City of Alexandria, VA
Page updated Jul 27, 2012 9:25 AM
Energy Audits: A smart way to determine the best green improvement for your buck
An energy audit is often the first step to making a home or building more efficient. During an energy audit (also called an energy assessment), a trained professional will evaluate the existing structure to determine how energy is being used in a building. They will then determine what problems may, when corrected, significantly lower utility costs. The audit alone won’t save you energy but the analysis will give you a framework of which energy improvements will give you the best bang for your buck.
Energy audit companies generally will offer two types of audits. A building energy survey is a visual walk-through inspection that does not use diagnostic testing equipment. The auditor will assess the general energy performance of the building, such as the age of the building envelope and HVAC system. They will also perform a utility analysis and check for visible health and safety concerns. This kind of audit is cheaper than a more in-depth performance energy assessment known as a comprehensive building audit. A comprehensive building audit includes diagnostic testing that requires specialized equipment. These tests determine the amount and location of air leaks in the building envelope and from the HVAC system. They also determine the effectiveness of the building’s insulation. Both energy assessments require 12-36 months of utility use history. These records can easily be obtained from your utility provider. Certain tests will also require scaled floor plans so be sure to ask what documents you will need before your audit.
Energy audits typically cost a few hundred dollars for a home and as much as a few thousand dollars for larger commercial buildings. While this may sound costly, utility savings after repairs pay for the price of the audit quickly and the environmental benefits of saving energy are immediate. When selecting a company to work with, be sure their auditors are certified as either a building analyst by the Building Performance Institute (BPI) or as a RESNET (Residential Energy Services Network) certified HERS rater. A list of energy auditors in the Alexandria area can be found here.
Once you have chosen a company, the auditor should inform you of a scope of services as well as all applicable charges before conducting the energy audit. Be cautious of companies that offer free audits as their goal may be to sell expensive repairs and products. Some companies only do energy audits and may be more likely to provide you with an accurate report.
The City of Alexandria has conducted eight sample energy audits on a variety of buildings, ranging from single-family residential homes to commercial buildings. They have posted the case study results online at their Green Building Resource Center. These audits can help you determine what procedures may take place during your audit and can provide a more tangible example of what suggestions you may be given for your building. It is important to remember that each building begins at a different point in energy efficiency. Two commercial buildings built in the 1980s might receive very different suggestions for ways to improve their energy efficiency. For example, while many large buildings can save money by replacing their boiler, Grace Episcopal Church in Alexandria found their boiler to be very efficient but found that their lighting system could be improved to save on energy costs. Alternatively, a nearby church with highly efficient lighting may be losing a large percentage of its energy due to poor roof insulation. While a do-it-yourself walk-through is a good place to start to address “low hanging fruit,” a professional energy auditor can provide you with whole-building suggestions on where to focus your energy efficiency improvements, maximizing your energy savings.