— Designer Tony Ingrao had four weeks. His job was to create an arresting look for the room with 16-foot ceilings and a view of St. Patrick’s Cathedral he’d been assigned at the Kips Bay Decorator Show House opening May 1.

Fortunately, Ingrao, whose clients include Howard Stern and Kim Cattrall, happened to have available a massive Ron Arad stainless steel fire screen that hadn’t quite worked in an Aspen ski lodge. It took 15 men to gently maneuver the $1.3 million sculpture into the 1884 Villard Mansion, at 457 Madison Ave. Meanwhile, the room’s walls had been coated with platinum-colored glaze dusted with mica powder. A 14-foot creamy chenille “On the Rocks” floating sofa by Francesco Binfarè was installed to provide seating for up to 25 people, who could admire the 14 paintings and sculptures arranged throughout the space.

“Decorating today is about making rooms genuinely interesting,” Ingrao said. “If you walk into a room and it’s not exciting, you get bored.”

No worries here. When 22 of the nation’s top design firms are selected to adorn a historic Gilded Age mansion, you’ll get 22 rooms full of splendor and stories. A gem by architecture firm McKim, Mead & White and adjacent to the glitzy Palace Hotel, the posh location was used as a backdrop in the filming of the TV show “Gossip Girl.”

This show house is good for inspiration and bad for anyone with house envy. It’s hard not to covet Alexa Hampton’s jewel-toned Moroccan sitting room, which is both exotic and European. “It all started with a tile I saw late one night trolling the Internet,” Hampton said. Soon she was picking out velvets and wool paisleys and tufted chairs. Matthew Quinn’s stylish gray kitchen has nine-foot-tall glass-front silvery gray cabinets whose quatrefoil detail was taken from the windows at St. Patrick’s.

Juan Montoya assembled an imposing main salon, anchored with a serpentine sofa of mohair velvet, leather and faux fur astrakhan. Two cuddly Vladi­mir Kagan 1970s swivel chairs in wool shearling beg to be taken for a spin. The sparkling 1830 crystal chandelier weighs over 300 pounds.

“Grand, old school decorating is back,” tweeted Michael Boodro, Elle Decor’s editor in chief, after touring the three decorated floors.

For designers, being selected to do a room at Kips Bay is about as prestigious as winning an Oscar. Many drop everything to curate a space that will inspire a wealth of Instagramable moments and, hopefully, a few venture capitalists as new clients. The anointed rooms will be dissected at countless cocktail parties. Photos will be published in shelter magazines, buzzed about in blogs and pinned to Pinterest boards in the months to come, making this show house a branding bonanza.

Proceeds, usually $1 million to $1.5 million annually from about 20,000 visitors, benefit the Kips Bay Boys & Girls Club. The 2014 show house is lavish, provocative and beautiful: definitely worth a Bolt bus or NetJet journey.

Washington designer Darryl Carter was among the chosen this year, and his first Kips Bay room is elegant and rustic with his favored neutral palette. It has the look of a Parisian flat with its Regency-style chaise, found artifacts and four-poster metal-and-suede daybed of his own design.

“Doing Kips Bay is a hallmark moment for a designer,” Carter says. “There is so much talent here. For me, it equals a trip to Europe in terms of inspiration.”

Cool factor? On the second-floor landing, Brooklyn graffiti artist Victor Fung came on site with his spray-paint cans and created an original artwork, “The Scream,” on one wall. Fung’s installation gets even more of an urban edge because there is a glowing “Exit” sign in the middle of it.

Everyone knows accessories make the room. If you go, you will immediately know why architect William T. Georgis put a Japanese woven lacquer tray full of rusty railroad spikes in his room titled “Study in Red.” (Hint: It has a religious theme.)

It’s always fun to sniff out creative details, from the black patent-leather wainscoting in Young Huh’s Hollyhock Lounge to the 1960s Pucci scarf once worn by Brigitte Bardot in Cannes and now framed in Christopher Peacock’s “Lady Penelope’s Dressing Room.”

Speaking of scent, the fragrance of expensive perfumed candles and sumptuous spring flower bouquets wafts from room to room. The smell of money indeed.

Kips Bay Decorator Show House

Open daily through May 29. Admission is $35. For more information, go to www.kipsbaydecoratorshowhouse.org or call 212-755-5733.