Christopher Thomas, one of two Washington reporters for The Times of London, sat in the dust in his office on the fifth floor of the National Press Building. He had no choice. The dust, an unwelcome byproduct of the building's reconstruction, was everywhere.

"Look at this filth on here," Thomas said, swiping some of the reddish residue atop his desk. "It's disgusting. I've been in scruffy offices before. But even by newspaper office standards, this is grim."

Some NPB tenants say conditions are too grim to stay in the building. The Times is relocating to what Thomas calls "cheaper, more congenial, more modern quarters."

The dust that is driving out The Times is a symptom and symbol of the problems -- including massive cost overruns -- that have plagued the ambitious renovation project and reached a near crisis this month.

Once estimated to cost approximately $45 million, including loan interest and debt servicing, the total project is now expected to cost close to $69 million -- and that is after several cost-cutting changes in plans. Construction costs alone have soared from approximately $30 million to near $40 million.

To pay for the huge overruns, the National Press Building Corp. is seeking a refinancing agreement with the New York State Employees' Pension Fund, which is providing the long-term mortgage for the building, and it's negotiating new short-term construction loans from the National Bank of Washington and the Bank of America. While not completed, those arrangements appear to be on track, building corporation officials say.

And in an effort to tighten the reins on construction costs, the building corporation recently brought in Donohoe Construction Co. Inc. as development manager, replacing DRG Ventures.

"People who have been through this before don't panic as quickly as I would -- and did," said building corporation president William D. Hickman, a former McGraw-Hill reporter who wrote for Engineering News Record and other construction publications.

"The whole project was victimized by unreasonable expectations," said Hickman. "We had a kind of journalist's mentality and borrowed the least amount that we could have, expecting that everything would come up roses."

Costs could have been as much as $10 million higher, had not the corporation found ways to economize. Most of the changes will not be noticeable, according to Hickman. "We had some marble in places where only pigeons would see it."

But some retail space on the second floor and a 150-car valet parking garage in the basement will also be pared from the project if approval is obtained from D.C. planning and zoning regulators.

The National Press Building Corp., which owns the building and is overseeing the project, is 78 percent owned by the National Press Club. The balance is owned by 209 individual and corporate investors, most of whom are small shareholders.

Hickman said the corporation has given up no equity in the building to pay for the cost overruns, which the refinancing arrangements are supposed to cover. "But if that fails," he said, "I guess we'd consider taking on an equity partner."

Despite the dust and delays, press building officials contend they are better off keeping the building in operation during construction than if they had closed down.

"If we had emptied the building" for reconstruction work, "we would have had a much harder time getting everyone back," said Hickman. He said the NPB has about 200 tenants and is about 65 percent filled.

"That's good for us. If you're in the real estate development business, which we're in, keeping a tenant base is the main thing," Hickman said. By those standards, NPB Corp. is "well ahead" of other developers who have new buildings going up, but no tenants, he said.

"Look at all of these cranes," Hickman said. Looking through an NPB window facing 14th Street NW, he pointed toward nearby construction projects. "They're all putting up buildings. But they have no tenants in them, and its a glut market situation. We'd much rather have 65 percent than zero percent."

But, to quote Arthur Jones, Washington correspondent for the National Catholic Reporter, life under reconstruction "has been hell."

Jones has a tiny office on the 11th floor, next door to what he calls "downtown Lebanon." That's the pessimists' view. An optimist might look at it this way: You can walk out of Jones' office, open a door that once led to the offices of The Daily Oklahoman, and if it's a clear day, you really can see forever. There are no walls on much of that floor and several other floors have been stripped to their concrete skeleton.

The strategy for renovating the building while it is in use is like manipulating Rubik's cube. Tenants are shifted from one quadrant, then it is rebuilt and reopened so another can be redone. Unlike the quiet clicking of a cube, however, the job produces a chorus of jackhammers, hand-held pneumatic chisels, and other tools and "noise that just drives you out of your mind," said Jones.

"It's like living in a dentist's chair," he said.

NPB Corp. and press club officials have tried to alleviate the suffering of their tenants and colleagues by asking the construction workers to do their drilling and banging at night, but that doesn't help out-of-town and overseas journalists whose deadlines are several time zones away from Washington.

A huge chute is outside the London Times' office window facing F Street NW. Around 5 p.m., the chute explodes with the ca-chunks, booms and rumbles of tumbling bricks, bits of steel girder, broken mortar and other reconstruction rubble pushed from the building's top floors.

"It's quite noisy stuff," said Nick Ashford, the Times' chief Washington correspondent. "It's quite dramatic when it starts."

Horror stories about life in the NPB flow one after another like bulletins on a breaking news event. For example, everybody remembers the trash fire in the basement.

It happened Sept. 28, at about 3:15 p.m. Janet Battaile, deputy Washington bureau chief of the Dallas Morning News, smelled something strange. But she thought it was the insecticide a colleague had sprayed to turn back cockroaches fleeing the devastation of the upper floors. She mis-sniffed. The corridors were filling with smoke.

