Home energy rating

The energy rating is a system that classifies the efficiency of a home depending on its energy consumption and CO₂ emissions. Through a classification represented by a scale of letters -which ranges from A (for the most efficient homes) to G (those that fail in terms of efficiency)- the annual energy consumption that the construction needs to maintain optimal conditions of comfort is evaluated. In other words, the higher the home energy rating, the lower its consumption to offer the same level of comfort will be.

The system has a practical application beyond homes. Entire buildings, offices, and premises of all types, to household appliances can be subject to this evaluation with the aim of determining how efficient they are although with different procedures. In the case of homes, for example, the energy rating -mandatory for any sale or rental transaction as established by Royal Decree 390/2021-, is determined through the so-called energy certificate, a document that assesses matters ranging from thermal insulation to heating/cooling systems, to building orientation, lighting, or efficiency of household appliances. 

The energy label is a document that accompanies the rating and which provides visual information on the level of efficiency of a building or household appliance. Its main aim is to allow users to compare different options and make more informed decisions. In the case of buildings, the label not only indicates the energy rating of a home, but also shows the estimated energy consumption and CO₂ emissions. This is especially relevant because a home with a good rating can represent a significant saving in electricity bills and a lower carbon footprint.

However, it's interesting to clarify that although the energy rating of a home and the energy label of a household appliance follow similar principles, they have some differences. The aim of the rating, for example, is different. While in a home it reflects the total energy consumption necessary to keep it comfortable, in the case of household appliances, the energy rating indicates its individual efficiency compared to other similar models. Moreover, although in both cases a scale from A to G is used, they aren't equivalent. In the case of homes, the rating measures the overall building efficiency depending on its energy consumption for heating/cooling, hot water, and other structural factors while, if we speak about household appliances, its energy consumption is measured in relation to its capacity and performance (for example, how much energy a fridge uses to maintain its internal temperature).

According to Directive 2012/27/UE, relating to energy efficiency, buildings represent 40% of final energy consumption in the European Union and are responsible for a high percentage of greenhouse gas emissions to the atmosphere. Commtiting to energy efficient homes is essential to have homes that reduce their ecological footprint and, in this regard, the best rating possible is the energy rating A. This valuation indicates a minimum energy consumption and a high efficiency. In other words, these types of homes usually have good thermal insulation, heating/cooling systems that optimize resources as much as possible and, in many cases, renewable energies such as solar panels or aerothermal energy.

However, achieving this category isn't always easy. Although it is true that the energy rating of modern homes is usually higher, in old buildings the need for improvements to offset deficient insulations or obsolete energy systems is frequent. Double-paned windows, more modern heating systems, and a better electricity consumption management can be enough to improve the energy rating letter in the home.

As well as homes, household appliances also have their own energy rating scale. Up until a few years ago, the scale went from A+++ (most efficient) to D (least efficient), but today it has been simplified to go from A to G, removing the extra signs.

For example, a fridge with an A energy rating can consume up to 55% less energy than one with G which, on the contrary, could require up to 45% more energy than the average household appliance in the EU. The matter is especially important, not only because it can translate into significant savings in the long term, but because household appliances represent a significant part of the home's electricity consumption.

Although they are often used as synonyms, energy rating and energy label aren't exactly the same.

• Energy rating refers to the result of the evaluation on the energy efficiency of a home, an analysis that is supported by the corresponding energy efficiency certificate issued by a specialized technician.
• The energy label, for its part, is the document that visually shows the information and can help to choose a more or less efficient appliance. However, beyond the appliance's rating itself, this document includes other data of interest such as annual consumption in kilowatts/hour (kWh), storage capacity (according to the household appliance), noise levels... In short, it is the tool that allows consumers to interpret the information in a quick and simple manner.

Having clear energy label concepts or how home energy rating works not only helps to make better decisions in home purchase, rental, and improvement. It is also key to reducing the environmental impact of homes. We also want to contribute to this matter at Repsol with proposals such as Vivit, our app for customers which, among other things, allows you to access at all times your electricity and household appliance consumption for a more efficient management of the day-to-day in your home

At our multi-energy company, we have designed solutions adapted to the needs of homes and businesses but, moreover, we explore alternative energies and innovative products to minimize our ecological footprint.