Energy efficiency is one of the most important means to mitigate climate change, as the energy consuming building sector is responsible for 39% of global carbon emissions and large shares of global material use, including 50% of concrete and brick and40% of steel. With this in mind one can argue that The greenest building … has already been built (Elefante n.d.) cited by Belardi P. et.al. (2022) but the existing building stock in Europe is old and is changing very slowly. More than 220 million building units, represents 85% of the EU´s building stock, built before 2001.
Most of these existing buildings will still stand in 2050, and they are not energy efficient. Many rely on fossil fuels i.e. coal, oil and uranium for heating and cooling, and use old technologies and wasteful appliances (European Commission, COM (2020) 662 final). New buildings are more energy efficient than the older ones, but new buildings only contributes to the building stock with 2 - 4% each year. Current European situations have also resulted in a worrying stagnation in the building industry.
Nevertheless, with an expected 60% growth of the urban built environment by 2050 and significant demand for housing upgrades in urban areas, decarbonisation of the building stock is critical to meet climate change mitigation goals set in the ParisAgreement (Nußholz et al., 2023).
The need to refurbish existing buildings is usually considered to be just a reduction in operational carbon emissions related to the use and maintenance of buildings. However, these actions neglect embodied emissions associated with constructing structures, representing between 31% and 44% of the total emissions for buildings with a 60-year expectancy. With the aim of the EU to lower greenhouse gas emissions (GHG) by 80-95% by 2050, compared to the 1990s levels, a significant reduction in embodied emissions in the EU building sector will be required (Gallego-Schmid et al., 2020).
One possible way to obtain these goals is transition from a linear economy to a circular economy(CE), which could support minimising resource depletion, environmental impacts ,and waste within the built environment (Stijn 2023).
According to Gallego-Schmid et al. (2020) and Stijn (2023),the current way of producing goods and services, which involves extracting natural resources, using them to make products, and then disposing of them after use, cannot continue indefinitely. Instead, we need to shift towards reusing biological and technological resources for as long as possible. This shift is necessary due to the growing demand for resources and the environmental damage caused by their extraction and processing.
Addressing the gap in understanding operational and embodied emissions requires concerted efforts from policymakers, industry stakeholders, and society. Therefore, accelerating building renovation efforts and prioritising energy efficiency can achieve significant environmental, social, and economic benefits while prolonging the lifecycles of the existing building stock.
One game-changing document is the European Green Deal from 2019. In response to these challenges, it aims to promote a new growth strategy based on a resource-efficient and competitive economy with no net emissions from green house gases by 2050 (European Commission, COM/2019/640final).
The Energy Efficiency First principle complements this and other EU objectives in the field of sustainability and climate neutrality. The aim is to ensure that only really needed energy is produced and emphasises the need for reducing fossil fuel consumption. Energy Efficiency First supports a sustainable approach to the use of limited resources and increases the resilience of the EU’s energy system.
In September 2023 the Energy Efficiency Directive (EU/2018/2002) was revised in EU/2023/1791, providing a stronger and wider legal basis for the application of the principle. It demandsEU countries to ensure that energy efficiency solutions are considered in planning, policy, and investment decisions in both energy and non-energy sectors.
The Commission also made a recommendation EU2021/1749 supporting the Energy Efficiency Principle by identifying specific actions to be taken by the EU countries to ensure a proper application with detailed guidelines in the annex.
So, how do we reach sustainability in the built environment through energy efficiency? The simple answer is that we need to decarbonise the building sector, but what measures do we need to implement? Well, we need to use materials with no or low carbon footprint e.g.reused/recycled material and see to that the building envelope is well insulated. We live most of our lives indoors which requires a good indoor climate, whether the need is heating or cooling or proper ventilation, and we do not want to have air draught.
Our energy market has shown to be shaky and vulnerable so our energy systems for heating and hot water must be adjustable to any energy source. In practice it means based on heated water in the street as well as in the building e. g. district heating, DH, based on renewables and low temperature excess heat gained from industry and other heat generating installations, activities, and companies a.k.a. 4th generation district heating, 4GDH. Energy efficient electric appliances and lighting on top of all this will bring us nearly zero energy buildings with an extremely low carbon footprint for use in a sustainable future.
Belardi, P.; Gusella, V.; Liberotti, R.;Sorignani, C. Built Environment’s Sustainability: The Design of the Gypso |TechA of the University of Perugia. Sustainability 2022, 14, 6857.https://doi.org/ 10.3390/su14116857
COM/2019/640final. The European Green Deal. Bruxelles:The European Commission.
COM(2020) 662 final. A RenovationWave for Europe - greening our buildings, creating jobs, improving lives.Bruxelles: The European Commission.
COMMISSION RECOMMENDATION (EU) 2021/1749 of 28 September 2021 on Energy EfficiencyFirst: from principles to practice — Guidelines and examples for its implementation in decision-making in the energy sector and beyond. Bruxelles:The European Commission. © EUR-Lex, 04/10/2021, eur-lex.europa.eu
DIRECTIVE (EU) 2023/1791 OF THE EUROPEAN PARLIAMENT AND OF THE COUNCIL of 13 September 2023 on energy efficiency and amending Regulation (EU) 2023/955 (recast).
Gallego-Schmid,A., Chen, H. M., Sharmina, M., & Mendoza, J. M. F. Links between circular economy and climate change mitigation in the built environment. Journal ofCleaner Production Volume 260, 1July 2020, 121115. Elsevier Ltd. https://doi.org/10.1016/j.jclepro.2020.121115
Kunic N. (2024)Transforming a building through the implementation ofCircular Economy Principles. Master Thesis. Halmstad University.
Norrström,H. Sustainable and Balanced Energy Efficiency and Preservation in Our BuiltHeritage. Sustainability2013, 5,2623-2643. doi:10.3390/su5062623
Norrström H. (2021) Ranagårdwith new 4GDH Technology. ID 8-149-21 in A new reality-eceee. Summer Conference pp. 1047-1054.
Nußholz, J., Çetin, S., Eberhardt, L., De Wolf, C., & Bocken, N. From circular strategies to actions:65 European circular building cases and their decarbonisation potential. Resources,Conservation and Recycling Advances Volume 17, May 2023, 200130. Elsevier Inc. https://doi.org/10.1016/j.rcradv.2023.200130
van Stijn A. (2023) Developing circular building components – between ideal and feasible. Doctoral dissertation. Delft University of Technology.
Guest blog post by Heidi Norrström, Architect, Assistant Professor| Ph.D. in Energy efficientBuilding, Department of Construction and Energy Engineering, School ofBusiness, Innovation and Sustainability, Halmstad University, Sweden, & Nada Kunic, Architect, Department of Construction and EnergyEngineering, School of Business, Innovation and Sustainability, Halmstad University, Sweden.
