California Association of Building Energy Consultants

Adding To or Altering Your Home?

If you are adding even one square foot of new space to an existing home, it is considered an addition to your home and triggers energy code compliance. Changing windows in an existing home is just one example of an alteration to a home that triggers energy code compliance. Fortunately there are many avenues for meeting the requirements of the current energy code.

One is to meet the current code requirements as a new home would. This is a difficult process because normally the additional square footage or alteration is small and in general a good deal of new windows are installed. Also there are not a lot of upgraded energy features to choose from in a small addition or alteration to model to help meet the code.

Another method (using a California Energy Commission approved computer software program) involves modeling the existing home with all of its energy features, removing any walls, windows and other item(s) that will change with the addition of the new square footage, and improving on at least two energy measures in the existing home. For example, changing out an existing HVAC system, or water heater or windows. The next step is to include the new square footage of the addition and all of the new energy features. The program will calculate the energy use of the existing home before the addition/alteration and then the energy use of the home after the addition/alteration. The goal is to prove that the home will not use any more energy than the existing home before the addition/alteration. This process is less strict than meeting the current energy code for new homes. Compliance margins are easier met with affordable energy requirements.

This is an involved process and requires the expertise of someone who clearly understands the energy code and the software program's capabilities. A certified energy analyst is your best choice.

As always, I am available to discuss the process of meeting the California Energy Code for any building project. Contact me …