A last-minute compromise between feuding factions of the Architectural and Transportation Barriers Compliance Board yesterday averted a vote to do away with the rule mandating that government buildings provide more access for the handicapped.

Yet after the unanimous vote to postpone consideration of the guidelines' fate for six weeks and suspend their enforcement in the meantime, it remained unclear whether the vocal handicapped advocates on the board had succeeded only in postponing the inevitable or had persuaded federal agency representatives to change the guidelines rather than do away with them.

What was clear was that the bitter debates within the tiny federal agency, whose future funding is still in doubt, were suddenly very much in the public eye. Bright television lights glinted off wheelchairs' metal rims as handicapped board members tried to weave through aisles filled with camera tripods and sound equipment.

For more than two years, the 22-member board has been a stage for one of Washington's most acrimonious regulatory debates: how far should the government go in making its buildings and programs accessible to the wheelchair-bound, the blind and the deaf?

During that time, the board was so activist and some members' rhetoric so strident that the board itself became an issue.

The barriers compliance board was given its mandate and a budget now totaling $2.3 million by legislators who thought the four agencies authorized to set accessibility standards--the General Services Administration, the Postal Service, and the departments of Defense and Housing and Urban Development--had not made enough progress, leading different agencies to set different standards. The board was authorized to set minimum guidelines and requirements that the four agencies would have to follow in setting uniform standards.

Four federal members on the board represent the four agencies whose control over the standards had been preempted by the board. Nine of the 11 public members are handicapped; most of them, like Chairman Mason Rose V, are outspoken advocates of maximum accessibility for the estimated 35 million handicapped Americans.

The rule, published in January, 1981, after more than a year's deliberations, covers buildings owned, leased or financed by the federal government. In practical terms, it dealt with such issues as how many parking spaces and toilets should be accessible, how thick carpets and padding should be, whether all or part of a federally financed housing project should be accessible and whether the Post Office's 28,400 leased buildings should be renovated and made accessible every time a lease is renewed.

Board members trying to scale back the rule said that federal buildings are already very accessible; a GSA report estimated the rule's additional requirements would cost at least $800 million annually.

Activists say these figures are inflated and accuse the Postal Service, their chief villain, of willfully ignoring existing accessibility laws. The two factions constantly disagree on statistics and interpretations of law; until yesterday, adjournment was the only issue that could achieve a unanimous vote.

"My bottom line is the most access we can get for handicapped Americans and I don't care whose dollar or whose standard is involved," said Rose, a former pilot confined to a wheelchair since a training accident more than 15 years ago.

"Things can be worked out," said C. Boyden Gray, the counsel to Vice President Bush's Task Force on Regulatory Relief, who has been counseling the board's federal members. "But, like a lot of regulations, the questions come . . . at the margin. You may be willing to do 95 percent of what's possible at a cost of X. But then to do 97 percent costs 10 times X, and to do 100 percent costs a thousand times X."

Even some Carter administration officials found the original rule too sweeping. And when President Reagan took office, board meetings changed dramatically. The 11 federal members, divided in previous meetings, started voting together, almost always joined by Kay Neil, a handicapped housewife from Omaha whom Rose has called "Public Enemy Number One of the handicapped."

In July, this coalition voted 12-to-10 for a proposal to revoke the guidelines; it seemed likely that yesterday's meeting would mark the rule's demise.

But while the factional bitterness was still palpable, the groundwork for a compromise had been laid in a Monday meeting between Rose and Gray. Additional impetus for delaying a decision on the rule came in a letter from eight liberal senators who asked the board to modify the rule's "unduly burdensome provisions" rather than revoke the guidelines.

So the board voted to defer the issue, extending until Nov. 6 the period for public comment. Of the more than 1,500 public comments received so far, most oppose rescission of the rule.

Gray refused to predict yesterday whether the board will eliminate the rule at its Dec. 1 meeting or continue to work toward a compromise. He added that the administration hasn't changed its stand on the agency's future: it would still like to see the board abolished, although Congress appears willing to fund it for at least one more year.