Daun Paris is a woman of certainties.

Growing up in Ridgewood, N.J., she was certain she had athletic abilities good enough to compete well against boys in biking and karate. At Sarah Lawrence College, where she majored in economics and performing arts, she was certain that after graduation she would land on her feet in the professional world.

When she arrived in New York and brazenly walked into a realtor’s office on Madison Avenue, she was certain she would land a job. Of course, she did.

When she branched out on her own and founded Eastern Consolidated in 1983 with partner Peter Hauspurg, Ms. Paris was certain her company would become America’s biggest single-office commercial real estate business – which, of course, was exactly what happened.

And when she looked at the volume of business coming her way in commercial real estate deals, she was certain her revenues would keep growing to the point where, in 2004, sales would be nearly a billion dollars. She was right: The ledger showed $850 million. Now Ms. Paris is certain the revenues for 2005 will approach $2 billion.

On the basis of Eastern Consolidated’s sales to date, her certainty most likely will be borne out.

Why not? She’s rarely been wrong.

So is there a secret to all this?

“It’s really a matter of self-confidence,” Ms. Paris said. “It’s surrounding oneself with very smart people. It’s ensuring that your company always emphasizes integrity and discipline. It’s developing lasting relationships. Business success is all of these things.”

It’s also having a lawyer who enjoys a reputation for negotiating skillfully through the complexities of real estate law. It’s also having a husband who helps out with the business.

In fact, it helps even more when the lawyer and husband come in one package. That package is Mr. Hauspurg, with whom Ms. Paris launched Eastern Consolidated.

A husband-and-wife team working in the same office? Surely, the reporter asked, wouldn’t that be, well, a wee bit delicate?

“No,” Ms. Paris said, with – what else? – certainty. “We do entirely different things. I run the management and administration. I no longer go out to make the deals. He focuses on the deals. There are many days when we don’t even see each other in the office.”

That may be because the office is commodious. It’s staffed by more than 50 brokers and other employees. Ms. Paris said she hires only the best – which is why, on a per capita basis, Eastern Consolidated may have more MBAs and holders of law degrees than any comparable enterprise.

Many of those staffers are also multilingual. That’s a huge help when it comes to dealing with foreign clients. Which is why, Ms. Paris said, her office echoes with mellifluous languages such as Hebrew, Farsi, Mandarin, and Spanish.

Indeed, relationships with key sources abroad have enabled Eastern Consolidated to “quickly arrange equity placements” in various commercial deals, Ms. Paris said.

“Eastern Consolidated has done more development deals than anyone else,” she said, patiently explaining to the jargon-challenged reporter that a “development deal” was one involving raising a structure from the ground up.

So what’s next?

“More of the same, of course, but widening Eastern Consolidated’s operations beyond the tri-state area to Florida and other states,” Ms. Paris said. In fact, the company already has done deals in Chicago.

Her record of success has had a few dips, naturally. Back in the early 1990s when the real estate market was fraying, she decided to hang in there. “When other companies were going under, we stayed afloat – in fact, we even tripled our office space,” Ms. Paris said. After September 11, 2001, when the real estate market was also buffeted by ill winds, Ms. Paris made a similar decision to persist in deal-making. Behind each decision was her certainty that things would work out. Was that prescience or unbounded self-confidence? “Perhaps both,” Ms. Paris said. She said she was certain her 19-year-old son, Philip, who attends Duke University, will go into real estate, just as she did in the footsteps of her father, Irin. (Ms. Paris also has a 17-year-old daughter, Alexandra.) What explains her certainty that Philip will be the third generation in her family to embrace real estate? Ms. Paris smiled sweetly. “He told me,” she said.