Energy efficiency has become a key criterion for investors, developers, and users. Discover how and why sustainable real estate assets have become a decisive factor for a project’s success
In recent years, Europe has experienced strong volatility in energy prices, highlighting the vulnerability of the traditional energy model. This situation has directly impacted household economies and the competitiveness of many sectors, emphasizing the need to accelerate the transition to cleaner, safer, and more efficient sources. In this context, energy efficiency and self-sufficiency are becoming increasingly important, especially when extreme temperatures—whether in winter or summer—significantly boost energy demand.
According to data from the European Union (EU), buildings—key to achieving energy and environmental goals—account for 40% of primary energy consumption and 35% of CO₂ emissions.
With a construction sector that is expanding—where it is estimated that a quarter of the building stock of 2050 has yet to be built—the EU considers it a priority to reduce energy consumption in both new and existing buildings. This need is framed within the European Green Deal and the climate and energy targets for 2030, which aim to reduce greenhouse gas emissions by at least 55% compared to 1990 levels. Currently, 75% of existing buildings are energy inefficient and require extensive renovation to move toward climate-neutral cities that are less dependent on external sources and more resilient.
Advantages of Having Sustainability Certifications
Having certifications such as BREEAM, LEED, or Passivhaus is a strategic investment that generates both economic and reputational value for developers, investors, and users. These internationally recognized accreditations validate a company’s commitment to sustainability and efficiency, translating into concrete advantages:
- Improved market positioning: The property stands out among other assets and attracts investors and users whose profiles are increasingly demanding and aligned with ESG criteria.
- Reduction in energy consumption: This results in a lower environmental impact and optimizes operating costs over the medium to long term.
- Regulatory compliance and proactive regulation: This is crucial in an increasingly strict legislative context regarding energy efficiency and decarbonization.
- Competitive differentiation: Especially in a transforming market where sustainability is no longer an added value, but an essential condition.
- Asset revaluation: Increased efficiency and resilience lead to infrastructure that is better prepared to face regulatory, economic, and environmental changes.
- Enhanced comfort and well-being: Higher standards in air quality, natural lighting, thermal and acoustic insulation improve user satisfaction.
- Strengthened corporate reputation and environmental commitment: Reinforcing the image among investors, operators, and end customers.
Sustainability Certifications for Buildings: Which Are the Most Important?
There are highly prestigious certifications at the international level, both private and public, that assess energy efficiency, sustainable construction, and carbon footprint. The most well-known are:
BREEAM Energy Certification
The British BREEAM® or “Building Research Establishment Environmental Assessment Method” was developed by the Building Research Establishment (BRE) in the 1990s and also assesses aspects beyond energy efficiency, including sustainability and health.
It aims to ensure efficiency, reduce maintenance and operating costs, and increase user satisfaction and well-being. It has 5 levels:
- Sufficient
- Good
- Very Good
- Excellent
- Exceptional
LEED Energy Certification
The American LEED, “Leadership in Energy and Environmental Design,” was created in 1993 as a tool to promote eco-friendly construction. Based on a maximum score of 100, LEED technicians rate aspects such as location and transportation, water efficiency, energy and atmosphere, materials, resources, and air quality. Its objective is to improve energy savings, water efficiency, resource management and conservation, as well as to reduce waste and CO₂ emissions. It has 4 levels:
- Certified
- Silver
- Gold
- Platinum
Passivhaus Certification
The German Passivhaus originated at the Passivhaus Institute in Darmstadt (Germany) in the 1990s and has been successfully applied internationally. This voluntary energy certification is designed for new constructions and renovations and is applicable to any climate.
The basic concept of Passivhaus is the focus on the building’s energy demand throughout its lifetime, based on the following principles:
1.Excellent thermal insulation.
2.Elimination of thermal bridges.
3.High-performance carpentry.
4.Airtightness.
5.Mechanical ventilation with heat recovery.
GREEN Certification
Developed by the Green Building Council Spain (GBCe), the GREEN certification assesses a building’s sustainability based on its environmental impact throughout its entire life cycle: from design and construction, to its use, maintenance, and eventual demolition.
It allows for quantifying the energy and environmental savings of a property in key areas such as water consumption, energy efficiency, indoor environmental quality, user health and well-being, as well as the CO₂ emissions produced. Furthermore, GREEN is aligned with the Sustainable Development Goals (SDGs) and European standards for sustainable buildings.
WELL Certification
The WELL certification, developed by the International WELL Building Institute (IWBI), is the first standard focused exclusively on the health and well-being of the people who occupy or work in a building. Through a scoring system based on scientific evidence, it evaluates aspects such as air quality, access to natural light, water quality, thermal and acoustic comfort, nutrition, physical activity, emotional state, and social connectivity.
DGNB Certification
DGNB certification seeks to help organizations improve tangible aspects of sustainability. It has 4 levels:
- Bronze
- Silver
- Gold
- Platinum
Certificación HQE
The objective of HQE certificates is to ensure that the high-quality nature of a sustainable project is objectively recognized on an international level.
How to Interpret a Building’s Energy Rating?
Since 2008, every new building in Spain must have, at minimum, an energy rating of “C”. However, buildings that incorporate internationally recognized sustainability certifications—such as BREEAM®, LEED, or Passivhaus—far exceed this threshold, reaching significantly higher levels of efficiency.
