HERS Index Ratings
The structure has to meet a certain efficiency level based on the individual components in order to meet code. The performance method allows components to be combined together allowing for some items, such as air conditioners, to have higher efficiency ratings while other items, such as windows, are not rated as highly. The combination of the higher and lower rated items still allows the house to meet the energy code and be constructed.
There also exists a prescriptive measure that demands all components meet a minimum efficiency level which meets the standards of the Energy Code and that no component can be less efficient and be helped by the efficiency of another component. Depending on the project, you may want to meet the performance method or you may choose to use the prescriptive method. We will show the differences so financial aspects can be taken into account and allow for an informed decision to be made as to which path to compliance will be followed.