No abstract

The building stock being a huge energy consumer, is an important sector for SDG 11 on sustainable cities and SDG 13 on climate action. Therefore, retrofitting the existing buildings is a priority for most EU countries. Long term goals for the energy performance of buildings are premised. However, to be able to monitor the progress and feasibility to achieve the goals in 2050, knowledge of the actual renovation rate is indispensable. Since years an overall renovation rate of 1% for the EU is communicated. This number is withheld in several countries to stimulate retrofitting (Belgium, Italy, The Netherlands). However, it is not clear how this renovation rate reflects the actual renovation rate and the actual energy savings because accurate knowledge on this is lacking in most countries. This paper focusses on elaborating our knowledge of the renovation rate by analysing its definition and providing a possible, more accurate calculation method. A literature study shows that there is no commonly used definition of ‘renovation rate’ in the EU. Instead different approaches are being used, often depending on available data. A case study for Flanders, Belgium reconstructs the communicated renovation rate of 0.7% to 1% by means of a database of the renovation activity of approximately 6000 homeowners (2012-2018). The used survey concept shows that the actual renovation rate exceeds 1% and is able to provide extra insights on the energy renovation depth in Flanders. In a next step this could be extended to calculate the actual energy savings due to renovations. As this survey concept can easily be adopted in other EU countries, it could form the base of an aligned monitoring of the progress towards a sustainable built environment.

In order to achieve a sustainable built environment by 2050, the European building stock needs to be retrofitted. Also in Belgium, with 75% of the residential buildings built before 1980, deep energy renovation is stimulated. The Flemish government premises long term goals for the energy performance of the existing building stock in the Renovation Pact (2014). To be able to monitor the progress and effectiveness of the Renovation Pact, knowledge of the actual renovation rate is indispensable. Since years, a renovation rate of 0.7% to 1% is communicated as an argument that renovation should be stimulated. However, there is little empirical evidence for this figure and how it reflects the actual energy renovation activity. Furthermore, non-energy renovation activities are considered as possible gate for home owners towards energy renovation, but little is known about these renovation activities. Since 2013, a yearly survey is done by Essencia Marketing, a marketing agency specialized in the construction sector, on the renovation activity of Belgian households. A representative sample of 1000 households indicates their renovation activity in the previous year through an online questionnaire on structural works (façade, wall, roof, etc.), technical works (HVAC, electricity, etc.) and energetic works (insulation, windows, etc.). For the period 2012-2018, the results show that each year almost 2,1% undertakes a deep energy renovation activity (excluding decorative works). To better estimate the energy renovation activity in Belgium, the paper will firstly discuss the different types of renovation works home-owners execute, and determine the share of energy related renovations. This will be confronted with official statistics on (energy) renovation. Then the non-energy renovation activity will be discussed to determine the share of renovations that could serve as a gate to promote deep energy renovation. This could inform policy makers on policy actions to stimulate combined renovations.