Practices

OVERVIEW | Socioeconomic and technical approaches to building stock renovation

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Renovating the EU building stock

Deep renovation of buildings has the potential to cut 36% of their energy consumption by 2030, while reducing the EU’s dependency on imported energy, creating growth, innovation and employment, reducing fuel poverty and resulting in more comfortable and healthier buildings.

 

EU legislative initiatives have been introduced to encourage building renovation, such as the Energy Performance of Buildings Directive (EPBD) and the Energy Efficiency Directive. The recast [2018/844] of the EPBD [2010/31/EU] sets a clear direction for the full decarbonisation of the European building stock by 2050 and it provides a clear goal for Member States and the approach to achieve it [1].

 

EU countries are required to adopt a long-term renovation strategy, which is now set out in Article 2a of the Energy Performance of Buildings Directive. These strategies will support the renovation of the national stock of buildings into a highly efficient and decarbonised building stock by 2050. In addition, a cost-effective transformation of existing buildings into nearly zero-energy buildings will be part of EU countries’ integrated National Energy and Climate Plans. Long-term renovation strategies must also be underpinned by a solid financial component (effective use of public funding, aggregation, de-risking).

 

EU recommendations on the modernisation of buildings

The building sector is the single largest energy consumer in the EU and it has been observed that 75% of the EU’s buildings are energy inefficient. A modernised and refurbished building stock therefore has a key role to play in the transition to a smarter, renewable-intensive and decarbonised energy system, and in the longer term to a climate neutral economy. The EPBD is the main legislative instrument for the promotion of energy performance improvements in buildings within the EU, and it has been further clarified and deepened by the guidance on building renovation that was published in May 2019. Taken together, these two key documents aim to ensure a uniform understanding across Member States in the preparation of their transposition measures, keeping in mind that this does not alter the legal effects of the directive itself.

 

The revisions to the EPBD was the first dossier in the Clean energy for all Europeans package to be adopted, entering into force on 9 July 2018. Member States have until 10 March 2020 to transpose the new and revised provisions of the directive into national law [2]. The Clean energy for all Europeans package consists of eight legislative acts (Energy Performance of Buildings, Renewable Energy, Energy Efficiency, Governance of the Energy Union, European Union Agency for the Cooperation of Energy Regulators, Risk preparedness, Electricity regulation, Electricity Directive) that will allow for improved energy efficiency in buildings in order to foster the transition towards a highly energy efficient and decarbonised building stock by 2050, reaching the target of 32% for renewable energy sources in the EU’s energy mix by 2030, reaching at least 32.5% energy efficiency by 2030.

 

Challenges to large-scale building renovation

Some of the main challenges for deep renovation of the EU building stock lie in the fact that decisions on the depth of renovation are governed by the investment costs and overall cost-effectiveness of the investment. Therefore, one of the key issues for the uptake of deep renovation is the definition of more cost-effective business models that can make the initial investment more sustainable for the stakeholders. This is to be achieved through several coordinated measures including stimulating technological innovation related to both building envelope and technical systems and tailoring standardised solutions for each construction phase, climatic zone and building type. Moreover, defining solutions for aggregating single building owners bundling properties into single, large-scale energy renovation projects is strategic to speeding up the renovation process.

 

High up-front costs of (deep) energy renovation are the primary barrier to its large-scale implementation. The success of energy efficiency policies in the residential building sector heavily depends on the households’ involvement. New business models that will stimulate the energy renovation market and engagement of private capital are necessary to boost large-scale energy renovation of buildings in the EU.  For example, the FinEERGo-Dom project guarantees financing schemes for energy efficiency and renewable energy in deep renovations of buildings across Eastern Europe. The TripleA-reno project aims at providing end-users of deep renovation projects with understandable and personalised information by fostering consumer-centred business models that will provide data about indoor environmental quality, energy use, and health and well-being indicators after a deep renovation process. 

 

Tools

There are several tools available today to support the implementation of deep renovation in the EU that can support the whole process, from the definition of effective targets according to the features of the building stock to decision-support tools for design at single and multiple buildings level.

 

One of these tools, including all the information about the characteristics and energy performance of the EU buildings, is the EU Building Stock Observatory launched in 2016. This assesses improvements in the energy efficiency of buildings and the impact of this on the overall energy consumption of the building sector. It provides strategic information for the monitoring of renovation strategies and the future implementation of effective boosting measures. Some of the salient outcomes include:

 

  • That the majority of buildings across Europe are used for residential purposes, and that many of them were built before energy performance regulations (which regulate buildings' energy efficiency) started to be put in place in the 1970s. As a result, they are less energy efficient.  
  • That in some countries - including Cyprus, Spain and Ireland – the energy performance of the building stock is relatively high, because a greater proportion of the buildings were constructed after energy performance regulations were introduced.
  • Major renovations are happening slowly. In Spain, Poland, Italy and Sweden, the proportion of building stock undergoing major renovations each year is below 1%, rising to above 1.5% in Germany, France and Austria.

The information included in the EU Building Stock Observatory are strategic for providing general information about the existing stock around Europe and identifying the main renovation needs to be addressed through effective renovation strategies.

 

Another source of useful information that can support the decision-making of renovations is represented by the databases of deep renovation packages. One example of these is the Historic Building Energy Retrofit ATLAS. In this particular case, the tool brings together cases of building renovations that are exemplary both in terms of heritage protection and energy efficiency in historic buildings. The tool shows a set of technical information and performance indicators about the renovation packages implemented in the buildings, allowing for direct access to detailed analyses as a support for designers.

