Initially, energy audits became popular in response to the energy crisis of 1973 and later. However, as our understanding of the human impact on global warming and climate change grows, interest in such audits increases respectively, as it helps us to improve our habitat to be as energy efficient as possible.

Energy efficiency seems an obvious goal. But when we look at the many ways that energy is part of our lives, and consider the cost versus benefit of getting more productivity out of every euro spent on energy, we realize how complicated the pursuit of efficiency becomes.

So, what is an energy audit?

An energy audit is an inspection, study and analysis of the energy fluxes of a home or building (residential or non-residential), with the objective of bringing to light a series of energy saving and efficiency opportunities. It allows an action plan to be drawn up based on the previous study, where improvement measures are proposed so that energy consumption is lower and more efficient. Improving and saving energy consumption not only has a positive impact on the environment, but also on economic savings.

Generally, an energy audit can be done anywhere where there is high energy consumption, and you want to reduce that consumption in order to save both energy and money.

How to perform an energy audit?

When the benefits of an energy audit are evident, it is normal that questions arise as to who can perform one and how. Since the inspection has to be carried out by a certified technician, it is normal to hire a company (such as “Arcostec”) that can carry out the audit. From the owner’s point of view everything is very simple: he only has to provide the required information and provide the technician with access to the facilities.

From there, the rest of the inspection falls on the auditor, who will follow certain steps and stages, which are the following:

1. Planning and data acquisition.

  • Interview and information gathering. Initial meeting with homeowners to gather relevant information and plan next steps.
  • Visual inspection. The auditor tours the facility and performs a visual inspection to get an idea of the condition of the facility.
  • Questionnaire to users of the building. Questions are asked about the degree of comfort with which the owners live and the particular consumer habits.
  • Preliminary report. The auditor issues a report detailing initial findings and future steps.

2. Experimental Measurements

Experimental measurements are made on the basis of the results obtained previously and the data measured is compared with the data provided.

3. Diagnosis of the situation.

The necessary calculation begins with the values obtained previously to obtain the final values and, in this way, check whether the parameters comply with the regulations or not.

4. Analysis and proposal for the improvement of housing performance.

The deviation that may exist between the data obtained and the optimal data that should exist is calculated. With these data, a list of proposals is drawn up to improve the energy efficiency of the building, reflecting the savings that its application would imply, in terms of energy (kWh/year), economic (euros/year) and environmental (kgCO2/year).

5. Issuing the final report

Finally, all the data is collected in a report that is given to the client.

What is measured in an Energy Audit?

Once we know the steps that the auditor follows to perform the inspection, another question that may arise is what are the parameters and installations to be measured. These are the elements that are measured to carry out a correct energy audit.

Energy consumption

By analyzing the energy bills and the data obtained from the meters, a comparison is made between the actual data and the optimal data.

Analysis of the power grid

The amount of reactive energy that is not consumed is analysed.

Thermal enclosure

Enclosures, thermal bridges, openings and all possible scenarios where energy losses may occur.


An inventory is made of all the existing illumination elements in order to know the energy consumed.

Air conditioning and DHW

The existing generation elements and distribution systems are analysed in order to optimise the system.

Control and management

The devices used to monitor consumption are checked for correct operation.


Inventory of all electrical equipment (air conditioning, ventilation, boilers, pumps, etc…) to know the current consumption


Please contact the Arcostec team of specialists for any information you may require. We will answer you as soon as possible. Our commitment is to provide professional and personalised advice to our clients


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