Expert guidance from energy specialists. Home Energy Rating Systems (HERS) Raters help you tap into energy-efficient home certifications, high-efficiency equipment, high-performance building practices and the latest material options.
Zero Energy Challenges
The Connecticut building code requires that all new homes meet a minimum level of energy efficiency. Most new home buyers expect more than this minimum and some new home builders claim their homes are energy efficient. Without an objective, third-party measurement of energy efficiency there is no way for homebuyers to make informed decisions.
A Home Energy Rating (HER) solves this problem by assigning a numerical rating, called the HERS Index, to a home. The HERS index is the industry standard used to measure the energy efficiency of a newly constructed home. It’s also the nationally recognized system for inspecting, calculating and estimating a home’s energy performance.
HERS ratings are determined by trained Home Energy Raters who are certified by RESNET (Resnet.us), a national, non-profit organization that oversees the standards for Rater certification, quality assurance and the calculation of home energy ratings.
Certified HERS Raters use energy modeling software to determine the home’s HERS Index. The energy models use information collected by the Rater from on-site inspections of the home during construction, from testing the air-sealing of the building and its duct systems, from building plans and from independent reports of the efficiency of the installed heating, cooling, water heating, ventilation and on-site generation systems.
In Conneticut there are almost two dozen companies that provide HERs ratings throughout the state - most are listed on our Find a Contractor
A Home Energy Rating (HER) assigns a numerical rating to a home. - called the HERS Index.
The HERS index
This nationally recognized system for inspecting, calculating and estimating a home’s energy performance, is the industry standard for measuring the energy efficiency of a newly constructed home.
The HERS index is determined by the Home Energy Rater, who assesses the energy efficiency of a home, assigning it a relative performance score. The lower the score, the more efficient the home or dwelling unit. A typical resale home scores around 130 on the HERS index (on average), while a standard home, built to energy code, scores around 100. Every point below 100 on the HERS index, translates to roughly 1% energy savings compared to a code built home.
The scale to the right shows the range of HERS indexes you might encounter when buying a home. Older, less efficient homes have HERS Indexes over 100. The US Department of Energy estimates that a typical resale home has a HERS index of about 130. Some drafty, poorly insulated homes may have indexes as high as 200! Newer or energy-retrofitted homes have indexes under 100.
Connecticut New Construction
All new Connecticut homes should have a HERS Index below 100 since the State adopted higher energy efficiency standards in 2011. A home built to the current building code standard should have a HERS Index close to 85. However many new homes are built to be much more energy efficient and achieve HERS Indexes below 60.
Zero Energy Homes
Homes that produce as much energy as they use by combining high-performance insulation and mechanical systems with renewable energy systems, can achieve HERS Indexes close to zero. The CT Zero Energy Challenge is all about encouraging local builders, architects and homeowners to build near zero - or even zero - energy homes.
Additional information about HERS can be found at the Residential Energy Services Network (RESNET). Their interactive HERs Index model shows the impact on savings, carbon footprint and comfort from building to more energy efficient standards.