Borehamwood and Elstree United is using the newly-opened synagogue at Yavneh College for weekly Friday night and occasional Shabbat morning services for a satellite minyan.
The move follows the signing of an agreement between the US and the school.
It is a further development of the Friday night minyan launched 18 months ago to serve members of the congregation who live on the southern side of its catchment area. Held in private homes, the services attracted a core congregation of two dozen.
Synagogue minister Rabbi Naftali Brawer led the first service at Yavneh and will continue to officiate on an occasional basis. "There is no doubt," he said, "that the area is home to an increasing number of our congregants, especially those with young families. I believe many more of them will be drawn to join the services, not only by the convenience but also by the beauty of the Yavneh shul."
The shul, which will be formally consecrated later this year, was also used for additional Borehamwood Rosh Hashanah and Yom Kippur services.
In Mill Hill, meanwhile, the local United congregation took over the premises of the Mathilda Marks Kennedy School to accommodate 200 members at extra overflow services during the festivals.
The congregation now totals around 2,000 and the number is rising. Seating problems should ease once the projected £3.5 million redevelopment of the shul is completed. But as the 12-month building programme has yet to start, many members may still find themselves in temporary accommodation for the 2009 festivals.