As an addition to the “Energy performance certificates and minimum energy standards” section, another form of assessment should be mentioned: the energy audit created by Article 8 of the EU Energy Efficiency Directive. As a mandatory obligation every four years, this has been implemented in the Flemish Region (mandatory for large enterprises subject to an environmental permit or notification system), in the Brussels-Capital Region (mandatory for certain large enterprises and for large energy consumers if they request (a renewal of) certain types of environmental permits) and in the Walloon Region (mandatory for large enterprises).

From 1 January 2023, every house that is sold in the Flemish Region with only an E- or F-label, according to the required EPC, needs a green retrofit within five years, in the absence of which a heavy fine will be imposed by the Flemish Agency for Energy and Climate.

Roof insulation is also made compulsory to the R-value of 0.75 kilowatt-hours per square meter. When Flemish housing inspectors notice that this insulation is not provided for, a severe penalty of 15 points will be given. This may lead to an interdiction to use the house, following a procedure before the local authority.

For the moment, the Walloon and Brussels-Capital regions do not foresee mandatory green retrofit, but the Brussels-Capital Region is working on it because it wants every house to reach EPC level C by 2050.

Most notably, since 2006 the Brussels-Capital Region has also encouraged private and public actors with a large real estate portfolio to develop and implement their own Plan for Local Action for the Use of Energy (PLAGE) program. PLAGE aims to create a tailored “energy culture” involving all employees, suppliers, clients/visitors, etc., for the institution or organization. The coordination of the whole program is entrusted to an appointed energy coordinator (energieverantwoordelijke). A PLAGE program has been mandatory since 1 July 2019 for all public services with a building surface area of over 50,000 square meters and for private services within the region’s territory with a building surface area of over 100,000 square meters.

For natural persons, the Brussels-Capital Region offers a range of subsidies and even an interest-free loan for energy-saving investments (including studies, smaller works, renovations and new construction projects), with conditions that vary depending on the applicant’s socioeconomic position.

For companies, the Brussels-Capital Region also has a range of financial support mechanisms, depending on the size of the company (e.g., SMEs) and the type of investment: subsidies and tax reductions for energy-saving investments (including studies, smaller works, renovations and new construction projects), help from the “facilitating agency for sustainable buildings,” support for investments in renewable energy production, soil depollution, and a broad range of sustainable projects (e.g., eco-construction, circular economy, waste management, etc.).

The Walloon Region offers natural persons subsidies that are revised annually (primes énergie 2015), and which increase depending on the applicant’s socioeconomic position, for roof, wall or floor isolation works, installation of efficient heating or boiler systems, and energy audits.

For public services and not-for-profit organizations, the Walloon Region offers an energy-saving subsidy program called AMUREBA (previously UREBA). Investments for which subsidies are offered include works that improve a building’s energy efficiency, energy audits, feasibility studies for installing certain technologies and energy accounting studies.

For companies, the same AMUREBA program (previously AMURE) also offers an energy-saving subsidy. Currently, subsidy programs are only offered for energy accounting studies, energy audits and obtaining the technical approvals necessary for a product or system to be accessible on the market.

All three regions award “green power certificates” to companies or households that are connected to the grid and autonomously produce electricity from renewable sources. This green certificate is a financial aid granted by the region when installing these energy sources. However, both the Walloon Region and Flanders reduced the scope of these certificates to large installations only and, in parallel, introduced different complementary financial aids (such as the “call green power” in Flanders). Separate calls for project-based support are launched regularly.

Finally, many municipalities and even some provincial authorities also offer local financial stimuli for certain types of energy efficiency investments.