Self-evaluations and Free tests
Whether doing your own audit or having someone from the utility company take a look at your home will, in my opinion, provide about the same level of results. A self-audit requires a bit of homework to identify issues you may have in your home and how to correct them. (And taking the time to understand how your home functions can be extremely valuable.)
Guidance on doing it yourself can be found through the Energy Star program Home Improvement website. This information focuses on the biggest losers of energy first, air sealing and insulation, and works its way up to bigger ticket items such as heating and cooling systems.
Audits that are conducted as part of a utility's customer service often follows a similar approach without the need of a homeowner doing research. Generally, the auditor will go through your home to identify issues that are costing you money such as where air leaks are occurring or where you don't have enough insulation. They may also be able to evaluate items such as your heating and cooling system and make specific recommendations about what should be updated or corrected to reduce your utility bills.
Note that I haven't mentioned replacing windows up to now. A common misconception is that replacing your windows will save big money, but far too often the return is limited and ineffective without fixing other things first. Your home is a system and if you don't look at the whole picture, you might as well throw your money right out of those new windows.
That leads to a discussion of benefits with...
Professional Energy Audits
Your typical professional energy auditor is certified through RESNET and is qualified to perform audits that allow a new home to be labeled as ENERGY STAR rated or provided funds for updates through an Energy Improvement Mortgage.
There are a few significant differences you should expect from a professional audit including:
- A blower door air leakage test
- Infrared (thermal) imaging of trouble zones
- Pre-audit interview and questionnaire
- Analysis of past utility bills
- Personalized report of energy findings
- Financial analysis report that prioritizes upgrades for comfort and return on investment
- HERS rating
Where I see these audits really paying for themselves is in the interview / financial analysis aspects. When evaluating an existing home, these auditors take the time to discuss exactly what you hope to achieve and make specific recommendations that fulfill stated goals. For example, if you expect to live in your home for only 5 years, then they can identify specific improvements that will save you money for that period of time. Similarly, if you plan to make upgrades with funds from a mortgage, then the auditor will produce a report of cost-effective improvements that will lower your total monthly costs over the term of the loan (and improve the value of your home at the same time).
Thanks to Chris Dwyer @ Emotiv for input to this article