The State of Energy Efficiency in Spain 2026

The Real Estate sector: a key driver of energy transition

• The real estate sector is one of the main emitters of greenhouse gases and one of the largest consumers of materials and energy on a global scale. In 2025, it was responsible for around 37% of global carbon dioxide emissions and 50% of global material extraction, with residential buildings accounting for around 70% of the sector's energy demand.

Growing energy certification activity

• 39.1% of the Spanish residential stock has an associated energy certificate. The provinces with the highest coverage are Madrid (69.0%), Navarra (58.0%), Barcelona (55.3%), and Málaga (51.8%).
• Energy certification activity is heavily concentrated in urban centres. 51.6% of multi-family homes have an associated energy certificate, compared to just 17.5% of single-family homes.

Significant impact of regulation and public aid

• Since 2013, the issuance of energy certificates has followed an upward trend, with two marked boosts in 2016 and 2021. These milestones are linked to the structural deployment of the National Energy Efficiency Fund and the Next Generation Funds, respectively, set within an increasingly strict and ambitious regulatory context.
• In 2025, a historical record was reached, with more than 1.3 million certificates issued. The notable increase in energy retrofits since 2015 confirms the critical importance of public aid in driving energy efficiency improvements across the housing stock.

A currently inefficient residential stock

• We estimate that 94.2% of the residential stock is energy inefficient, showing a high concentration in the “E” rating. This situation is a direct consequence of the age of the building stock, which was constructed under older regulatory standards exempt from energy efficiency requirements. New construction housing, which is subject to strict modern efficiency standards, represents barely 4% of the total.

Renovation, the key to decarbonization

• Homes are long-term assets, with an estimated useful life of between 50 and 100 years. Given the marginal weight of new construction, renovating the existing stock is the most effective pathway to achieving climate objectives.
• Energy renovations demonstrate a significant impact on energy consumption: they achieve consumption reductions of between 25% and 75% in most single-family homes, and improvements of between 10% and 50% in multi-family homes.

The challenge of the 2030 targets

• Spain faces a challenge of considerable scale. Among its decarbonization targets is a mandatory 26,394 GWh reduction in final energy consumption within the residential sector by 2030. This target implies retrofitting the thermal envelope of 1.2 million homes and replacing more than 3.5 million heating and domestic hot water systems before 2030.
• If the volume of energy renovations undertaken during the 2020–2025 period is merely maintained, the residential stock will remain mostly inefficient in terms of consumption by 2030. We estimate that it would be necessary to multiply this volume by five over the next 5 years to approach an intermediate efficiency scenario, and by ten to reach a mostly efficient scenario.