Work has begun on Northern Virginia's first regional center for followers of the Bahai faith.

The three-story cylindrical structure will be located along Route 7 in Sterling and was designed by a Canadian architect who has drawn plans for religious structures around the world. The 18,000-square-foot building will have a 500-seat auditorium, classrooms, a library and an information center.

It is intended to serve 18 Bahai communities in Northern Virginia and about 2,500 members of the religion who have been meeting in rented space, private homes and a smaller center in Alexandria.

The Sterling center is one of numerous houses of worship on the outer edges of the Washington region that are being constructed or expanded as thousands of residents with a new diversity of religions have moved to the area.

The project is a testament to the growth and increasing stability of the group in the region, said Simon Zebarjadi, a spokesman for the Baha'is of Loudoun.

"So far, we have not had a place to call our own," he said. "This gives us a sense of belonging. We can serve our friends and guests with more dignity."

Bahaism, founded in the mid-1800s by a Persian man, Baha'u'llah, holds that God's will has been revealed successively by messengers of each of the world's major religions, most recently Baha'u'llah. Its members believe that world peace will be achieved when people recognize that humanity is one race that worships a single God.

The group, which has no clergy, does not hold weekly religious services. Instead, it holds a service and feast every 19 days. Zebarjadi said the function will be the primary regular celebration at the center. Bahais also observe a period of daylong fasting in March and a period that is concluded with a New Year's celebration.

Bahais do not believe in taking donations from nonmembers, so the Loudoun group is raising funds in the community and beyond to acquire the $5 million that the center will cost.

The Baha'i Spiritual Assembly of Loudoun, a nine-person body elected by the county group and responsible for administering the faith's affairs locally, will own and operate the center, but it will hold events and services for members of the faith across the region.

The group has owned the 21/2 acres of land since 1989, when it bought the parcel for $128,000 from a local Unitarian group.

Only recently, however, has the community grown large enough to merit building on the land, said Michael Izadi, secretary for the center.

The group held a groundbreaking in 2002 to indicate to its members that the building would arrive soon, Izadi said. Since then, it has been working to get permits in order and had a ribbon-cutting in May to mark the start of construction.

Construction began in the past two weeks and will take about 18 to 24 months, Izadi said.

"It's a place to worship, but also a place where everyone can come together in the spirit of service and service to humanity at large," he said.

Loudoun has experienced an explosion of new houses of worship. Buddhists are planning to build a temple in Sterling, and the county's first synagogue opened last year. A mosque and Muslim cultural center opened along the border with Fairfax County. Christian churches open frequently, many of which start by meeting in private homes or in schools and then move into permanent buildings.

Neighbors of the new Bahai center, however, have expressed concern about the traffic it will bring to the already congested Route 7 corridor.

The center is being built at the entrance to a small subdivision, and worshipers will be using the same road to enter the building that residents use to drive into the development. That, too, has neighbors concerned, said W. Brad Frank, president of a homeowners association that represents 119 homes near the center.

He said that the Bahais will find tremendous traffic entering and exiting the building and that they may find a different site more appropriate to their needs.

"All I know is, the land is too small, they have a parking issue and it's a real burden on Route 7 for this community and anyone who uses the route," he said.

But Zebarjadi said the neighborhood will find the new center to be a useful meeting place and landmark.

"I'm confident their feelings will change," he said. "We will be very good neighbors. We'll bring love and unity."

Michael Izadi, secretary of the Bahai center, said the group only recently has become large enough to warrant

building on its 21/2-acre lot in Sterling. The center will cost $5 million and be complete in 18 to 24 months.