Relocating is like asking to be part of the chosen few again, to be one of the happily housed. It requires the strength and optimism to shed the familiar and the stoicism to handle the interim anxiety.

The interim anxiety. Maybe that's where the short-term-lease market gets one of its other names--interim housing. These short-term apartments, also called corporate housing, are firmly established in the Washington area and offer a variety of services for people on the go--or, rather, on the short-term stay.

Corporate housing refers to contracted stays of 28 days or more in apartments or houses rather than in hotel rooms. It is a thriving business that has been growing more rapidly than other types of lodging, specialists said.

Corporate housing generally means larger accommodations at a lower rate than a hotel room. It also seems to take on two distinct forms: An interim-housing company can own an apartment building dedicated to the short-term renter, or it can be a firm that owns houses or holds leases in a variety of apartment buildings and re-rents them, as a third-party leaseholder, to short-term residents.

According to several people in the business, corporate housing companies in Washington cater to a range of clients, including government employees here for training; international businessmen and embassy personnel; Americans returning home from overseas; and families relocating to the Washington area and hunting for the perfect house in the area.

Given the variety of apartment and house situations assembled by corporate-housing companies, tenants can generally stay in the location of their choice, whether in an apartment, a town house or a single-family house. The major interim players can find pet-friendly buildings for their clients and child-friendly communities.

How big is a short-term accommodation? That's up to the client. What kind of amenities are offered? They vary widely from company to company, and sometimes from building to building, but all companies offer fully furnished apartments, housewares, customized items upon request and a variety of services.

To add to the convenience of this type of lodging, all expenses, from cable to phone bills, generally are combined in a single invoice.

California-based Oakwood Corporate Housing, the largest company in the business, has about 1,400 units in the Washington area. In some buildings it operates as a third party on lease agreements, but also owns and manages five local buildings in Arlington, Alexandria, Falls Church, Gaithersburg and Baltimore.

"Having our own product means a lot," said Dianne Bonanno, Oakwood's regional marketing manager. "We are there all the time, and we have more control of things."

Oakwood's standard package includes most kitchenware, linens and furniture, but clients have other options--from the Asian Cooking package, which includes a wok, to the Kids Package, which includes a night-light and cartoon-themed linens, among other items. Nationally, Oakwood charges on average $60 a night. Housekeeping is optional and paid separately.

Stephanie Liller, Oakwood Arlington general manager, said some tenants at the 1550 Clarendon Blvd. building just want things working properly, but people who stay longer develop a connection with staffers, usually inquiring about the best bank branch, the tastiest pizza or how to program their videocassette recorders.

She especially remembers a tenant, relocating from Puerto Rico, who arrived with his wife and two children during the 1996 blizzard with no heavy coats. "A sales representative picked them up at the airport and drove them straight to the mall to buy winter coats, and then delivered them to their corporate apartment," Liller said.

Another major corporate housing player with a strong presence in Washington is ExecuStay by Marriott, based in Gaithersburg. With 6,500 units nationwide and about 450 in Washington, ExecuStay operates exclusively as a third-party lessee. "Guests can truly select their location," spokeswoman Dee Dee Dochen said.

A night in an ExecuStay apartment in the Washington area costs about $80. The fully furnished apartments can be customized and weekly housekeeping is included.

Marriott's also maintains two extended-stay lodges, Residence Inn and TownePlace.

Smith Corporate Living is another solution for people on the move who are looking for a down-home type of feeling. The company owns 16 buildings in Northern Virginia and the District and operates elsewhere in the area as third-party lessee, offering about 1,000 units in the region.

Being smaller than the other companies in the business, Crystal City-based Smith Corporate Living focuses on its strong local presence and on customer service. "You must get close enough to a relocating family or a business traveler," Vice President Larry Guest said. "You must be able to deal with them as individuals."

On average, a night in a Smith Corporate Living apartment costs $92, which includes newspaper delivery, coffee, membership in local health clubs and housekeeping.

BridgeStreet Accommodations also competes in the corporate housing market in the Washington area. With more than 300 units in the region and 6,000 units elsewhere, the Ohio-based company works exclusively as a third-party lessee in the District, Maryland and Virginia. On average, BridgeStreet tenants pay $85 a night.

Before arriving at a BridgeStreet apartment, a tenant receives a package containing the key to the unit, a local map with directions to the apartment and a guide to area services, such as a dry cleaners or local pizza delivery restaurant.

BridgeStreet's World Bank clients recently got free membership in a local health club, company spokeswoman Rita Pesecky said. And upon request, clients can not only customize their furniture and utensils but also ask for special items, such as children's furniture or equipment for a home office.

Analysts said there is high demand for corporate housing, in part from companies seeking to attract or retain qualified employees in a tight job market. Then there's employees' high mobility. "There are a lot more employees spending work time in different parts of the country," said Manuel K. Pyles, an analyst with A.G. Edwards & Sons Inc. of St. Louis.

Corporate housing "is a more attractive lifestyle for the employee, no matter how nice the hotel," Pyles said.

It's also cheaper. D.K. Shifflet & Associates, a lodging research firm based in McLean, said last year's average rate for a standard hotel room was $78, compared with $71 in an extended-stay unit.

Corporate housing also shows a fast-growing pace. According to a 1997 report by Mark Hughes of SunTrust Equitable Securities of Nashville, demand for extended stays increased at 12.3 percent a year from 1994 to 1997--almost three times faster than the lodging industry average.

CAPTION: At the Oakwood complex in Arlington, general manager Stephanie Liller shows off a one-bedroom apartment that offers most kitchenware, linens and furniture.