Behind the classic facade of US-born designer Sasha Bikoff’s prewar Greenwich Village duplex lies a tale of 18th-century France and glam disco-era bravado. Or, to put it another way, Marie Antoinette meets Studio 54 and 1980s Palm Beach.

“I’m inspired by the eccentricity of different eras,” says Bikoff. “So when I discovered the original 80s powder room in this place, it sealed the deal. It was just so far out that I had to live here.”

‘It’s the perfect place to display all the antiques and crazy things I’ve collected’: Sasha Bikoff at home. Photograph: Genevieve Garruppo/The Observer

With its original white grid-tiled walls and lipstick-red fittings, the powder room remains untouched by Bikoff, who began renting the two-floor garden apartment off lower Fifth Avenue, shared with her dogs Puff Daddy and Dipsy, two years ago. She did, however, embark on cosmetic changes. “I couldn’t do anything structurally, so I’ve decorated it in my own style. It’s the perfect place to display all the antiques and crazy things I’ve collected,” she says.

The result is a happily haphazard nostalgia. She breathes lavish new life into vintage treasures. You enter the apartment into a cosy, open-plan living/dining area painted in Farrow & Ball’s subtly pink Calamine. Built-in cupboards are lined with George Venson’s Voutsa butterfly wallpaper and a sliding glass door leads out to a small garden. In the compact kitchen, existing cabinetry is revived in Farrow & Ball’s Breakfast Room Green, a nod to Bikoff’s love of food and cooking, while a framed vintage Gucci silk scarf hangs on the wall, depicting a leopard and a black panther circling one another, perhaps for dinner.

“I approach my interior work like a painting,” she explains. “It’s a ripple effect. Once you start with certain colours, you find ways to bring in others, and then it’s about building up the layers and adding prints and textures. I don’t like to decorate all at once. It’s all about the process.”

Animal magic: the kitchen, in Farrow & Ball’s Breakfast Room Green and with an electric pink sofa. Photograph: Genevieve Garruppo/The Observer

A white staircase snakes up to the two bedrooms (one of which is now a dressing room), where high ceilings allow for a good flow of natural light, and two bathrooms, which have yet to receive the Bikoff treatment. The entire apartment feels like a vintage emporium. Bikoff inherited her collector gene from her late grandmother. “She taught me how to appreciate vintage design and stylistically beautiful interiors and couture,” she says. Inspiration was also drawn from frequent visits to flea markets in Paris, where Bikoff studied art history at the American University. She started her New York-based business in 2014, with clients now including Versace, with whom she collaborated as part of Milan Design Week last year.

A glance in any direction of her home transports you to the 1950s or 70s one minute, or the 1980s or 90s the next. “I enjoy the hunt in finding antiques. I don’t think about where anything will go in a room, I just make it work and create a new story,” she says. “I think it’s quite romantic to imagine how the pieces in my home have all had multiple lives and owners in different settings.” Her hunting grounds include auctions and antiques markets in LA, Miami and Palm Springs.

In the living area, a mid-century chaise longue covered in gold and silk sits next to a walnut Vladimir Kagan chequerboard-pattern table and 1970s Tommaso Barbi “Rhubarb” floor lamp. They look like leftovers from a decadent cocktail party. In contrast, pink Campana Brothers plastic and steel Zig Zag chairs give a space-age feel around a 1970s French Lucite and mirrored dining table. “They’re not the most comfortable things to sit on, but I’m style over comfort every time!” laughs Bikoff.

Sentimental objects, including family photos and vintage Murano and Fenton glassware heirlooms, line the shelves of a floor-to-ceiling 1960s Pierre Cardin wall unit. She is also fond of chairs, and reupholstering them – no two are the same. “I love finding different shapes and then complementing them with the right fabric.” A croissant-like sofa in electric pink is teamed with leopard-print chairs and a pair of Milo Baughman swivel seats, which she calls her “marshmallow chairs”, are in crushed velvet.

Shoo! The dressing room, complete with goose. Photograph: Genevieve Garruppo/The Observer

Every corner reflects her passion for colour (pink, mainly), her artistic flair and fondness for whimsy, from kitsch ceramic dogs and a lone retro carousel pony to a light-up Hollywood sign. Everything is equally seductive with unabashed femininity, including a print of a 1960s Pirelli calendar girl on the bedroom wall. In the same room, a pink palette has a calming effect, with long white curtains framing the windows. A gilded, Venetian-style dressing table sparkles with amethyst crystal knobs added by Bikoff, along with a stool she re-covered in a vintage Hermès scarf. A 1920s Chinese deco rug covers the wood floor and Victorian ceramic lamps decorate two Italian animal-print side tables, with floating glass tops. She also made the crushed-velvet headboard over an ample-sized bed with a faux-fur throw. A chrome bench at the end is covered in a ruffled velvet fabric by Marc Jacobs.

Bikoff created the agate geode slab table which stands next to a French Louis XV–style fauteuil with needlepoint upholstery, by sourcing the stone from Brazil. “The table has such a celestial feeling and I just love the energy it brings.”

Her dressing room, painted in Farrow & Ball’s Lulworth blue, has rows of pretty heels, Hermès Birkin bags and Louis Vuitton vanity cases, and there’s a slinky 1970s Vladimir Kagan chaise longue reupholstered in silver velvet.

Bikoff’s home is constantly evolving. “It’s the ultimate expression of what I do,” she says. “My home characterises who I am, and that’s why it’s such a wacky, fun and interesting place.”

• This article was amended on 29 January 2020 to correctly attribute the images to the photographer Genevieve Garrupo.