When we talk about buying, selling, or simply saving on our electricity bill, we often come across a color-coded label that tells us how energy-efficient a house is. In reality, the Energy Efficiency it is not more than optimize the use of resources to achieve the same or even better results while using less energy. This is a key concept today, as the construction sector is one of the biggest contributors to Europe's ecological footprint.
To ensure everyone is on the same page, a standardized system has been created that allows any building to be compared, regardless of who lives there or how they use their heating. An old house that loses heat through every crack is not the same as a modern building with... near-zero energy consumption standardsIn this sense, understanding the energy scale helps us to know how much money we are throwing away and what reforms are most urgent to improve our quality of life.
What exactly is an energy efficiency certificate?
Many people confuse this document with Energy Saving Certificates (CAEs), but they are very different things. While CAEs are voluntary and serve to monetize the savings achieved, the energy efficiency certificate is a official and mandatory documentSince June 2013, thanks to Royal Decree 235/2013 and its subsequent updates such as RD 390/2021, it is an essential requirement to present it when renting or selling a property.
This document gives us a quantitative measure of how much the property consumes. To obtain it, a competent technician (This professional, who may be an architect, engineer, or other certified professional,) must analyze the building's thermal envelope—that is, the walls, roof, floors, and windows—and ensure that the hot water and heating systems are functioning correctly. The final result is a label summarizing the building's performance and a series of recommendations for improving its rating.
The evaluation process is quite meticulous. The technician doesn't just look at what's already installed, but also uses standardized methodologies to simulate the building's behavior over a full year. This avoids the result depending on whether the owner is very economical or leaves the heating on full blast, focusing purely on the technical capacity of the structure.
Detailed analysis of the scale: from A to G
The classification is presented as a letter scale accompanied by colors, where bright green represents maximum efficiency and red the most exorbitant consumption. In Spain, most homes fall into categories E, F, or G due to the age of the housing stock, but the goal is to move up the scale.
- A class: It's the jewel in the crown. These are nearly zero-energy buildings that typically integrate renewable energy and top-notch insulationThey can save up to 90% on energy compared to a G-class home.
- Class B: Very high efficiency, with modern systems and very effective thermal insulation.
- Class C: A remarkable level, above average. This is the usual rating for more recent constructions.
- Class D: It represents average performance. It is common in houses built after 2000 that meet basic requirements.
- Class E: It's the most frequently repeated category in Spain, especially in apartment blocks from the 80s and 90s. Here's a considerable room for improvement.
- Class F: Low efficiency. Typical of older homes with drafty windows and outdated heating systems.
- Class G: The lowest rating. It implies extremely high energy consumption and a very negative environmental impact.
It is important to mention that, in some systems (such as the Italian one), class A is subdivided into A1, A2, A3 and A4 to be more precise with the near-zero energy impact buildingsIn any case, the higher the letter, the greater the value of the property in the real estate market.
Key indicators and how the grade is calculated
To arrive at a letter grade, the technician relies on annual indicators related to the usable floor area of ​​the property. The goal is to determine how much energy is needed to maintain the house in comfortable conditions. The two fundamental pillars are the annual CO2 emissions (kg/m²) and the consumption of non-renewable primary energy (kWh/m²).
In addition to these overall figures, there are complementary indicators that analyze separately the expenditure on lighting, ventilation, cooling, and hot water. For new homes, the calculation is more complex and includes the building orientation and sun protection, always seeking to ensure that the house takes advantage of the sun naturally to reduce dependence on electricity.
How to improve your home's energy rating
If your house has a low rating, don't panic; there are many ways to improve it. The key is usually in the thermal envelopeReplacing old windows with double-glazed ones or adding insulation to facades and roofs can reduce energy costs by up to 50%.
In terms of technology, replacing oil boilers with systems of aerothermal, geothermal o biomass This represents a huge leap forward. The use of smart LED lighting and the installation of [other lighting systems] are also recommended. photovoltaic solar panelsThese improvements not only help the planet, but also make the house much more comfortable, eliminating problems such as... condensation and mold in the walls.
For those who don't want to spend a fortune all at once, there are the EU Next Generation AidThese subsidies cover a large part of these sustainable renovations. They can cover considerable amounts per home, facilitating the transition to carbon-neutral housing.
Differences between building and appliance labels
Sometimes we get confused because we see the same A to G rating on the refrigerator and on the building's energy certificate. However, they don't measure the same thing. While the energy rating for a house is based on the A to G rating, the energy rating for the refrigerator is based on the energy performance of the building. overall performance of the structure And its installations; in an appliance, the efficiency of a specific appliance is measured in relation to its capacity. A class A refrigerator uses less energy to maintain the same temperature as a class G one.
Since 2021, the appliance energy rating scale has been simplified to eliminate the confusing A+++ rating, returning to the A to G range. Now, class A is reserved for cutting-edge technological innovationsThis leaves room for brands to continue improving their products in the future. To verify this data, the European EPREL registry allows you to consult the actual information via a QR code.
