When you acquire a commercial or industrial building, you are required to complete a regulatory energy audit, in accordance with the European directive in force. The overall purpose of this diagnosis is to evaluate the energy performance of the buildings. The building energy audit follows a precise approach, documented in a set of specifications.
The energy audit begins with a detailed inventory of the building. These are followed by an energy assessment and a set of advice aimed to improve the energy efficiency of the site. Finally, the role of the energy audit is to quantify the cost of potential renovations or equipment to be planned.
The key steps in performing an energy audit are defined by the ADEME (French Environment and Energy Management Agency). They are the subject of specifications intended to assist professionals in their decision-making.
1. Review of the building
Before reviewing the building, the expert collects all the data necessary for the energy audit. The goal is to get an overview of the building’s energy consumption. It is also an opportunity to develop the first ideas for improvement.
On site, the operator performs various measurements that enable him to define a “zero point”, corresponding to the existing elements that still need to be improved. The building energy audit focuses on the performance of the buildings at a specific point in time. Knowing this starting point allows the actions taken to improve the energy efficiency of the building to be as profitable as possible.

2. Data summary
With the help of a thermal camera, the expert can measure the energy losses of the house. He also uses existing documents (invoice, technical data sheet, dpe…) to draw up an initial report. The thermal study constitutes a basis for developing an improvement plan.
Following the audit, the expert has in his possession a set of information from the owner or acquirer of the building and the various studies performed. He verifies the operating conditions of this data, making sure that they correspond to the desired improvements and the problems highlighted in the building energy audit.
3. The building renovation plan or energy improvement program
Depending on the results obtained at the end of the audit, the expert determines a renovation plan or action plan. This consists of the construction of several scenarios aimed at reducing the energy consumption of the buildings.
The improvement of building performance, whatever it is, takes into account both your expectations and needs, the measures performed during the audit as well as the conclusions reached at the end of the audit.
The energy improvement program also has a financial analysis role. It makes it possible to estimate the cost of the renovations and other improvements but also to measure the return on investment of each of the scenarios for improving the energy management of the site. It allows you to know on which workstations you will perform energy savings in the long term. It can also include the public aid you are entitled to receive.
4. Presentation of the audit report
Finally, your service provider will give you a complete report including all the information relating to the building obtained during the audit phase and their details, a complete heat balance, the different improvement scenarios envisaged and a summary of the possible solutions in order of relevance.
The audit report is an essential document for both the decision-maker and the service provider. It must meet the reading needs of both parties. If the energy audit is to lead you to make a decision regarding the performance of renovation, the purchase of new equipment or any investment, it must be easy to read.
The audit report therefore provides the link between the measurements and studies performed on site, the summary of the information and the recommendations made.