While it’s possible to spruce up a garage for a few thousand dollars, major renovations can exceed $50,000, and a luxe garage, therefore, tends to be the province of the very rich.  “It’s such a perfect example of conspicuous consumption and keeping up with the Joneses,” said Elizabeth Currid-Halkett, a professor of public policy at the University of Southern California and the author of a coming book, “The Sum of Small Things: A Theory of the Aspirational Class.” “But there’s also a virtue of organization and cleanliness, so it links to the Protestant work ethic. Being organized shows that you are an upstanding citizen.”  Paul Greskovich, the owner of Garage Craft Interiors, has focused on the Interstate 287 and 78 corridors in New Jersey because, he said, “that’s where all the Wall Street money is.”  He started his garage remodeling business a decade ago, hitting upon a niche that was novel. He soon had 18 competitors, though that number has dropped since the fiscal crisis of 2008.  “The people who spend serious money on their garages are the ones who have already done everything else to the house, and they’ve got nice cars,” he said. “They suddenly realize that possibly the biggest room in the house is a debris field.”  Real estate brokers say a finished garage can add value and make an impression on home buyers. As more and more garages receive face-lifts, those buyers have come to expect a certain level of polish.  “I don’t think you have to take it to the nines, where you have heated floors,” said Libbe Pavony, a real estate agent with Houlihan Lawrence in Briarcliff Manor, N.Y. “But the garage is a reflection on how you maintain your home in general. Some people take their old kitchen cabinets and attach them to the walls.”  Ms. Pavony said heat was increasingly popular. “It’s a nice feature,” she said. “It’s great for hobbyists. If someone does woodworking, the garage isn’t just seasonal, and it can eliminate drafts in your house.”  Some homeowners are making renovations even more ambitious by expanding their garages. As family cars have morphed from station wagons to oversize sport-utility vehicles, many garages cannot fit two cars, let alone the other accouterments of suburban living, like beach chairs and bicycles, snow blowers and sleds. The emergence of shopping clubs like Costco and BJ’s Wholesale Club has put still more pressure on garages, with bulk items jockeying for space.  Lauren Hammer, a property manager in New York City, hired a contractor, Peter Glass, to figure out ways to get more space from her tight garage in Briarcliff Manor. He is adding three feet of depth while also removing the center column, which involved installing a 4,000-pound girder across the ceiling for support.  “My husband and I both drive S.U.V.s, and if you did food shopping, you couldn’t open the trunk and get the groceries out,” she said. “And without the center column, it will be so much easier to open your car door without worrying about nicking it.”  Mrs. Hammer did not stop there. A marathon runner, she decided to add a “woman cave” along one side of the garage, a fitness room where she can work out and cool down after runs.  “The idea is that I have my own space to stretch and not bring my sweaty things into our house,” she said.  Mr. Glass’s company, Meadowbrook Builders, is currently working on two other home renovations, garages included, within a short walk of the Hammers.  In one project, a couple who recently bought a split-level house wanted a central vacuuming system and a floor sink in the garage so that they could clean out their cars and wash their shoes before entering the house. In the other, a 50-year-old financial adviser doubled the size of his garage and installed two-zone heating for an adjoining work space. He also ordered a hydraulic lift so that he could hoist up his prized Porsche and squeeze another car in below. (The lift alone cost $40,000.)  With the ease of keypads to open and close garage doors, homeowners increasingly enter and exit their houses through the garage, Mr. Glass said. “Kids don’t carry keys anymore,” he said. “They have the code for the keypad, and if your garage door opens, you know it because you get an alert on your phone. The front door has really become just for guests.”  Mr. Glass believes that the constant exposure to the garage has helped propel it to the top of homeowners’ remodeling lists, especially among the affluent, and pushed their investments ever higher.  “The budgets are ridiculous,” he said. “I don’t get it.”  What seems to thrill some homeowners most about their renovated garage is the notion that everything has its place, whether a lacrosse stick, a flashlight or a spare tire. Mr. Teetelli, for instance, was more eager to show off his new storage units than his new Tesla. Maple-veneer cabinets concealed photography equipment, luggage, motorcycle helmets, cleaning products, batteries, a slow cooker, a pressure cooker and more than a dozen jars of Williams-Sonoma braising sauces, for which he admits a weakness.  Along another wall, a storage system consisting of floor-to-ceiling slats fitted with hooks held bicycles, patio chairs, ladders, snow shovels and assorted storage baskets. Nothing touched the floor.  “It’s so cool,” said Mr. Teetelli, 58, who also keeps two Harley-Davidson motorcycles in his garage.  Some homeowners skip the big-ticket items like epoxy floors and heating and go straight for the organization. Sort It Out, a firm in Scarsdale, N.Y., helps people organize their houses. The owners, Mauri Zemachson and Jamie Seslowe, usually show potential clients the garage of Ms. Zemachson, a mother of three.  Tall metal shelves are neatly lined with gardening supplies; Halloween decorations; balloons and bubbles; housewares like light bulbs, picture hooks and paper towels; and assorted sports equipment, including helmets for football, hockey and bicycling. A shoe tree holds 18 pairs of athletic shoes. Everything is labeled.  “Most of our clients are mothers who need order,” Ms. Zemachson said. She spoke from experience.  A version of this article appears in print on December 27, 2016, on Page A17 of the New York edition with the headline: Spending Tens of Thousands on Home Renovations … in the Garage. Order Reprints| Today's Paper|Subscribe
With homeowners having renovated traditional targets like kitchens and bathrooms, they are turning their attention to that most neglected of spaces.