Things to Know Before Conducting a Building Energy Audit

With winter in full swing across the northern hemisphere, the cold air (or perhaps a quick review of the last heating bill) has prompted residents and building managers to take note of where cold air might be leaking into a building. 

Heat loss can account for up to 50% of total energy consumption in a building. Reducing and eliminating air leaks is typically the most cost-effective method for reducing energy costs while improving building durability and occupant comfort.  

But how does one go about finding those leaks, let alone addressing them? That process begins with an energy audit—a building assessment designed to detect and record the current  energy consumption of the building and to identify areas where the building can become more energy efficient. An audit can reveal minor inefficiencies—easily remedied with simple fixes such as adding weather stripping around windows—or help locate potentially larger issues before they become expensive to remedy.

Recorded Webinar - Thermal Home/Building Inspection
Learn more about thermography for building inspections

Watch now

Conducting an effective energy audit requires (a) knowing the building in question, (b) acquiring the right tools for the joband (c) an understanding of building design and its overall environment. 

Know the Building 

An important factor to consider before jumping into an energy audit is gaining an understanding of the building in question.  

Consider the historyKey questions to ask and determine are: the general age of the structure, its history of rehabilitation, and any other events that changed or affected the function of the building. That information can provide crucial context during the course of the audit, especially as part of the due diligence required in purchasing real estate. 

Examine the materials. What materials were used to construct the building and/or rehab the structure inside and out? Are there known areas where such materials typically begin to degrade and invite outside air to enter?  

Tools of the Trade 

Often, major energy efficiencies in a building are invisible to human senses. This requires the use of specialized tools to detect the source of air leakages and energy inefficiency. Chief among these tools is thermal imaging. The ability to detect and visualize infrared (heat) energy is the single most effective method to locate potential energy problem areas. 

For homeowners, FLIR ONE Edge ProFLIR ONE Pro, and FLIR ONE Pro LT thermal camera attachments offer a cost-effective solution for conducting seasonal home energy audits. For professionals, the standalone C3-XC5, Ex-Series, or Exx-Series thermal imaging devices provide a level up with increased battery power, along with more features and a ruggedized form factor to handle repeated use, day in and day out 


Is this a moisture problem or missing insulation?

However, the ability to detect “cool” spots with a thermal camera within a home does not necessarily mean that cool spot is an air leak. It could also be moisture that has entered the building from the outside, or from a leaking pipe or shower drain.

In these situations, FLIR recommends the use of a moisture meter to confirm water intrusion. Undetected water leaks within a building can result in catastrophic damage along with increased danger to occupant health by promoting mold growth. The FLIR MR160 offers both pin and pin-free moisture detection along with a built-in thermal camera to help quickly identify areas for further testing and remediation. 

Another important tool? Reporting software. Professionals who perform detailed inspections need reporting software that not only provides editing and analysis tools, but also allows them to output reports. FLIR offers two levels of software that can perform the job well: FLIR IgniteTM and FLIR Thermal Studio Suite. Cameras with FLIR Ignite automatically upload images to secure cloud storage where users can organize and share images as well as output simple reports. For advanced analysis and decision-making, FLIR Thermal Studio software (Starter, Standard, and Professional) offers a rich set of measurement tools, batch processing, the ability to pre-plan inspection routes, and customized report templates.

Understanding Building Design 

Historical knowledge of the building in question along with the right tools can help anyone quickly locate potential issues. However, to conduct a truly comprehensive energy audit, the inspector must possess a basic understanding of building design and external factors that can affect building’s performance 


Thermographers often inspect homes and buildings in the early morning to avoid the effects of solar loading. 

Every building is constructed with controlled air flow in mind to increase the comfort of its occupants and for general occupant safety. Understanding the basic engineering of the building design can help guide the auditer to determine where uncontrolled air leakage is occurring.  

Furthermore, outside weather can play a significant role in conducting an accurate energy audit. Significant contrast between the outside air temperature and the indoor air temperature provides the best scenario to locate potential problem areasHowever, the weather can also work against an accurate audit, even with significant temperature contrast.  

Troublesome weather factors include solar loading and wind. Solar loading can help camouflage potential issues, especially on the sides experiencing direct sunlight. Similarly, wind can temporarily hide more issues by washing out the air pressure differences between inside and outside air, making detecting air leaks with a thermal camera significantly more difficult than in calm weather. 

For more details on conducting energy audits, including additional tools, tips, and resources, visit: 

Related Articles