HERS Rating (Home Energy Rating System)
A HERS rating provides a standard measurement of a home's energy efficiency. Ratings are used for both new and existing homes. In new homes ratings often verify energy performance for the ENERGY STAR homes program, LEED for Homes compliance, energy efficient mortgages, and energy code compliance. Homeowners who want to upgrade the home's energy efficiency can use the HERS rating to evaluate and pinpoint specific, cost-effective improvements. For existing homes, homeowners can receive a report listing cost-effective options for improving the home's energy rating. A HERS rating allows a homebuyer to easily compare the energy performance of the homes being considered and should be included in the MLS listing.
There are two types of ratings:
- Projected ratings - Ratings performed prior to the construction of a new home or prior to the installation of energy improvements to an existing home.
- Confirmed ratings - Ratings completed using data gathered from an on-site inspection, which could include performance testing of the home.
Aspen Thermo Consulting will analyze the home to identify its energy characteristics, such as insulation levels, window efficiency, wall-to-window ratios, the heating and cooling system efficiency, the solar orientation of the home, and the water heating system. Performance testing, including a blower door test for building envelope air leakage and a duct blaster for duct leakage is utilized during the rating.
The data gathered by Aspen Thermo is entered into a RESNET accredited computer program and translated into a rating score. The home receives a score between 1 and 150+, depending on its relative efficiency. The home's energy rating is also equated to a Star rating ranging from one star for a very inefficient home to five stars for a highly efficient home. Other reports included in the energy analysis are:
Action Report - Ranks the building elements based on the relative energy consumption
Air Leakage Report - Lists leakage rates in building envelope and ducts. Also displays the building ventilation information.
Component Consumption Summary - Presents the heating and cooling energy consumption of the building on a component basis such as windows or above grade walls.
Fuel Summary - Summarizes the end-use energy consumption by fuel type.
Energy Cost and Feature Report - Summarizes the annual heating, cooling, water heating, light and appliance costs and the major energy design features of the home.
Lights and Appliance Summary - Summarizes all the annual light and appliance costs of the home.
Emissions Report - Summarizes the absolute values for Carbon Dioxide, Sulfur Dioxide and Nitrous Oxide emissions of the building.
Unlike an energy audit a HERS rating is a recognized tool in the mortgage industry for Energy Efficient Mortgages (EEMs). HERS ratings can also be used in a variety of ways in the housing industry including the compliance with the International Energy Conservation Code, EnergyStar and other standards. The star and the rating score provide an easily understandable means to compare more efficient homes by their relative energy efficiency.
