The history of the building that houses the Mont-Cauvaire town hall today spans more than a century and a half. Its origins date back to 1845, when a dispute arose between the communes of Clères and Mont-Cauvaire regarding the parsonage at Le Tôt—a formerly independent commune that had become a hamlet of Clères in 1826. This building housed the parish priest responsible for Mont-Cauvaire, Le Tôt, and Cordelleville. Deeming the residence too far from the church in Mont-Cauvaire, the *Conseil de Fabrique* decided to build a new one closer by, in Mont-Cauvaire itself. To raise the necessary funds, the old parsonage was sold at auction on 25 September 1849 for 6,000 francs to Mr Riqueur, owner of the La Chapelle mill in Le Tôt.
The commune then provided a plot of 25 ares near the town hall and school for the new construction. On 10 February 1850, the contractor Antoine Lerue won the contract, and the works were signed off by the Rouen architect Mr Desmarest. The first occupant of this new parsonage was Father Fauconnet, a highly esteemed clergyman affectionately called "our good father curate" by his female parishioners. He led an active life there alongside his sister, Mademoiselle Domérie, and his nephew Raoul, a prominent figure in the socialist circles of the time. The priest also received regular visits from his friend Eugène Noel and the village’s bachelor schoolmaster, Mr Cardon.
Following the death of Father Fauconnet in 1881 and the tenure of Father Brubert, other priests followed. At the beginning of the 20th century, under the leadership of Father Sanson, the parsonage required significant repairs funded by the commune, and an eighteen-year lease was signed on 10 March 1907. Father Glatigny took over in 1909, with leases successively renewed in 1917, 1927, and 1933. In 1951, the rent was set at 570 francs to cover the taxes and insurance paid by the municipality. However, a major turning point occurred at the end of 1968: the diocesan administration did not renew the lease, as the appointment of a new curate to the commune had been definitively ruled out. From 1 April 1969, the building was let on a temporary basis to assist young local couples awaiting permanent housing.
On 24 October 1974, the municipality informed the tenants that it would repossess the premises at the end of the year to transform them into a town hall with residential accommodation—a project approved that December. This project, costing 91,787.54 francs, was financed by a loan, communal funds, and a grant from the Ministry of the Interior, and was completed in November 1976. During the 1980s, the first floor of the town hall still served as temporary housing for residents.
The edifice continued to adapt to growing administrative needs thereafter. In 1987, a restructuring plan was adopted, followed in 1989 by a project to extend the offices on the first floor and convert the loft for the archives. Finally, to meet modern standards, works to enlarge the town hall and the village hall for PRM (persons with reduced mobility) accessibility were voted for in October 2018 and completed in 2020.