Reviewing the Energy Efficiency Framework
to generate a window replacement wave

The window, door and flat glass industry welcomes the publication of the Commission’s communication “A Renovation Wave for Europe – greening our buildings, creating jobs, improving lives”[1]. The objective to double the annual energy renovation rate of residential and non-residential buildings by 2030 represents a crucial step toward a Climate Neutral Union and will trigger the transformation of the European building stock as well as create associated green jobs in a post-COVID 19 context, particularly if combined with ambitious national recovery plans with a strong renovation focus.

The window value-chain, which is made of both SMEs and larger firms, plays a strategic role for the sustainable future of the construction industry. The European building stock is equipped with very inefficient windows, mainly single glazed or early uncoated double glazing[2]. By introducing measures in support of window replacements, national Recovery and Resilience Plans have the potential to deliver long-term energy savings and CO₂ emission reduction. We are convinced that the 7 areas of intervention identified by the Commission in the Renovation Wave to scale up efficient renovation and trigger the transformation of the building stock will bring powerful tools to rapidly improve the energy efficiency of European buildings and their windows. To materialize, the Renovation Wave needs to be backed by an ambitious revision of both the Energy Efficiency Directive and the Energy Performance of Building Directive.

Revision of the Energy Efficiency Directive (EED)

Due to the significant share of emissions originating from the building stock (app. 36% of EU emissions), the green transition towards a climate neutral European Union will rely on our ability to renovate the energy inefficient buildings at national level (currently representing app. 75%[3] of EU buildings).

This constitutes a key success criterion to achieve Union’s objective of reducing GHG emissions by 55% by 2030, but also to successfully increase the share of green energies by securing a reduced and stable energy demand.

The energy conversion of European buildings strongly depends on our ability to convert the entirety of the building stock. National Governments and local administrations should show the way and increase the renovation rate and the quality of renovation of schools, hospitals and social housing, in addition to the public-owned buildings, as suggested by the Commission in the Renovation Wave communication.

Energy Performance of Buildings Directive (EPBD)

The Energy Performance of Buildings Directive will remain a key instrument to secure the technical implementation of the EED’s objectives for the building sector. Although several articles have reached an optimal level (e.g. Article 9 on nearly Zero Energy Buildings), some areas of the directive need to be revised to meet the new climate ambitions of the Union and secure that the building sector delivers the expected reductions on greenhouse gas emissions.

The unprecedented level of ambitions set by the Climate Target Plan 2030 requires to prevent all possible gaps between planned and reported energy savings. For the building sector, the most versatile parameter often is the behavioural factor which leads to a well-known “rebound effect”. In many situations, the efficiency of energy saving policies is downgraded by the mismatch between theoretical and actual user behaviour (e.g. a home being heated up to 21°C instead of 19°C, increased light consumption due to poor daylight conditions, additional consumption for air conditioning due to overheating etc…).

To avoid a rebound effect on energy renovation, the human factor and its actual comfort expectations should be considered.

The window, door and glass industry also would like to highlight an important factor to secure the efficiency of energy renovation: the energy balance principle.

Windows and glazed facades enable the intake of free solar gains and daylight, therefore contributing to reduce the heating and lighting needs of a building. Besides, they can also be used to keep buildings cool in summer and mid-seasons by using dynamic solar shading, dynamic glazing, solar control glass and ventilative cooling. Typical requirements are usually merely based on heat losses and are therefore not suitable for the evaluation of transparent components of the building envelope. Modern windows are the dynamic part of the building envelope with changing characteristics and should be regarded as such when setting minimum requirements for energy renovation (e.g. window replacement).

Finally, the strengthening of incentives for private building owners will necessarily remain a major instrument to stimulate energy renovation in Europe. The successful implementation of Energy Performance Certificates, energy audits, and the ongoing introduction of building renovation passports will enable Member States to identify key renovation steps and trigger points for each building of the European stock.

Several opportunities within a building’s lifespan – like the selling, renting or change of building use – are currently missed to embed energy renovation work, and the idea of introducing phased mandatory Minimum Energy Performance Standards (MEPS) will strongly support the energy conversion of the building stock.

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[1] COM(2020) 662 final (link)

[2] As reported by the European Commission in A Clean Planet for all (COM(2018)773:2018-10-28), the average insulation performance of windows in the EU building stock is estimated to be U_W = 3.4 [W/(m²K)]

[3] Buildings Performance Institute Europe (BPIE), 2017 (link)