Energy renovation of heritage buildings: a guide to understanding the recommendations of the Architects of the Buildings of France

How can you insulate an old building, install a heat pump or add sun protection without altering its architecture? A new interministerial guide provides recommendations to owners, project managers, architects, craftsmen, design offices and departments responsible for processing projects.

Published on July 31, 2026 by the Ministries of City and Housing and of Culture, the Guide to Energy Rehabilitation of Buildings of Heritage Interest was designed and coordinated by the Center for Studies and Expertise on Risks, Environment, Mobility and Planning (Cerema).

This 90-page document focuses particularly on buildings located in designated heritage sites and near historical monuments. Its recommendations can also be applied to the historical monuments themselves, in compliance with the regulations specific to these buildings.

Facilitating the design and instruction of projects

The guide pursues two objectives: to help project promoters integrate heritage constraints from the design stage of the work and to harmonize the practices and advice of the architects of the Buildings of France (ABF) and other instructing services.

It presents the principles applicable to traditional buildings, the regulatory context, available financial assistance, and a project methodology. Several fact sheets then address roof, floor, and wall insulation, window treatment, solar protection, and the integration of heating, cooling, and solar energy production equipment.

However, compliance with these recommendations does not automatically guarantee authorization. Each application is still reviewed based on the building's characteristics, its surroundings, and applicable local regulations.

Adapting shutters and sun protection to local architecture

In a context marked by heat waves and overheating homes, the document gives particular attention to shutters, blinds, and other solar shading devices. The ABF (Architectes des Bâtiments de France) recommends "respecting local heritage characteristics" by choosing the solution based on regional architecture and neighboring buildings.

Solid shutters, louvered shutters or canvas blinds can therefore be preferred depending on the type of facade and the construction practices of the territory.

The Ministry of Culture states its intention to "deconstruct misconceptions and misunderstandings" regarding the supposed systematic opposition of the Architects of the Buildings of France (ABF) to the installation of shutters. While roller shutters are still presented as "a device that is difficult to accept on the facade of a traditional building," the Ministry assures that "there is always an acceptable solution" and that no "proven obstacle" can be generalized.

The Minister for Urban Affairs and Housing, Vincent Jeanbrun, had for his part called for "rapid progress" in the debate between the preservation of heritage and the habitability of cities, on the occasion of the Senate examination of provisions intended to ease the installation of solar protections.

"France cannot become an open-air museum where we admire facades behind which no one can find shelter or protection from the heat." had defended Vincent Jeanbrun on LinkedIn.

Concealing the outdoor units of heat pumps

For heat pumps and air conditioning systems, the ABF (Architects of French Buildings) recommends "the most effective possible concealment strategy" for outdoor units. The guide primarily recommends installing them in a courtyard or on a roof that is not easily visible.

When a unit needs to be placed on a balcony, its integration may involve the use of a box or grille compatible with the composition of the facade and ensuring sufficient ventilation of the equipment.

This section of the guide remains brief, however. It does not provide detailed answers for dwellings lacking an interior courtyard and balcony, or where the roof's configuration and protection do not allow for the installation of outdoor equipment. These situations will therefore continue to be assessed on a case-by-case basis with the relevant authorities.

Exterior insulation should be examined on a building-by-building basis.

Exterior thermal insulation of walls or roofs is another sensitive issue. While this technique can reduce energy loss, it can also alter architectural details, the proportions of openings, roof overhangs, and the appearance of traditional materials.

The guide therefore recommends a preliminary analysis of the building's architectural, structural, and hygrothermal qualities. The aim is to avoid systematic interventions that could permanently alter the facade or disrupt the function of the existing walls.

Depending on the characteristics of the project, solutions may include interior insulation, thermal correction, intervention limited to certain walls, or exterior insulation specifically adapted to the architectural style of the building.

7% of the opinions rendered are refusals

According to data released by the Ministry of Culture, 7% of the opinions issued by the Architects of the Buildings of France are refusals. Approximately 22% correspond to approvals with conditions requiring the applicant to modify their project, while nearly two-thirds are favorable without conditions.