The directive requires EU member states to renovate at least 3% of the total floor area of building of more than 500 square meters which are "owned and occupied by their central government".

Although these buildings represent just 12% of the EU's building stock, the European Commission believes this should set the example for private owners, creating a snowball effect.

Adam McCarthy, Director of Government Relations at Johnson Controls and President of EuroAce, representing companies in the building-efficiency sector, said that for every €1 million spent on building regeneration, "you create 19 jobs in and around the construction industry, building or supplying equipment.”