It was a lot like a beauty or talent contest. While the judges in the audience appraised them, the candidates strutted their stuff.

But there was one big difference. The candidates weren't selling themselves, they were selling their Northern Virginia localities as prime locations for economic development.

No one put it more directly than June M. Bachtell, director of Loudoun County's Economic Development Department:

"We have land, land, land in Loudoun County, and what we want to see are buildings, buildings, buildings."

Commercial or industrial buildings, that is, because unlike houses, they tend to pay more in local taxes than they demand in the form of services.

The audience of judges were members of the Northern Virginia Board of Realtors, who were getting a 1981 update of economic development in Northern Virginia sponsored by their commercial and industrial committee.

Real estate brokers, of course, often play key roles in matching a company that wants to move or expand with the right parcel of land. So you can be sure there was some energetic strutting by Northern Virginia localities at last Tuesday's morning and afternoon update at the Tysons Holiday Inn.

Bachtell reminded the audience that Loudoun was developing an impressive industrial base, with nonresidential construction having quintupled -- from #3.5 million to $18 million from 1979 to 1980.

There was Fairfax County Board Chairman John F. Herrity, hearlding "the new industrial revolution in Fairfax County," otherwise known as the boom in electronics-related jobs.

Herrity said Fairfax now has 70 computer firms, 120 in research and 40 in electronics.

Keith Taylor, deputy director of the Fairfax Economic Development Authority, sketched a bullish picture for commercial-industrial activity in the county, with high-technology companies from the area expanding in the county "at a dramatic rate." During 1981, he said, 5 million square feet of office space will be completed or close to finished.

Alexandria Mayor Charles Beatley delivered what turned out to be a 16-page white paper on development in his city which had more statistics than there are gumballs in a machine. And the statistics were just as chewable -- for example, the assessed value of property in Old Town rose from $200 million in 1970 to more than $1 billion in 1980.

Beatly also told the group that Alexandria's aging public housing (about 900 units) will have to make way for new mixed-used development because it stands on "the most valuable ground in our city, mostly in Old Town." Baltimore developer Morton Sarubin, who is rebuilding the 2,150 Shirley-Duke apartments into the spruced-up Foxchase complex, has asked Alexandria to bid on redeveloping all the public housing and creating the new mixed uses.

Beatley stressed, though, that "brand-new replacement units [will be provided] for every one of the present tenants," as required by city law.

From Arlington, there was John Gessaman of the Economic Development Planning Office who stressed that his county was growing vertically, not sideways, as in roomier Fairfax. Arlington is the only Northern Virginia locality to have a functioning Metro line (the orange line that goes from Rosslyn to Ballston), and the county is willing to provide generous densities to developers willing to offer amenities that aren't required.

Even distant Stafford County was scheduled to make a pitch, but its director of industrial development authority, N. C. Sharp, was too busy closing deals on industrial revenue bonds to be at the update.

Next year, no doubt, Fauquier County will be selling its gently rolling Piedmont hillscape as the ideal location for a corporate office park.

Listening to all the salesmanship, it was hard to believe that Northern Virginia is troubled by any of the nation's economic ills.

But economic development in Northern Virginia had moved ahead impressively while housing sales have lagged. The region's real estate industry, judging from the turnout Tuesday, is eager to capitalize on the trend.

The only discordant note was sounded by Northern Virginia's representative on the Virginia Highway Commission, Fairfax businessman William B. Wrench, who said: "We've had public administrators who have been coping with growth for two decades. Now we've got to have selective contraction."

But when Wrench is a man of blunt words, and besides, the only thing he was there to sell was the terrible fix Virginia's roads are going to be in if additional maintenance funds aren't found soon.

When one broker, a quiver in her voice, asked Wrench exactly what he had in mind by selective contraction, he cited the schools. "Twenty-five years ago the population was younger," he said, "and it was concerned with schools and PTAs and such. We've changed, but the educational establishment keeps demanding more. We can't do everything. There are the needs of the aged, too."