 

Another important database that can support the decision-making process is the STUNNING project that set up a knowledge sharing platform for innovative renovation packages and business models from the main H2020 projects dealing with deep energy renovation.

 

Some others are focusing on the public building stock, and to easy and quickly calculate energy and financial savings in public buildings. Embracing the building stock, the different energy efficiency strategies are commonly applied to building typologies. Effective examples of such approaches are represented by PRIORITEE that provides such functionalities on a web-based tool, and IMPULSE, a GIS-based tool that permits the user to see in a simple way the energy results of gradual energy upgrading investments for groups of public buildings.

 

Once the renovation priority has been defined, the renovation can be effectively managed through innovative BIM-based tools that can either support the overall process from the survey to the energy modelling towards the construction site management, like BIM4EEB, or the technological design, like Open BIM RenoZEB. The second tool helps the users to have a very quick initial cost/performance estimation for the renovation of buildings, based on constructive provisions, technical characteristics and qualities of the project through prefabricated facades.

 

H2020 Projects

Many European projects are currently addressing the need to increase renovation rates. In fact, several of the most recent H2020 calls have made emphasis in this topic (e.g. LC-SC3-EE-1-2018-2019-2020, LC-SC3-EE-2-2018-2019, LC-SC3-EE-4-2019-2020).

 

The P2ENDURE project aims to improve the availability and performance of energy saving solutions for deep renovation and the transformation of vacant, obsolete or sub-optimal public buildings into dwellings. The project provides Plug & Play solutions which are ready to implement, affordable, 50% faster from production to on-site assembly, scalable and adaptable (in all European countries). The main innovation of P2Endure comprises PnP prefab systems enabled by 3D printing, laser and thermal scanning integrated with Building Information Model (BIM). The promoted solutions are SME-driven and geared to rapid and low-disturbance on-site assembly processes for deep renovation.

 

The 4RinEU project, launched in October 2016, will define robust, cost-effective, project-specific tailorable deep renovation technology packages, supported by usable methodologies feeding into reliable business models. It will minimise failures in design and implementation, manage different stages of the deep renovation process, from the preliminary audit up to the end-of-life, and provide information on energy, comfort, users’ impact, and investment performance. The 4RinEU deep renovation strategy is based on 3 pillars; (i) technology (driven by robustness) to decrease net primary energy use (60 to 70% compared to pre-renovation), allowing a reduction of life cycle costs over 30 years (15% compared to a typical renovation), (ii) methodology (driven by usability) to support the design and implementation of the technologies improving the information flow and knowledge sharing among stakeholders to sustain participative design, ensuring to halve the current renovation time, and (iii) business models (driven by reliability) to enhance the level of confidence of deep renovation investors, increasing the EU building stock transformation rate up to 3% by 2020.

 

The StepUP project will develop a new process for deep renovation for decarbonisation, with fast design to operation feedback loops to minimise the performance gap and optimise investments. The project will deliver Plug & Play technologies for minimal disruption, interconnected for maximum impact on energy, costs, IEQ and user comfort. The new iterative approach to renovation, based on big data for continuous performance improvement, will reduce financial barriers and make decarbonisation of existing buildings a reliable and attractive investment.

 

The aim of the REZBUILD project is to develop a refurbishment ecosystem based on the integration of cost-effective technologies, business models and life cycle interactions for deep NZEB renovation to diverse residential renovation typologies and interconnecting building renovation stages and stakeholders. This innovation will establish a multi-collaborative framework within a refurbishment methodology managed by an Agile Project Management tool capable to interconnect in real-time the key steps of a tailored retrofitting plan among all stakeholders involved within the building renovation value chain.

 

The mission of the BIM-SPEED project is to take ‘BIM for renovation’ to a deep renovation level for at least 60% energy saving and to accelerate the market uptake across the EU. In line with its mission, BIM-SPEED aims to enable all stakeholders to adopt BIM to reduce the time of deep renovation projects by at least 30% by providing them with; 1) an affordable BIM cloud platform, 2) a set of inter-operable BIM tools, and 3) standardised procedures for As-Built data acquisition, modelling, simulation, implementation and maintenance of renovation solutions.

 

The Drive 0 project, which started in October 2019, aims to come to a decarbonization of the EU building stock and to accelerate deep renovation processes by enhancing a consumer centred circular renovation process in order to make deep renovation more attractive for consumers and investors and more environmentally friendly. This is embraced by combining the need for a circular building industry with the identification of specific local or national drivers to trigger and to motivate end-users for deep renovation, supported by an anthropology based and environmentally friendly approach to make it customer-centred and respectful of local geo-material areas.

 

In conclusion, because the building sector is one of the largest energy consumers in the EU, deep renovation is needed to cut energy consumption, enhance innovation and improve the general conditions of buildings. Legislation in the EU has implemented the EPBD and the Energy Efficiency Directive to respond to these issues and has required EU member states to adopt long-term renovation strategies. Some challenges, such as high up-front costs of deep energy renovation, are addressed with the support of tools and H2020 projects. Moreover, there are currently many European events which aim to disseminate the advantages of renovation. Some of the most recent are: Renovation Day 2019, Drive 0 Symposium on Circular Renovation, EUSEW 2019.