Previous spread: At this 1883 landmark building in the Flatiron district, interior restoration involved improving the 11-foot-high windows. Photography: Martin Crook.

Left, from top: The practice took over 2,500 square feet of raw space on the second floor. The designer stands in the space before construction began. Photography: Martin Crook. Right: In the studio, Tanksley's eight associates work at custom partners desks clad in plastic laminate. Rico Espinet designed the pendant fixtures. Photography: Adrian Wilson.

Top: An Irish 19th-century mahogany armoire stands in the studio, between the entry and the pantry. Center, from left: An oil on canvas by George Barecca hangs in Tanksley's office. In the conference area, French 1930's chairs in oak and leather surround a French 1950's table with a top veneered in rosewood. Bottom: Leather-covered brass benches flank a secretary by T.H. Robsjohn-Gibbings in the slate-floored entry. The plaster pendant fixture is from the 1960's. Photography: Adrian Wilson.

Opposite: An Italian 1950's table topped in terrazzo and chairs upholstered in goatskin furnish a corner in Tanksley's office. A 1960's carved-wood sunburst sits on the windowsill. Photography: Adrian Wilson.

Left: At the garment-district studio, plywood slats define Laura Bohn's own office, while rough-cut maple partitions the workstations outside. Right: The designer sits on a banquette in the conference room. Photography: Eric Laignel.

Opposite: In the men's restroom, a laser-cut plastic curtain separates the sink and toilet. Photography: Eric Laignel.

Top, from left: PVC poles support the cedar slats. A partition separates reception, with its ash banquette, from the conference room, furnished with John Hutton chairs and George Nelson pendant fixtures. Bottom, from left: Nylon carpet tile flows around the custom cedar reception desk, reclaimed from Bohn's first office. A custom marble-topped table serves as her desk. Photography: Eric Laignel.

Left: In the office of the project manager at the SoHo space, Thomas Jayne sits in front of a window shade painted by Chuck Hettinger with an image of the 18th-century gilt-wood bracket installed nearby. Right: In reception, gym-supply steel storage baskets serve as the trim-and-sample library. Photography: Frank Oudeman.

Top: Custom 8-foot-tall fiberboard bookcases flank the entry to the president's own office. Bottom: Reception's commode, circa 1780, is from the German city of Dresden. Behind the commode and a Jean Prouvé chair hangs a collage by Robert Warner. Photography: Frank Oudeman.

Opposite top, from left: An early 20th-century pawnshop's gilded balls hang above the conference area's Eero Saarinen table and French 1940's bridge chairs. The chairs in the president's office are custom. Opposite bottom: Theater curtains delineate areas and help control acoustics. Photography: Frank Oudeman.

Left: In reception at the Midtown office, the firm's magazine collection is stored in custom blackened-steel shelving. Right: The conference room's tempered-glass enclosure captures the reflection of the architect. Photography: Eric Laignel.

Top, from left: Panels of compressed recycled paper surround David Mann's plastic-laminate desktop. The 22-person staff members occupy workstations clad in plastic laminate. Bottom, from left: Cotton canvas totes hold swatches and samples for client meetings. Existing concrete flooring remains in place. Photography: Eric Laignel.

Opposite: Komplot Design's rubberized chairs surround a custom conference table with an acrylic top and a base of plywood and blackened steel. Photography: Eric Laignel.

PROJECT TEAM: JIM CORBETT. FILE CABINETS (STUDIO): PANOLAM INDUSTRIES INTERNATIONAL. DESK SURFACING: ABET. PENDANT FIXTURES: RICO THROUGH ROBERT ABBEY. ARMOIRE: THROUGH BALASSES HOUSE ANTIQUES. PAINT (STUDIO, ENTRY): BENJAMIN MOORE & CO. TASK CHAIR (OFFICE): HERMAN MILLER. PAINT: FARROW & BALL. CHAIRS (CONFERENCE AREA): THROUGH LINDA & HOWARD STEIN. PENDANT FIXTURE: THROUGH ABC CARPET & HOME. BENCHES (ENTRY): PASCAL BOYER GALLERY. SECRETARY: THROUGH RAGO ARTS AND AUCTION CENTER. FLOOR TILE: STONE SOURCE. MIRROR: GALAXY GLASS AND STONE. CHAIR UPHOLSTERY (OFFICE): CLARENCE HOUSE. CUSTOM SCREEN: CHELSEA FRAMES. CARPET: BENTLEY PRINCE STREET THROUGH BEAUVAIS CARPETS. GENERAL CONTRACTOR: ORIENTAL CONSTRUCTION.

