A House Built Close to the Train, but Only Temporarily Among the items that have passed through or made a temporary home in Grand Central Terminal in the last 100 years: Three elephants on the way to a circus in Boston; an art school; a tennis court; a Redstone rocket; a Philippe Petit tightrope walk; a model train show. And now, a two-story house. Over the weekend, two teams of 50 construction workers each toiled for 48 hours to raise a 21-foot-high, 1,540-square-foot living space in Vanderbilt Hall, the vast marble-floored entryway near 42nd Street. The home includes a full-size kitchen, dining room, living room, master bedroom, bathroom, guest room, two rooftop decks and a linen closet. Its entryway is paved in faux brick; its doorway is guarded by thick white columns and a gathering of manicured bushes. Access in and out is easy, though, because each room lacks a wall. The house is a marketing promotion for Target and is outfitted with wares from its new home line. How much did it cost to launch the product line in one of the busiest and most famous transportation centers in the world? "I wish we could say," said Amy Joiner, a spokeswoman for Target, "but we can't." On Monday at 7 a.m., with commuters streaming in from Greenwich, Conn., and Westchester County, a few hired hands peeled back a set of black curtains to unveil the home. At least a dozen "brand ambassadors" - women wearing large white hair bows and red lipstick - began to gush like extras on Home and Garden television, inviting visitors to "feel, touch and see everything on display." Robert T. Russell, 67, an accountant wearing a paisley tie and a blue plastic button ("Minds are like parachutes," it read. "They only function when open.") stopped to ogle. "It's a very smart move on their part," he said, standing by the faux brick entry. Look at the traffic they're getting. Building a house in Grand Central Terminal, of course, came with a unique set of challenges, which fell to Kelli Frazier of Deutsch LA, an advertising agency hired by Target. As the executive producer of "experiential" marketing, Ms. Frazier thinks up flashy publicity stunts for companies and brings them to fruition. She oversaw the house project from the beginning. "This is the biggest thing we've built for anybody," she said. Our other clients are a little less adventurous. The house began to take shape in March in New Hampshire in a workshop owned by Trigger, a company Deutsch used to assist with the construction. When the structure outgrew the workshop, Trigger employees moved it to a warehouse in Long Island City. There, they built it completely - a test run - then disassembled it. On Friday at midnight, they loaded the parts on to three 48-foot trucks and one 26-foot truck and prepared for the voyage to Grand Central. Ms. Frazier said coordinating the project in New York City was kind of like bringing the circus to town - but a lot more complicated. There were the parking permits for the trucks, and the rules that the governed construction. The house had to be broken into 4-foot-by-8-foot panels to fit through the terminal's narrow doorways. The house consists of more than 200 panels, which fit together like puzzle pieces. The Police Department's canine unit sniffed every item, including the cosmetics being used for makeovers on Monday, to check for explosives. Every light fixture and pillow had to be sprayed with fire retardant. The house had to be outfitted with emergency exits. There were "rounds and rounds" of approvals from various government agencies, Ms. Frazier said. And there was the issue of the hall's gilded chandeliers, complicating Deutsch's dream of a towering two-story home. "Typically, you're just like, "Oh, we can remove the chandeliers,"" Ms. Frazier said. But these are forces of nature. You don't mess with these. The solution? Ms. Frazier and her team positioned the house between two light fixtures. The guest room is on the second story, and juts up between them. The house will stay in Vanderbilt Hall until Tuesday evening, when breakdown begins. The furnishings will be donated to a local charity. Does it seem like a lot of work for just two days? "It does," said Hermina Belin, 46, a lab technician heading home to Peekskill after visiting a friend in the city. "I thought it was very nice," she said. But a bit too manicured for me.