House-Hunting, Religiously

But she said when Kesher Israel's young people are ready to marry and start families, they usually have to move on to another synagogue or settle for smaller homes.

"They weigh the pros and cons and if they decide remaining at Kesher is more important, then they give up the space," she said.

Settling for smaller homes can be complicated, said Goldstein, who is Orthodox.

She said that observant Jews need large kitchens to accommodate two complete sets of dishes required by religious dietary laws. Some even create second kitchens in the basement to be used during Passover week. Families tend to be large, she said, and they value a big, open dining room where relatives and guests can gather for Sabbath meals.

"The dining room is key," Goldstein said. "Observant families have other special considerations besides location."

Families who can't find suitable homes near an Orthodox synagogue face a long walk to services. But even more problematic, they risk the possibility they've gone beyond the eruv , the symbolic enclosure that surrounds Orthodox communities.

An e ru v consists of an unbroken border of walls and gates. In most areas, telephone wires stretched between poles are the de facto "gates" that define boundaries, but buildings, fences and sea walls can also serve as borders. Where there's a break, the community strings up cord or wire to complete the enclosure.

Once inside, members are able to carry objects, such as a diaper bag, when they walk on the Sabbath and other holy days. They are also permitted to push a stroller or a wheelchair.

Outside the eruv , Orthodox Jews aren't supposed to carry anything -- so they must walk to Sabbath services without so much as a house key.

Unknown to most, the region's eruvim (plural for eruv ) have constantly been changing and expanding in the past few years to encompass larger and larger areas, as housing prices drive members farther from their synagogues.

Kesher Israel's rabbi said he is negotiating with Virginia officials to extend the synagogue's eruv across the Potomac River and into Rosslyn, which is a long but manageable walk.

"More and more people are being forced to move further out," said Rabbi Barry Freundel, a national expert on eruvim . "You build them ( eruvim ) and you have to keep expanding them. The eruv has been in a constant state of change, just constant."