Maidenhead Synagogue is opening new facilities this summer to keep up with the demands of a rapidly expanding community.
Ongoing construction is the third project in three decades for the Berkshire Reform congregation, whose membership of 821 families has raised more than £500,000 to fund more outdoor spaces and a dedicated youth area.
There will also be extra space for the 184 children who attend its religion school.
Rabbi Jonathan Romain said that a significant percentage of the community had donated to the development. "Some have given small, some have given big.
"There are retired people who have given £100 and one individual who gave £25,000. It's our new synagogue and that proposition makes all the difference."
The rabbi added that as well as the prospect of Crossrail linking Maidenhead directly to central and east London, the shul also benefited from being "at the cutting edge" when it came to attracting young families looking for a Jewish life close to the capital.
This had been achieved by creating a congregation with a pluralist outlook. "We have a very broad definition of being Jewish, so there are services. But we've also made an effort to brand ourselves as a community centre, not a house of prayer.
"I don't mind if they come to a Shabbat service, to the film club on Sunday or to the Zumba club on Tuesday. It's about being part of the extended community in whatever way they want.
"That's one of the reasons we've grown."
The rabbi urged other communities to follow suit, explaining: "It's about recognising that Jewish identity is flexible and fluid.
"I'm sure that's the future of being Jewish and synagogues need to facilitate that."