Bushey Synagogue will relocate to nearby Immanuel College for services over the summer months to facilitate a £1.2 million refurbishment of the shul.
A total revamp of the main building is due to start in May and finish in November. To minimise disruption to synagogue events, the building will not close until the majority of activities have ceased for the summer.
On completion, the congregation will gain new toilets, cloakrooms, offices, carpets, flooring and lighting.
The recession scuppered plans for a £6 million redevelopment of the synagogue site. As well as the main shul, the complex also incorporates two buildings which together function as a community centre used by 2,000 people a week. The reconstruction was intended to expand both the synagogue's seating capacity and the site's usable space by 125 per cent.
Bushey chair Paul Mendelsohn said that at an EGM in September, members agreed that "rather than wait until we could afford go ahead with the redevelopment, it was better to proceed with an extensive refurbishment of our old buildings.
"A substantial part of the cost has already been met through donations and surplus funds."