Implementing measures to reduce emissions in buildings throughout their entire life cycle is a special step towards transforming cities and making them more efficient and sustainable.

According to data from the European Commission, buildings are responsible for 40% of energy consumption and 36% of greenhouse gas emissions in the European Union. A carbon footprint with a very significant volume that is generated throughout all its stages – construction, use and demolition – and that comes from various energy sources.

In particular, the great environmental impact of the materials used in building works stands out, since, for example, generating a ton of cement emits a ton of CO2 into the atmosphere. But in addition, homes generate a large amount of direct emissions from their heating systems – gas or diesel boilers –, as well as indirect emissions related to the production of electricity necessary for the consumption of their inhabitants.

In order to address all these energy challenges, urban rehabilitation has gradually gained relevance in decarbonisation strategies at European and national level, with the aim of contributing to the construction of more efficient and liveable cities in the context of climate change.

New European regulations to decarbonise the sector

The European Union is working on a proposal on the energy efficiency of buildings, with the aim of reducing greenhouse gas emissions and energy consumption in the construction sector to a minimum by 2030 and achieving climate neutrality from 2050.

Among the main measures to be adopted by all member states are:

• Reducing average primary energy consumption by at least 16% by 2030 and by 20-22% by 2035 in residential buildings.
• All new buildings must be climate-neutral from 2030.
• Phasing out fossil fuel boilers and eliminating them completely by 2040.
• In the case of non-residential buildings, the renovation of 16% of the least efficient buildings by 2030 and 26% by 2033.

All of this without leaving behind the most vulnerable households and keeping in mind the fight against energy poverty when it comes to encouraging and supporting these renovations in clients with fewer resources throughout the community.

How urban rehabilitation is progressing in Spain

In the specific case of our country, we find that one of the main problems is the age of a large part of the national housing stock, since many of these buildings were built before the first regulations that established minimum criteria for energy efficiency or thermal insulation came into force.

According to the data, 55% of the building stock in Spain is from before 1980 and around 21% is more than 50 years old. Featured quote

To reverse this situation and move forward steadily on the path towards urban decarbonisation, the Government has implemented different measures aimed at reducing emissions. Among them, it is worth highlighting the Recovery, Transformation and Resilience Plan (PRTR), financed with the support of the Next Generation EU funds, and which allocates a significant part of its financial allocation to rehabilitation actions in residential buildings and single-family homes. Among the main proposals included in this plan and which are channelled through the Autonomous Communities, the following stand out:

These goals must be achieved by implementing initiatives such as improving the insulation and carpentry of buildings, installing solar panels, improving green areas and building parks, changing windows, improving accessibility, etc. In addition, to access the aid of up to 21,400 euros per home established by the plan, it is essential to prove the reduction in consumption by means of an energy certificate for the home or building, before and after the action.

Among the national measures related to improving energy efficiency in the residential field, there is also the State Housing Plan 2022-2025. This program is responsible for financing actions aimed at reducing energy demand in air conditioning, promoting the consumption of renewable energy and replacing elements such as the thermal envelope or windows.

Finally, there would also be the PREE 5000 for the energy rehabilitation of buildings in municipalities with up to 5,000 inhabitants, focused on actions such as changing the thermal envelope or replacing renewable thermal installations.

Technology and innovation

The construction sector needs solutions that allow it to adapt to the new energy needs of cities and consumers. In particular, a very relevant factor is the choice of materials and their level of sustainability, keeping in mind the revaluation of waste through the circular economy to continue advancing on its path towards decarbonisation. To find out how this challenge is being faced, you can take a look at the event “Decarbonisation of the Construction Sector (I): Technology and Innovation in Construction Materials” prepared by Holcim and Fundación Repsol.

In addition to the choice of materials, another very important field for reducing emissions from buildings is the use of innovative and renewable energy sources. This is the case of proposals such as geothermal energy, based on the use of heat energy that emanates naturally from the core of the planet and that can be used to generate electricity or directly for heating and cooling the home. The popularity of aerothermal energy has also only grown in recent years, as it is an air conditioning system that extracts the energy contained in the ambient air using a system of electric heat pumps and which has many advantages in terms of efficiency and amortization.

Not to mention other systems as practical as low-emissivity windows that improve thermal insulation, intelligent energy control and management systems such as EMS or advanced thermal insulation, to mention just a few examples of the many technological proposals available on the market to continue improving in the field of energy efficiency in the home.