"There was no fire alarm," Battaile said in a statement confirmed by the building's management, which said the system had somehow been incapacitated during construction. Tenants shouted the alarm and banged on doors. Battaile said she used a stairwell to get out of the building. "The smoke was so thick, I could hardly see the person in front of me," she said.

She escaped safely. So did everyone else. But Battaile, echoing the sentiments of others, said the fire "galvanized people" already reeling from reconstruction woes. "I heard people saying: 'I'm moving out tomorrow. I can't tolerate this anymore,' " she said.

The wailing brought action. The fire alarm was fixed. Extra effort was made to control daytime construction noise and dust.

Other agonies: computers overheating and failing because water was cut off from air conditioning systems cooling the computer rooms; vital wire service lines "going down" (for several hours in one case involving Reuter's) because of electrical failures; ceiling tiles falling out (as they did on one occasion in the offices of the Financial Times of London) because of overhead drilling.

"Knowing how bad it's been, I'm surprised we haven't heard more squawks," said NPB Corp. president Hickman. He said the corporation has established "SWAT teams" composed of press club members to work with the builders in eliminating nuisances as quickly as possible. "We're not unmindful of what we're putting people through."

The faithful are enduring reconstruction miseries because the NPB "is a special place" designed to serve the needs of the national and international news media, Hickman said.

Benjamin Shore, correspondent for Copley News Service, agrees. Copley has signed a new five-year lease with NPB Corp., even though Copley's rent will double (from about $13.50 per square foot to $26) when it moves from its temporary NPB quarters into its reconstructed digs.

"One of the reasons we and other news organizations want to stay here is that the building is being designed to suit the needs of news operations," Shore said. "Little things," such as a master antenna for microwave communications, cable-TV hookups throughout the building (including C-Span, which provides gavel-to-gavel coverage of House and Senate sessions), and news conference rooms will make the NPB more amenable to the media, Shore said.

"I can't really say that this has been an intolerable experience, or that we're sorry we stayed," said Shore. But he said he believes the building management erred by not telling its tenants about all of the difficulties they would encounter if they chose to stay on during reconstruction.

"The press building corporation has a lot of public relations problems. Most of them come from not candidly and accurately describing what the problems would be. Every day, there is a little surprise, noise or something. It's an annoyance, but it's not intolerable," Shore said.

"The thing that people wonder about is whether they are going to have to suffer through these conditions for three years," said Vivian Vahlberg, president of the National Press Club since January. "They won't. A lot of the worst of the dust and noise is over, and its manageable."

The building is expected to be one-quarter renovated by spring with tenants moving into the new, improved space in April, said Hickman.

Construction is generally on schedule, Hickman claimed, with the project expected to be completed in May 1985. But tenants disagreed. Battaile said the new Morning News bureau on the 12th floor was first scheduled to be ready for occupancy this winter, then next November and now January 1984.

Vahlberg said that, contrary to rumors, there are no plans to close the press club's bar and restaurant. But the club has replaced its food service contractor, switching to Restaurant Associates from ARA Services. Vahlberg said Restaurant Associates is doing a better job of working under stress.

Rumors have been as much a part of the renovation project as the dirt, noise and debris. Among the big tenants reported to be leaving the building are McGraw Hill, Reuter's (bureau chief Bruce Russell says the agency is still "looking at options") and United Press International (also exploring options).

Knight-Ridder has moved out for the duration, taking up temporary digs at 1319 F St. But Hickman said Knight-Ridder already has signed a "long-term lease" to move back into NPB when reconstruction is completed.

"Ideally, it probably would have been a good thing to close the building down, renovate, and bring the people back in. But the building management opted, with the consent of the tenants, to do renovation with as many tenants as possible remaining in the building," said Jeanette M. Gavel, the building's manager.

Ideally, it might have been better to skip the project altogether, said Jack Thompson, who runs the newsstand in the lobby. Thompson, whose father bought the NPB newsstand in 1954, said he has lost 35 percent to 40 percent of his over-the-counter business since reconstruction began.

"I do a lot of business outside of the building. Without that, I wouldn't survive," said Thompson, estimating that "50 percent of the people, individual people, have been chased out" by the noise and dust. CAPTION: Picture 1, Exterior view of renovation on the National Press Building at 14th and F Streets, NW. Photo by Ray Lustig -- The Washington Post; Picture 2, Upper floor of the National Press Building, stripped to its skeleton for renovation. Once estimated at about $45 million, the total project is now expected to cost nearly $69 million -- after several cost-cutting changes in plans. Construction costs have zoomed from about $30 million to $40 million; Pictures 3 and 4, William D. Hickman, president of the Nationa Press Building Corp.: "The whole project was victimized by unreasonable expectations." An unfinished hallway. Photo by James K.W. Atherton -- The Washington Post; Photo by Ray Lustig -- The Washington Post