The restoration of the Notre-Dame-la-grande church

Restoration is the rehabilitation of a building using traditional techniques appropriate to the heritage. Restoration must be reversible, which distinguishes it from renovation, which is a refurbishment without concern for the preservation of what already exists and which may result in a loss of understanding of the building's previous state.

However, prior to the restoration, it is essential to carry out a comprehensive diagnostic study in order to identify the malfunctions and causes of damage and to gain an overall view of the conservation and restoration work to be carried out. Specific studies can be entrusted to specialists (analysis of painted decorations, works of art, furniture, etc.).

Any intervention other than routine maintenance on a listed or registered building or item of furniture must be the subject of an application for authorisation. This application is formalised by a work permit if the monument is listed.

Notre-Dame-la-Grande was listed as a historic monument in 1840, on the first list drawn up by the brand-new National Administration of Historic Monuments. Since then, numerous restorations have been carried out.

Restoration in the 19th century

In 1845, the architect Charles Joly-Leterme, who had been in charge of the restoration of Saint-Savin-sur-Gartempe since 1841, began work on the restoration of the western façade, including the replacement of badly weathered stone with new carved stone.  In particular, the Gothic dais on either side of the central bay were removed in order to restore the Romanesque state of the façade. In 1851, Charles Joly-Leterme was approached by the vicar of Notre-Dame-la-Grande, who asked him to paint the walls and columns of the nave and choir with Romano-Byzantine motifs, similar to those in Saint-Savin. The roof frames and coverings of the nave and aisles were completely rebuilt in the mid-19th century, while the roof frames of the choir and the chapel of Sainte-Anne, dating from the late Middle Ages, were restored to their original state. In the 1880s, Jean-Camille Formigé, head architect of the Department of Historical Monuments, was in charge of the restoration of the church. In 1883, one of the first urgent works was the demolition of Étienne Boinet's chapel, which was in danger of collapsing. Between 1887 and 1890, work concentrated on the construction of a sacristy.

Restoration in the 20th century

The church was the subject of restoration work throughout the 20th century. In 1907 and 1908, the roof frames and the covering of the apse were restored. A campaign of extensive and significant work began in the 1930s. To begin with, the stained-glass windows of the Citoys chapel were replaced with a new stained glass window by Chigot depicting the Tree of Jesse. The 1930s saw a major change in the interior: the plaster was removed from the columns of the choir and those supporting the dome on the bell tower's squinch, a controversial operation. The most important final stage for Notre-Dame-la-Grande was the restoration of the west façade, carried out between 1992 and 1995 under the direction of the head architect François Jeanneau.

The city of Poitiers is taking steps to conserve and restore its heritage, which is protected as a historical monument and as part of the wider framework of the remarkable site of Poitiers (formerly a preserved sector).

This is why the City of Poitiers is committed to keeping a constant eye on its historic monuments, with regular visits to the sites, supplemented by diagnostic studies, as in the case of Notre-Dame-la-Grande.

In 2022, the City of Poitiers entrusted the study for the restoration of the interiors of the entire building to 2BDM Architectes, the head architect for historic monuments.

This diagnostic study programme is designed to:

• Ensure and guarantee the stability, safety and conservation of the entire building
• Preserve and display the painted decorations, furnishings and works of art
• Restore the stained glass windows
• Bring the building up to current standards (fire, electricity, accessibility, etc.)
• Assess the impact of the current heating system on the conservation of the murals
• Lighting of the interior of the building.

The interior of the church has a powdery* surface. The flaking stones, detached plaster, saline efflorescence and white veils on the painted decorations indicate the presence of moisture and salts in the masonry. The cement and plaster coatings in some chapels and the choir are aggravating factors.

* Powdery: characteristic of something in powder form, or of something that can take on the consistency of powder or dust.

Numerous cracks have been observed in all the vaults. The plaster is coming away, indicating a lack of stability, due in particular to the design of the 19th century framework and the increase in the weight of the roofing during the restoration work in the 1980s.

The painted decorations are very dirty or have disappeared under white veils. The entire vault of the choir, a remarkably complete example of Romanesque decoration, is in a dangerous state. The humidity in the church has also affected the furnishings: wooden and plaster sculptures, altarpieces and paintings. The stained-glass windows are sealed with cement, and in some cases counter-sealed, which causes alterations and glass breakage.

The church's technical installations are outdated. The heating, provided by a hot-air generator, is inefficient and detrimental to the conservation of the works of art. The lighting design of the building needs to be completely overhauled as it does not take into account the architecture and its ornamentation and is inappropriate for this site of high heritage value.

• The contracting authority
  The City of Poitiers, as the owner of Notre-Dame-la-Grande, is the contracting authority. It is responsible for defining the objectives and programme of maintenance or restoration work, setting the timetable and ensuring the financing of the project. It selects the project manager and the companies in charge of the site. It is responsible for the overall management of the project.
   
• The project manager
  The project manager is an architect specialising in historic buildings or the head architect for historic monuments. Based on the objectives defined by the client, they carry out the studies and supervise the execution of the work. They help the client choose the contractors. The agency 1090 Architecte is assisting the City with this project.
   
• Companies
  Companies working in the historic building sector have a high level of skill and expertise required to carry out the work. There are no companies approved by the Historic Monuments Service. However, there is a 'Historic Monument' qualification awarded by an independent organisation, QUALIBAT. This is a guarantee of quality when tenders are analysed, but it is not compulsory. Some works require the intervention of specialists (restorers of murals, stained glass windows, etc.). The project owner must also be vigilant in the choice of companies and ensure that their qualifications, skills and sufficient experience on similar sites are adequate.

LOT 01: Scaffolding - Masonry - Stone Cutting
LOT 02: Restoration of painted decorations
LOT 03: Framework – Joinery
LOT 04: Roofing
LOT 05: Stained glass – Ironwork
LOT 06: Electricity
LOT 07: Plumbing

Not yet allocated
LOT 08: Restoration of furnishings

• The DRAC (Direction Régionale des Affaires Culturelles) Nouvelle-Aquitaine
  The services of the Regional Directorate of Cultural Affairs, in particular the Regional Conservation of Historic Monuments, ensure the scientific and technical control of work operations on buildings classified and registered as Historic Monuments. They support the project owner throughout the operation, from the preliminary study phase and the definition of the programme, right through to the completion of the work. The DRAC monitors and verifies the proper execution of the work it has authorised.
   
• The Paroisse de la Trinité
  The church of Notre-Dame-la-Grande, an icon of the city of Poitiers in terms of heritage and tourism, is first and foremost a building dedicated to Catholic worship. Notre-Dame is home to a large religious community. The parish has been involved in the restoration of the church from the outset. In agreement with the parish, the church will be closed for the duration of the work.