My Renovation Support Specialist (MAR) is only mandatory for major energy renovations financed by MaPrimeRénov'. When is MAR required? For large-scale energy renovations – several combined works aimed at significant energy efficiency improvements: - A gain of at least two energy performance certificate (DPE) classes. - At least two insulation measures (roof, walls, floors, windows). - Application for the MaPrimeRénov' Supported Pathway. MAR fees: between €3,000 and €5,000. Public aid may cover part of the cost of MAR; the coverage rate varies depending on your income.