Maybe you've noticed them and done business there -- rows of somewhat glamorized little warehouses that look like mini-retail shops in modular cluster arrangements.

For openers, you can stop at BuildAmerica III in Tysons Corner and find a place to buy a $75,000, 80-year-old, hand-made Iranian rug. Next door you can buy a skylight, an accordion door or a movable partition. Nearby you can do your physical fitness thing, buy feed for a dog or an elephant, find several kinds of furniture, kitchen cabinets and counters, atuo parts, knick-knacks, specialty woods and wood products, television sets, signs, solar heating systems and custom building products.

Originally designed and marketed to provide warehouse space, these clusters of masonry bays are now showing up here and elsewhere in the country as gussied-up retail and small business outlets that attract shoppers for somewhat specialized products to back-street locations. Some occupants offer services; others offer products.

And the scene is changing. Instead of being basic storage space or a place for servicemen or cottage industry persons to do their things and store their gear, the condominimum warehouse cluster now shows up with attractive orange awnings and individual identifications of the occupants. Custom use is the key.

John R. Pflug Jr., a Northern Virginia builder, has been in the forefront of condominium warehouse development. He has completed four BuildAmerica condominimum warehouses, including the one at Tysons. Two are in the Fullerton Indistrial Park below Springfield and the fourth is in the Merrifield area. Pflug sold more than half of the 30-by-60-by-16-foot spaces to occupants. The others he leases with an option to buy.

BuildAmerica Five, the largest with 89 spaces, is under way on 11 acres in the Shell Oil Industrial Park near I-395 and Edsall Road. Now Pflug is a partner in the $7.4 million project with Clover Development Corp. and Internatinal Developers Inc. Nearly half of the bays in the first section are sold and the second section will be started later this year. Prospective users include furniture outlets, a heating and air conditioning contractor and a clothing outlet.

The BA Five site, in an industrial park, is near separate locations of Marlow Furniture, Public Broadcasting System and Prudential Life Insurance Co.

Pflug pointed out that each warehouse bay contains 1,800 square feet under a 16-foot ceiling. Individual units have a 10-by-10-foot steel overhead door and a conventional door for people passage. Each unit has a small toilet, a drinking fountain and a service sink. Water and electricity are individually metered. Units sell for $81,500, or $45 a square foot. Leases are granted to non-buyers at $6 a square foot, with incentive options to purchase later.

Design flexibility is strategic to the appeal of the BuildAmerica bays. In addition to the option of buying or renting, the occupant can have just one unit or also take the one in back -- thus have openings at two ends of the tiered units. Or the user can take the identical unit next door and connect them by opening up an architectural "knockout" wall, built with framing to make the opening structurally feasible.

Floors are concrete and walls are cement block with bar joists. Pflug said that some occupants have spent as much as $25,000 on improvement. One back-to-back occupancy has three separate businesses. Father-son John and Anthony Porto have Stonehenge Builders, Laminates Unlimited Kitchen Gallery in their customized double space. Like some other users, they have created their own second story (possible because of the 16-foot ceiling) within their space.