energy as it uses. The energy produced by the home must meet the household’s needs. Rooftop solar panels are perhaps the most common way for homes to produce energy. This is often achieved through renewable energy such as solar panels. To achieve net-zero energy, the home should be designed using a holistic approach that strives for efficiency and reduces energy consumption without sacrificing service or comfort.

Net Zero-Energy-Ready Home

A home that is outfitted with the necessary structural and technological support to install energy-producing technologies in the future. Net zero energy-ready homes are appropriate for home owners who would like the option to install energy-producing technology in the future. There is also a Department of Energy (DOE) program that partners with builders and offers those professionals who build to specific requirements around energy savings, comfort, health, and durability — Zero-Energy-Ready Home.

Net Positive-Energy Home

A home that produces more energy than it needs. A home owner may receive credit from their utility company for excess energy returned to the grid. It is energy either produced by specific technologies or saved through energy-efficiency measures.

Home owners can get a general sense of how energy efficient their home might be using the following rating systems:

Home Energy Score (HES)

A score of 1-10 is given to a home based on its energy use, with 10 being the most efficient. As with a miles-per-gallon rating for a car, the HES is based on a standard assessment of energy-related assets to allow for easy comparisons across homes in the housing market. This is a DOE program often used for existing homes.

Home Energy Rating System (HERS) Index

A score of 0-100 is given to a home based on an energy audit and report, with 100 being the least energy efficient. The scoring system compares your home to a home built to code in 2006, which is known as the reference home. The reference home would score a 100 on the HERS index, whereas a newer home or one built to a green standard might score a 60. This is a Residential Energy Services Network (RESNET) program often used for new homes. To learn more, visit

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