In the federal government, where size IS important, the bureaucratic Mr. Big whose ego resides in his massive Chippendale desk and a Sahara like expanse of carpet should be warned that time and space and something called "systems" furniture are closing in on him.

In the new science of space planning, the target is not outer space, but federal office space, and the question is how many bureaucrats can be happy in functional adjacency.

"We're beyond the point where we can use space to express somebody's rank. We can't afford it any more," said Rick Hendricks an engineer who gravitated into space planning, and a leading avengelist of the new system for the General Services Administration (GSA). His office directs the assignment and use of space for the government nationwide.

Hendricks and other space planners preach a gospel that they say could save taxpayers millions of dollars, and one that reveals much about the changing rhythm and symbols of government work.

To keep up with the increasingly frantic page of reorganization musical chairs and soaring real estate costs, bureaucratic furniture will be climbing the walls, if the plan works out, and the walls themselves will be as movable as the rest of the feast.

In systems, which refers to furniture that hangs from the wall instead of taking up floor space, even the traditional government file cabinet becomes airborne, stretching languidly along a wall like a bookshelf, with a plaid fabric door, instead of hulking grayly toe to toe with its siblings.

"More space will no longer necessarily be better," Hendricks said. "In your kitchen, you don't want your stove 50 feet away from your refrigerator."

"What, then, will separate the boss from the flock?

"A chrome strip, a higher-quality wood veneer maybe, a chair with a higher back and a swivel mechanism that the others don't have . . . Look at the military. They can live in squalor because they put their status right on a guyhs shoulder."

With plush and plastic systems furniture, a GS15 manager who now takes up 225 square feet can be reduced to two-thirds of that, and a lower ranking employe who now gets 100 square feet can fit nicely into 40 square feet, Hendricks said.

"If he's real bureaucrat," a manager's traditionally furnished office has not only a huge desk but "a long, T-shaped table, six chairs, a couple of couches, an end table, a dictionary stand, a coat rack-in other words a bunch of things filling up the floor," Hendricks said.

In the Connecticut Avenue showroom of one of 17 contractors on GSA's list of systems furniture suppliers. Hendricks demonstrated the latest in manager's offices: a sleek but modest desk overhung with ranks of shelves; files up the wall and, close by, a modest oval conference table for "more flexible interaction" than the T-model table.

"Most managers are talkers, anyhow. They read, sign and talk. They don't do a lot of writing," Hendricks said.

Later, he and a GSA personnel manager sat over a blueprint of a gutted wing of their* old building, deciding the fates of several hundred employes who are about to get religion.

With the sweep of a Magic Marker the raised statuses, lowered perks, gave a window here, added a shelf or tock away a foot or two there, gave a high wall panel, or a low partition.

Hendricks and other GSA space scientists spoke with fervor about the importance, long-ignored in their view of space planning.

"Space is the body language of the office the silent language for politics, power, intrigue, inability to function-all the things people won't say in any other way," said Lawrence W. Vanderburgh, formerly a space management consultant, now with GSA.

"Managers often try to get us to solve what are really their personnel problems," he added."They tell us it's a terrble space problem when they really mean it's a bunch of disgruntied secretaries who don't want to answer the phone at lunch."

Ever mindful of their "federal fishbowl" situation, the specialists said they intend to implement the new system cautiously and gradually, as the old furnishings wear out, encouraging competitive bidding by suppliers and making sure the whole thing is cost effective , case by case.

True, the new furniture is not cheap, and the government will spend $9 million this year for the new systems, as it converts about one million square feet of office space, Hendricks said.

"But that should give us a savings of $30 million in rent costs over the life of the furniture-so after three years, we're getting back a bonus."

Time is an added dimension of the space problem, caused by the government's constant amoeba-like splicing and merging of itself into new shapres.

"With the government reorganizing about every five minutes, we spend $240 million a year tearing down walls coordinating a bunch of construction trades, changing electrical wiring just to move offices around," Hendricks said. "We change about 8 or 10 perent of our space each year.

"This new stuff you can rearrange over the weekend. It's like a tinker toy set, where you can switch the parts around, fit them together to suit yourself."

Hendricks says the new systems furniture could cut those costs in half. Moreover, it would give agencies a certain desirable independence from GSA, he added.

"GSA is not known for being the greatest responder. It can take three, six, nine months to get a move organized and by that time, they're likely to need some different space."

As it is, when an agency needs to move in something of a hurry as in the case of DOE, Hendricks said, "We use what we call an 'insertion plan,' just to get the people in there fast. It's sort of like force feeding a goose to produce pate de fois gras, although what comes out it not pate."

In one especially controversial move, GSA officials were criticised when they had to pay $3 million in rent on an office building which stood vacant for a year. Located at unglamorous Buzzards Point in Southwest, it was shunned by a succession of federal agencies who labeled it a turkey.

"What nobody realized was that the government actually saved money on that deal," Hendricks suggested. "We had requests outstanding for two million square feet of space from Various agencies. State, Treasury, Securities and Exchange Commission, Agriculture . . . We offered them all Buzzards Point and they all decided they could live the way they were for another year.

"We held off the growth of government for a whole year. When you look at it that way, at $7 a square foot, we saved $14 million in added rent costs."

While political and economic pressures have forced the government to keep a lid on the number of federal employes in recent years, as GSA space official James Whitlock put it, "Every time somebody reconfigures, they add more space to make the personnel they do have more efficient."

That means more space for the Xerox machine and other equipment, and more conference rooms in which to train and retrain the existing work force, he said.

Something like 80 percent of the government's offices around the country still have the long corridors, flanked by cubicles walled in solidly by plaster and wallboard and traditional heavy horizontal furnishings.

These offices are better suited to the kind of work the government was doing 75 years ago, before "word processing" machines, computers and the paper explosion, GSA officials said.

Today, planners prefer hugh open expanses within which people and things can be shifted into working clusters to suit constant change.These clusters should provide what one GSA manual calls "functional adjacencies," which means they should take into account the flow of paper work, office politics and personalities and other practical considerations.

Even in newer buildings with wide open spaces built in, however, the bureaucratic mindset has insisted on dividing the territory into little "cells" of empire, Hendricks said. He named the headquarters of the departments of Labor and HEW as the worst examples of that.

Part of this was the fault of a failed predecessor of system furniture, known as "landscaping," he said. Landscaping furniture was so light and flexible that "people just picked it up some midnight and moved it on their own." The result was a confusion of "rabbit warren" feifdoms in which, he said, "people get lost."

Systems furniture has the advantage of being interlocking, and somewhat sustantial, so that it stays where a manager puts it, he said. Yet it is more "people oriented," providing a degree or privacy and individual control.

Hendricks' own office is a bit behind the times-done in a sort of modified landscaping called a "rectilinear open plan, geometric." But the most important thing is, as he pointed out, "we just got rid of the last traditional desk." He uses a "more democratic" round table.

For federal workers, the handwriting is on the wall, and the wall is coming this way.