Background information on HERS

The California Energy Commission (CEC) was established in the late 1970’s.  One of the missions of the CEC was the creation of building 4energy standards for newly constructed homes and commercial buildings.

The Building Energy Standards, commonly referred to as Title-24 (or T-24), ensure that newly constructed homes and commercial buildings in California are among the most efficient in the US if not the world.  But what about existing homes?

In 2007 approximately 112,000 new homes were built in California.  There are ~13.2 million occupied housing units in California.  Comparing these two numbers makes it easy to understand why we must deal with existing homes as well as newly constructed homes if we want to truly address residential energy efficiency.

Energy Efficient Mortgage (EEM)

Energy-efficient homes cost less to own than non-efficient homes, even though the energy efficiency improvements may add to the cost of the home.  An EEM allows the purchaser of a home to make energy efficiency improvements to the home and add the cost of these improvements to the mortgage.  The following example shows how and EEM can be advantageous.

     EEM Example:

                                              Existing Home no improvement         Same  home w/improvement

Home Price                                                       $150,000.00                                 $150,000.00

Energy Efficiency Improvements                          $ 0.00                                          $  4,816.00

Loan amount(90% mortgage)                             $135,000.00                                 $139,334.00

Monthly payment (6% interest)                            $  991.00                                      $1,023.00

Energy Bills (per month)                                      $  186.00                                         $93.00

True monthly cost of ownership                           $1,177.00                                     $1116.00

Monthly Savings                                                                                                  $61.00 per month