The concept of energy efficiency is becoming increasingly important in the real estate sector. Both the industry and society at large have realised that we need to change our traditional patterns of resource consumption in order to move towards a more sustainable and responsible model.

Managing energy resources is everyone’s responsibility and the housing sector in particular plays a crucial role, since it is one of the sectors that consume the most energy annually. According to the European Union, buildings accounts for 40% of the continent’s energy consumption, and in Spain, according to the Institute for Diversification and Energy Saving (IDAE), some 25% of energy is consumed in homes.

For this reason, the real estate model has been evolving to adopt new, more efficient construction criteria. But this is a gradual process and, in the meantime, not all homes are equally energy efficient.

This is where energy certificates come in. They tell us whether the changes are moving in the right direction.

What are energy certificates and why are they important?

Energy certificates are official documents that grade the energy efficiency of a home or building. They are awarded on the basis of a technical assessment of the property’s energy consumption and associated CO₂ emissions while in daily use. In other words, in order to obtain a certificate the property has to pass an examination.

Specifically, an energy certificate will show: the home’s energy rating, its annual energy consumption (in kilowatt-hours per square metre), volume of CO₂ emissions, and recommendations for improvement.

An energy certificate is important because it tells us whether a particular home or building meets the new environmental standards and whether any improvements are required. It can also increase a property’s value if it shows that the property meets sustainability requirements and so will save its residents energy, and thus also money.

What types of certificate are there and how are they awarded?

At present, several different energy certificates are used. Let’s take a closer look:

• Energy Efficiency Certificate (EEC): This is the best known and most widespread type, since it is mandatory for selling or renting a property. It grades a building’s energy efficiency on a scale from A (highest efficiency) to G (lowest efficiency). An EEC is valid for 10 years.
• Passivhaus certificate: A voluntary certification which shows that a property meets the requirements of the Passivhaus Standard, which means it has very low energy consumption. The standard is designed to optimise energy demand through excellent insulation, controlled ventilation and absence of thermal bridges.
• BREEAM (Building Research Establishment Environmental Assessment Method) certificate: A voluntary certification that evaluates a building’s sustainability and energy efficiency, considering factors such as materials, water and waste management, interior comfort and energy efficiency.
• LEED (Leadership in Energy & Environmental Design) certificate: Similar to BREEAM but US-based. It measures sustainability and energy efficiency in building design, construction and maintenance.
• VERDE certificate (Building Efficiency Reference Valuation): A Spanish certification created by the Green Building Council Spain. It measures environmental impact and energy efficiency in various categories, including energy use, materials and comfort.
• Existing Building Book (Libro del Edificio Existente, LEE): This is a document that compiles information on the state of conservation, energy efficiency and potential for improvement of an existing building. It is linked to government subsidies for energy rehabilitation in the context of the Next Generation EU funds.

In summary, we already have at our disposal a range of certificates that tell us whether a home meets environmental requirements, which is set to become increasingly important, both in buying and selling and in renting.