As part of the Recovery Plan, the restoration of Saint-Arnoux Cathedral was able to be done by combining conservation of a historic monument and nesting spaces of protected bird species.

Emblematic monument of the Hautes-Alpes, the Saint-Arnoux cathedral, located in Gap, was built at the end of the 19th century according to the plans of architects M. Laisné and M. Goulain. Consecrated in 1895, it was declared a historical monument on August 9, 1906.

Portail et parvis de la cathédrale St-Arnoux
Affichage Plan de Relance - Cathédrale St-Arnoux

Yann Visseaux, Heritage Engineer in charge of the department of Hautes-Alpes and Emilie Avizou, in charge of the Recovery Plan, both agents in the Regional Conservation of Historical Monuments of the Regional Direction of Cultural Affairs Provence-Alpes-Côte d'Azur (DRAC PACA) provide us with some details on the ongoing work and the impact of the ecological approach on the protection of nestings.
The restoration of the roofs will allow to put out of water the cathedral and thus to protect its structure from degradation and embrittlement that could be accelerated by the contact of water, gels and by consequence to ensure the safety of the public.
The initial date of the start of construction was postponed following the completion of an ecological diagnosis attesting the presence of protected bird species (rock and window swallows, swifts, kestrel falcons) in the immediate environment of the cathedral. In order to preserve nesting, the DRAC PACA called on the Ligue Protectrice des Oiseaux (LPO) to consider so-called compensatory measures, having the least possible impact on the existing ecosystem.


'We knew there were protected species on the site. The LPO was quickly contacted so that we could find alternatives. The representatives accompanied us in the preparation of the application for exemption from the prohibition of the destruction and disturbance of habitats of protected individuals and species. '

After work in 2010 (consolidation of the vault of the choir and interior of the chapel Saint-Arnoux), a diagnosis in 2014 revealed the need for restoration of facades and covers. After the facades, there remained the covers whose restoration, slightly initiated, was confirmed by the arrival of the Recovery Plan.
The mastermind of this project is Michel Trubert, Chief Architect of Historical Monuments territorially competent. Two phases of work are planned:
• A firm slice covers the nave, transept and aisles
• An optional slice concerns the bedside.
The appropriations received to carry out this operation amount to EUR 1.4 million.

Portrait of the recovery: Saint Arnoux Cathedral in Gap (05)

Vue du chantier, côté sud-est - Cathédrale St Arnoux
Protection of the species present on the site, intervention of the LPO

By ministerial incentive, biodiversity must be taken into account when renovating and restoring historic monuments. There are more and more examples, and in our region as well.

Can the species present in the building not be detrimental to its structure and conservation?

This is always the problem, there are always several regulations and concerns that intersect. Indeed, bird droppings can alter the stone. We must cross paths and take sides. A balance must be struck between preserving the site and preserving the species.”

In the case of the cathedral of Gap, due to the presence of protected species (swallows of window and rock, black swifts, kestrels), a derogation to this protection (prohibition of destruction and disturbance of habitats) is required to perform the work. A number of recommendations have been imposed by DREAL, the instructor of the exemption application file: reduction measures (access to natural nests, artificial nest boxes and reconstruction of nests), compensatory measures (replacement of nests and creation of nesting site of black swifts) and accompanying and monitoring measures (study of bats, ecological accompaniment during the work and monitoring at the end of the work).

Arrêté préfectoral du 11 avril 2022 portant dérogation à l'interdiction de destruction et de perturbation d'habitats et d'individus d'espèces protégées dans le cadre du projet de restauration et des couvertures de la cathédrale Saint Arnoux à Gap

pdf - 341 Ko


Nichoirs artificiels sur échafaudage
La Ligue Protectrice des Oiseaux: interview with Valérie Vincent and Michel Vergès

Valérie Vincent and Michel Vergès, active members of the association LPO PACA, intervening in support and advice to preserve biodiversity in the city on the site of the Saint-Arnoux Cathedral of GAP, lent themselves to our questions.

"The installation of temporary nesting boxes for swallows is a first in France. We hope that this project initiated by the DRAC PACA will serve as an example and springboard for others.'

Nichoirs artificiels sur échafaudage - Cathédrale St-Arnoux
Bacs d'argile mis à disposition des oiseaux pour leurs nids