Christopher Mathieson is the managing partner of JC DeNiro & Associates, a boutique brokerage firm with offices in TriBeCa and Chelsea. The firm, which opened with funding from the Lower Manhattan Development Corporation after the September 11, 2001, terrorist attacks on the World Trade Center, is opening another office on the Upper West Side in several weeks. He spoke recently with The New York Sun’s Julie Satow.

Q: Your firm is closely associated with downtown. Why have you decided to open an office uptown?

A: There is so little product left downtown, and uptown offers our clients so many more opportunities. As an example of how limited inventory is downtown, I haven’t even put the pictures up on our Web site yet for a two-bedroom, two-bath apartment asking $1.299 million at the London Terrace at 400 West 24th St., and I only showed it for a single day, and already all three people who saw it have made bids.

I just got back from showing something at the Mercantile Building in Chelsea that is asking $2.249 million, and the building, which has 354 units, usually has at least 10 apartments on the market at one time, and now there are only four.

I love the Upper West Side. There is so much luxury product that is hard to find downtown, such as all the $10 and $15 million homes on Central Park West and in the Time Warner Center that are much rarer in Chelsea and TriBeCa.

Uptown is as close to being in the suburbs as you can be without leaving the city, and I think it is a natural progression that we would open an office there to satisfy our customers.

Many of the smaller real estate boutiques have consolidated with the larger players in the market. Have you considered joining forces with the bigger firms?

I wouldn’t sell. I compare JC DeNiro to an exclusive private school, where we emphasize training, a high level of service, and personal attention.

We have only a handful of agents, but even if we had 100 brokers, it would be the same thing. If I sold the firm, everything we did would be diluted.

If you could advise a young couple looking to buy real estate in the city, what would you suggest?

My advice would be to stop renting. Once you are in the market, you are in play, and anywhere you buy in the city, you can double your money.

Just stop renting, because if you are paying $4,000 a month in rent, it equates to $48,000 a year toward someone else’s mortgage, and $100,000 in opportunity costs.

Where you decide to buy all comes down to lifestyle, what part of the city you work in, where you like to go out.

I would suggest narrowing it down to a neighborhood and getting something conducive to your lifestyle. Get something now, then you can leverage that for a larger apartment three to five years down the road.

The government has set it up for home ownership in this country, offering couples that keep their apartment for two years tax-free capital gains, and allowing interest payments from mortgages to be written off against salaries.