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The Importance of a Home Energy Audit

Do I need an Energy Audit?

One of the premier services offered by our company, and in our opinion the most useful, is the energy audit, or energy assessment. Both mean the same thing, but some utility companies prefer we don’t refer to it as an “audit”. They say it will remind people of the IRS. But to me it’s an energy audit, sorry.

Anyway, if you are thinking of having additional attic insulation added to your home, or maybe you just think you need your floors insulated, or maybe you are building a room addition or a new home, then you likely don’t need an energy audit. In cases like this when you know exactly what you want and it’s just insulation and nothing more then give us a call and we’ll make an appointment to come to your home and take the necessary measurements and put together a proposal for you. If you are building a new structure or you want just a single item an energy audit really isn’t necessary.

Energy Audit Rebate Programs

Most folks are eligible for either of PG&E’s two rebate programs.  One, the EUC (Energy Upgrade California) program, does require an energy audit prior to any work being done.  For the EUC program you only have to do two measures and there is no upper limit on the rebate amount, unlike the Home Upgrade, the other PG&E program, which is maxed at around $3k. Rebate amounts are calculated based on potential savings as listed on the econ2 sheet, the last page of your energy audit, and start at 10% savings.

The other program “Home Upgrade” (administered by BayREN in nine Bay Area Counties) does not require an audit. However one of these programs is a lot more generous than the other if you meet certain guidelines. If you don’t have the energy audit done you have no idea which program is best for you to use. One allows propane use while the other doesn’t.  If you are planning to participate in Home Upgrade, the program where you get a cash rebate based on point values of measures installed, PG&E will tell you an energy audit is not needed. And I suppose they are technically correct. However, if you use the Home Upgrade program you must install a minimum of three measures from the program list. Almost always you will have to select either “duct sealing” or “whole house air sealing” as one of the measures you must do. In order to get your points for these, you must seal the house or the ducts to a certain test-out level. Without the testing provided by an energy audit how will a homeowner or their contractor know whether these levels can be achieved? You need the test results provided by an energy audit before you can know if you can reach the point award level.     

Our Home Audit Process

So there are just a whole lot of reasons to have an energy audit done. At the appointed time, we’ll send our crew out with testing equipment. They will pressure test your HVAC duct system. They can determine if it needs repair, or leaks so much it should be replaced (average duct leakage has been found to be between 25% & 40%). They also test the air infiltration level for the house as a whole using a blower door. An audit also consists of gathering test information but also much info is gathered from observation. We look at your heating and cooling system and using the info from the factory tag we can usually determine its age and efficiency. Any gas fired appliances will also be tested for back drafting and whether there is incomplete combustion or any other dangerous condition occurring. Special attention is paid to the hot water heater for safety and function.  The crew also looks at the insulation levels of your home, walls, floors and attic insulation levels are checked and noted. The type and condition of your windows is recorded along with the azimuth (compass direction) of the front of the house. We also note the amount of old incandescent lighting being used. Gathering this much information can take two technicians about two to three hours depending on house size.

Crunching the Data and Creating Your Report 

All this field data is brought back to our office and organized and then put into a computer program. A model of your home is built inside the computer and populated by an average family. The model house is then subjected to every climatic condition and extreme for every hour of every day for a full year. The computer has these conditions stored in its memory for each climate zone throughout the State.  Scientific testing and observation are used to determine how your home functions under every climatic condition your climate zone has to offer. 

Then various upgrades and improvements are added to the model house, then it is tested again. In the end, when all possible upgrades have been tried, a list of recommended upgrades is then complied. This list is presented in order of each items “cost-effectiveness”. This means the upgrades that will recoup any money invested to install them the soonest will be at the top. If not all items can be afforded then the logical thing is to start at the top of the list and work down. The audit also lists each items potential yearly savings in a monetary and a percentage amount. Since the home has an average family in it rather than your family, the savings amounts may not relate exactly to yours, but using the percentages your savings can be calculated.

This energy audit or assessment is not only a requirement for the PG&E EUC or long term loan program but it’s also an extremely useful tool in forming a battle plan on how to attack the energy inefficiencies of your home and cut utility usage.

If You're Considering a Home Upgrade, Consider an Energy Audit First

Personally, I don’t see how a person can make serious plans about upgrading the energy efficiency of a home without having actual test results to form your plan from. If you plan to buy a new furnace for example. How do you know if you need a new furnace or if it’s something else? How do you determine whether you are buying a brand new high efficiency furnace and attaching it to ducts that leak 50% of the conditioned air into the attic or under the floor? If you buy a new furnace and then next year get dual pane windows and full insulation, how do you then know if that new furnace is then too big for this now fully insulated home? How does a person know whether to put their money in a new furnace of new dual pane windows? These are all questions answered by an energy assessment and nothing can be successfully done without one, IMHO.