major renovation
as defined in Directive 2010/31/EU of the European Parliament and of the Council of 19 May…, Article 2, point (10) (Definitions)
the renovation of a building where: (a) the total cost of the renovation relating to the building envelope or the technical building systems is higher than 25 % of the value of the building, excluding the value of the land upon which the building is situated; or (b) more than 25 % of the surface of the building envelope undergoes renovation; Member States may choose to apply option (a) or (b).