The House of Representatives killed a controversial plan yesterday to extend the West Front of the U.S. Capitol, voting by a surprising 3-to-1 margin to restore its decaying facade instead.

The 325-to-86 vote came after two hours of sometimes bitter debate in which one speaker decried the $70.5 million extension plan as a move "to clutter up the Capitol with restaurants and latrines."

Instead, the House voted to spend $49 million on preserving the West Front, which has so eroded over the years that a 16-foot section of sandstone toppled from it last month.

The vote reversed the sentiment of the House Appropriations Committee, which voted last week to spend $70.5 million to extend the West Front about 31 feet toward the Mall.

A Senate subcommittee, meanwhile, pared a plan to restore the West Front from $66 million to $48 million. Yesterday's measure next goes to the Senate.

Proponents of the long-pending extension measure charged that it was needed, in the words of Rep. Bob Traxler (D-Mich.), "to fulfill the manifest destiny of the Capitol building." It would have provided 147,000 square feet of office space--much of it in hideaways for senior committee chairmen--plus a public restaurant, restrooms and a visitor center.

It was the fruit of about 20 years of study and of plans by George M. White, architect of the Capitol who, his supporters declared, had devised a scheme that would actually preserve the West Front even better by making it an interior wall.

The $70.5 million proposal was "a very modest design," said Rep. Vic Fazio (D-Calif.), which "accents and complements the Capitol dome.

"This is a living, breathing, changing building," Fazio said. "A constantly evolving monument to the American people."

He and other pro-extension forces charged their opponents with the sort of architectural obstructionism that would have frozen the building in time without indoor plumbing.

Rep. E. Clay Shaw (R-Fla.), said the Capitol should not be "a shrine to the architect of the Capitol, but a monument to the American people," and said White's record in controlling costs "was hardly a track record to inspire confidence."

In an action last week that White termed "an inadvertent oversight," Shaw noted, White had acknowledged that the six-year-old extension plans would have to be redrawn because they would have so crowded the Capitol's historic west terraces that only a seven-foot walkway would have remained.

Yesterday's vote reversed long-traditional House support for more space, and came despite reminders that senators and their staff enjoy more than twice the square footage per person of the House.

Rep. Samuel S. Stratton (D-N.Y.) said the issue was not one of space but of money. Congress had no business indulging itself, he said, "at a time when we're taking food stamps from the elderly." He said one example of indulgence, the Hart office building, should already be "a substantial embarrassment to this body."

While no definite plans exist for restoring the existing West Front walls, some sentiment was voiced yesterday for covering them with marble in place of the sandstone that has cloaked them since the Capitol was first built. Engineers have suggested it will first be necessary to drill hundreds of holes in the sandstone and install reinforcing rods of stainless steel. The process is expected to take about four years.

Yesterday's action was a victory for a coalition of liberal Democrats, conservative Replublicans and restoration groups including the American Institute of Architects and the National Trust for Historic Preservation, both of which lobbied extensively against the extension plan.