By JOYCE COHEN
THERE are things New York apartments typically lack -- a yard, a parking place, a washer-dryer. But there is one thing they do possess: floor plans, most often derived from buildings' original marketing materials.
Floor plans are important when an apartment goes on the market and a listing goes on the Web, real estate agents say, because buyers in New York depend so heavily on them.
''If I don't have it on the Internet right away, people want me to fax over a floor plan,'' said Lauren Cangiano, an agent at Halstead Property Company in Manhattan. She added that ''there are things that will make you not visit an apartment if it doesn't show on the floor plan.''
''People want split bedrooms; they don't want bedrooms next to each other,'' Ms. Cangiano said. ''Or they want a kitchen with a window so they can sneak a cigarette.''
A floor plan shows the entire unit, not just part of it. In other words, floor plans reveal what photographs often do not: the proportions of rooms, the number of rooms and the traffic flows among them. A buyer can instantly see, for instance, if the kitchen is conveniently situated near the dining room, whether bedrooms open directly onto the living room or whether a trip to the bathroom will involve a walk through a bedroom.
''When you look at a floor plan, it is the apartment standing there naked,'' said Gerald Makowski, director of marketing at Halstead Property.
Floor plans are starting to move into three dimensions, a real help for those who have trouble visualizing physical space. Some developers show elevation plans, where you can pick a floor from the side view of a building and then highlight a particular unit. More customization is likely as technology improves.
Outside New York, however, floor plans are rarely used as marketing tools by brokers who are reselling houses, although they are more likely to be used by builders of housing developments, who include floor plans as one of the many tools on their Web sites.
The Toll Brothers Web site, for example, includes an elaborate ''design your own home'' feature allowing people, within limits, to experiment with the floor plan. ''They get to design something with the builder and make it their own, and not settle for a resale situation where someone else has made those decisions,'' said Kira McCarron, chief marketing officer at Toll Brothers.
Those who are downsizing scrutinize the floor plan most thoroughly, said Kara Opanowicz, a vice president of architecture for K. Hovnanian Homes. ''We have a lot of move-down buyers -- empty-nesters taking their furniture with them,'' who want to be sure everything will fit, she said. ''They are concerned with the exactness of what they are getting.''
Brent Gleeson, the president of NewCondosOnline.com, which markets new condominiums worldwide, estimated that 90 percent of the properties that he was selling featured a floor plan online. In fact, the most requested items from prospective buyers using the site are prices and floor plans.
These plans help buyers determine ''how much space they want and need,'' Mr. Gleeson said -- something they are not able to do with an on-site visit. ''Builders do preconstruction and presale advertising, so they are marketing properties that have not yet been built.''
Some individual agents are beginning to create floor plans to distinguish themselves from the competition. Christine Pardo, an agent at Kroll Realty in Fort Lauderdale, Fla., often creates her own floor plans for clients, similar to those she created when she was a kitchen designer. It is timeconsuming: She spends an hour measuring and another hour working with a computer program.
People are always impressed by the result, she said. Currently, with so much inventory in Florida, ''it would be easy to show a buyer between 6 and 25 homes a weekend,'' she said. ''After 25 homes, which are you going to remember? The ones you are holding paperwork on.''
Sellers who want to create their own floor plans or experiment with designs can try user-friendly programs like those from smartdraw.com and plan3d.com.
There are endless debates about what floor plans should feature, and there is no standardization, so users should be aware of what the plans show and what they do not.
Many include a key plan, showing the unit's location on the floor of a building. But what about the swing of the doors? A thick line to indicate a load-bearing wall? The depth of a fireplace mantel? Some include interesting extras, like a label for a skylight.
But plenty of basic structural information can be missing: the height of the windows, the width of hallways, the placement of electrical outlets, the apartment's overall condition. Some lack an arrow pointing north.
Older plans usually show crosshatching in kitchen and bathrooms, to distinguish wet and dry areas. Now, the convention is to use crosshatching only in bathrooms, said Doug Barton, who creates floor plans for several New York real estate brokerage firms.
''I don't do it in kitchens,'' he said, ''because you have other things going on there. People want to know how many bathrooms there are, but usually there is one kitchen.''
In addition, dimensions are often printed on floor plans, but there is no guarantee that they are accurate. ''You must always challenge the dimensions,'' Mr. Barton said. ''I have seen two particular situations that were wrong. There was a squarish bedroom labeled 10 feet by 15 feet and a rectangular bedroom labeled 14 feet by 14 feet. So use your brain.''
Stephen Joseph, vice president for store design of Bergdorf Goodman, loved the floor plan of a West End Avenue one-bedroom coop, but was ambivalent when he finally saw the apartment. Almost every window faced a brick wall -- a deal breaker that hadn't appeared on the floor plan. Only the living room had a view of the street, and not a nice one.
''I went back time after time,'' he said. ''I tortured myself.''
Mr. Joseph ended up withdrawing his offer and buying a duplex with a floor plan that revealed lots of open space. This one had a lovely view of Broadway. What counts for him, Mr. Joseph said, are the three L's: layout, light and location.
''I have seen so many apartments that didn't have any views, that were all interior,'' he said. Had this information been on the floor plan, ''I never would have gone to see them.''
To help people read floor plans, Brooklyn Bridge Realty in Cobble Hill, Brooklyn, has started using three-dimensional ones prepared by the Gotham Photo Company. Clients love it, and ''it is so much easier to read than a bare floor plan,'' especially when it comes to staircases, said Jean Austin, the owner.
That third dimension is likely to be increasingly important. ''Real estate lends itself really well to 3-D,'' said Vince Collura, director of business development for Gotham Photo.
He predicts that people will be able to zoom into the floor plan, so that ''instead of a bird's-eye view, you're at a standing level,'' he said, and to customize the plan by changing the color of the walls and floors.
Technology has made people increasingly design-conscious, helping them realize that layout may be as important as size, said Leonard Steinberg, a vice president at Prudential Douglas Elliman in New York.
''The big shift happened when people realized how much space a regular TV used rather than a plasma TV,'' he said. ''The clunky old TV took up four square feet. Hello! That is $4,000 in New York!''
WhichWay Is Up? Here's Some Help
IF you have trouble understanding or making use of floor plans, here are some suggestions: Compare a room with one that is familiar. ''My old bedroom was 12 by 18,'' said Alison Rogers, an agent at DG Neary Realty. ''I can't tell how big a room is, but I can tell if it is bigger or smaller than my bedroom.''
Play designer: Enlarge the floor plan and make cutouts of your furniture to scale, so you can rearrange them on the plan and see how everything fits.
Carry a tape measure and verify measurements. ''Sometimes those measurements are really wrong,'' said Leonard Steinberg of Prudential Douglas Elliman.
Look up. If you are distracted by the furniture and cannot see the edges of a room, looking at the ceiling will give you the footprint, with some exceptions, like a kitchen island or peninsula, said Bradford Trebach of Trebach Realty in the Bronx. JOYCE COHEN