A concrete example is Kora Green City, our flex living complex located in Vitoria-Gasteiz, which has been certified with the Passivhaus standard and holds an energy rating of “A”. Moreover, it is backed by the Guarantee of Origin (GdO), which certifies that its consumption comes from 100% renewable sources. Thanks to passive design and the use of high-efficiency technologies, Kora Green City has managed to reduce the building’s energy consumption by 76%, avoiding the emission of 164 tons of CO₂ per year — equivalent to approximately 1,050 trees planted each season. Similarly, Kora Pamplona will feature 80 solar panels, each with a peak power of 540 Wp, providing an annual production of 56,160 kWh, which will reduce energy demand by at least 50%.
According to a study by the Organization of Consumers and Users (OCU), most domestic consumption comes from appliances, which account for 55.2% of the total, followed by lighting (11.2%), cooking (9.2%), air conditioning (7.5%), and heating (7.4%). Among appliances, the refrigerator stands out as the most energy-demanding, representing 30.6% of the total consumption, followed by the television (12.2%), washing machine (11.8%), oven (8.3%), computers (7.4%), freezer (6.1%), and dishwasher (6.1%).
In this scenario, the energy efficiency label has consolidated over the past 25 years as a key tool to help consumers choose more efficient and sustainable products. It has also driven innovation in the design of appliances with lower energy impact. For example, a refrigerator with an “A” rating can consume up to 80% less than one labeled “D”.
In March 2021, the labeling system was updated to simplify its reading and adapt to technological advancements. The “+” signs (A+, A++, A+++) were removed, returning to a clearer scale that ranges from A (green), for the most efficient products, to G (red), for the least efficient. This new classification is based on the Energy Efficiency Index (EEI), which takes into account the appliance’s annual energy consumption and performance in each cycle or use.
How to Read and Interpret the New Energy Label?
With the entry into force of the new European regulations, not only has the design of the label been simplified, but the efficiency calculation method has also been updated. Therefore, there is no direct equivalence between the old labels (with “+” signs) and the new ones. The same appliance may now show a different energy consumption compared to previous versions, even though the model itself has not changed.
Here we explain the main elements of the current label:
- Energy Class: The new scale includes seven levels, from A (dark green, most efficient) to G (red, least efficient). The product’s energy class is displayed in a highlighted box, indicating the category to which it belongs based on its performance.
- Stricter limits: The requirements to achieve each class have been significantly tightened. Many products that previously appeared as A++ or A+++ may now fall into lower classes.
- Annual energy consumption: The weighted energy consumption is indicated, expressed in kWh for every 100 use cycles. For washing machines, for example, the calculation is based on the “Eco 40-60” program, providing a realistic estimate of the appliance’s typical usage.
- Pictograms: The label includes a series of icons that summarize the product’s most relevant features. In the case of washing machines, these include:
- Load capacity (in kg)
- Duration of the Eco 40-60 cycle (in minutes)
- Water consumption per cycle (in liters)
- Centrifugation efficiency class (from A to G)
- Centrifugation noise level (dB(A))
- Acoustic emission class (from A to D)
As a new feature, a QR code is included, allowing the consumer to scan it with a mobile device to directly access the official technical data sheet of the model in the European EPREL (European Product Database for Energy Labelling).
The Importance of Correctly Interpreting the Energy Certificate
Understanding a home’s energy certificate goes beyond just a letter on a label: it allows you to estimate how much it will cost to maintain the property in terms of energy consumption and, therefore, how much you can save—or lose—each month.
For example, a home with a low energy rating (class E, F, or G) may have high heating or cooling demands. In these cases, the energy bill can be twice as high compared to a home with an A certification. This not only implies higher economic costs but also a greater environmental impact.
In contrast, a home with an A or B rating is designed to optimize consumption, make better use of natural light, maintain a comfortable indoor temperature with fewer resources, and reduce thermal losses. In practice, this can translate into hundreds of euros of annual savings on the energy bill, in addition to increased comfort for its inhabitants.
Thus, correctly interpreting the energy certification allows you to make informed decisions, compare properties with a critical eye, and, above all, control the daily costs associated with their use.
The Future Challenge: Positive Buildings and Homes
Beyond energy-efficient appliances with a “green” rating or sustainable certifications, the real change lies in rethinking the building as a whole. Today we talk about positive homes: energy-positive buildings that are capable of producing more energy than they consume. This is part of a trend toward energy generation as a normal element of the domestic ecosystem.
Kategora Real Estate argues that it is possible to generate a positive impact on the planet without compromising profitability. This vision has already materialized in projects such as Kora Green City or Kora Nivaria Beach, where sustainable architecture, passive design, the use of low-impact materials, the incorporation of photovoltaic panels, geothermal production, and high-performance air recovery systems (aerothermal systems) allow for the development of buildings with very high energy efficiency, as well as being resilient, durable, and responsible.
The challenge is to build with a perspective that considers not just the present, but the entire life cycle of the property. For this reason, Kategora Real Estate applies circular economy principles in architectural design, prioritizing solutions that facilitate efficient management and reduce the overall environmental footprint.
Against a linear model of consuming and discarding, energy intelligence applied from all angles closes the sustainability circle toward a circular economy. And positive homes—autonomous, connected, healthy—are the immediate future, not a distant utopia.