PROJECT TEAM: JENNIFER VAUGHN. DESKTOPS (OFFICE AREA), MIRROR (BATHROOM), TABLES (CONFERENCE ROOM): IKEA. CHAIR FABRIC (OFFICE AREA), CUSHION FABRIC (RECEPTION): INNOVATIONS. BANQUETTE UPHOLSTERY (CONFERENCE ROOM): THROUGH B&J FABRICS. SINK, SINK FITTINGS, TOILET (BATHROOM): KOHLER CO. FLOOR, WALL TILE: WORLD OF TILE. LAMP (RECEPTION): ARTEMIDE. PILLOW FABRIC (RECEPTION), CHAIRS (CONFERENCE ROOM): DONGHIA. PENDANT FIXTURES (CONFERENCE ROOM): MODERNICA THROUGH DESIGN WITHIN REACH. CARPET TILE: SHAW INDUSTRIES. UPHOLSTERING: K. FLAM ASSOCIATES. MILLWORK: T. STATHEM PLATZ. CONSTRUCTION MANAGER: BFI CONSTRUCTION CORP. GENERAL CONTRACTOR: NJACC.

PROJECT TEAM: CHRISTA KELLY; NANCY ROMEU. BRACKET (PROJECT MANAGER'S OFFICE): THROUGH YEW TREE HOUSE ANTIQUES. BASKETS (PROJECT MANAGER'S OFFICE, RECEPTION): SALSBURY INDUSTRIES. TABLE (CONFERENCE AREA): KNOLL. CHAIRS (CONFERENCE AREA), TABLE (PRESIDENT'S OFFICE): THROUGH BERND GOECKLER ANTIQUES. COMMODE (RECEPTION): THROUGH KARL KEMP ANTIQUES. PAWNSHOP BALLS (CONFERENCE AREA): THROUGH LOST CITY ARTS. CUSTOM CLUB CHAIRS (PRESIDENT'S OFFICE): CUSTOM INTERIORS SHOP; PINDLER & PINDLER (FABRIC). DESKS (STUDIO): THROUGH BERGEN OFFICE FURNITURE. CHAIRS: HERMAN MILLER. CURTAIN FABRIC: ROSE BRAND. CUSTOM WINDOW SHADES: MANHATTAN SHADE & GLASS. TRACK LIGHTING: LIGHTOLIER. MILLWORK: LIV DESIGN. LIGHTING CONSULTANT: MEEKER CAMERON LIGHTING DESIGN GROUP. .PROJECT ARCHITECT: SCOT CAMPBELL.

PROJECT TEAM: WILLIAM CLUKIES; ROBIN E. CORSINO; JASON WELKER. FILE CABINETS (OFFICE): RAY HESS BUSINESS INTERIORS. DESK SURFACING: FORMICA CORPORATION. PANELS: HOMASOTE COMPANY. CHAIRS (CONFERENCE ROOM): TROY. CUSTOM TABLETOP: MUNIZ PLASTICS. PAINT: BENJAMIN MOORE & CO. GLASSWORK: GRAY GLASS CO. MILLWORK: SORAYA. LIGHTING CONSULTANT: FILAMENT 33. MEP: JACK GREEN ASSOCIATES. GENERAL CONTRACTOR: ACCURATE GENERAL CONSTRUCTION.

A century-plus after Western Union opened a branch in what is now the Flatiron district, the Henry J. Hardenbergh–designed gem has a tenant worthy of its pedigree. "It's an old building living in contemporary times, and that marriage really befits my design," says Alan Tanskley, who collaborated with designer Anthony Pellino to renovate the 2,500-square-foot space.

During the course of the six-month job, a 75-foot-long wall of windows was restored—the sills, hinges, and wainscoting. Pipes and ductwork, on the other hand, were left exposed, skewing toward the industrial. Furnishings are a combination of the refined and the quirky. Tanksley's dexterity comes through clearly in the reception area, where a mirrored door frame gives a nod to Dorothy Draper. His eight employees work at simple partners desks clad in wood-grain plastic laminate. In his own corner office, behind a glass wall, he himself sits at a vintage table in black glass and bronze. And a chandelier painstakingly made from paper clips, essentially a giant metal basket, hangs in stylistic defiance of the Flatiron Building right outside—definitely the money shot.

Think of the stuffy showroom of an old-fashioned Manhattan furrier: black walls, vertical mirrors, the requisite vault. Now try to imagine Interior Design Hall of Fame member Laura Bohn conjuring incredible lightness from 3,800 square feet of garment-district space. Walls are sanded down and painted white, their luminosity intensified by afternoon sunlight. Rough-cut maple forms workstation partitions, while a slatted plywood wall fronts her office. "It's privacy and no privacy," she says with a sigh.

Desktops and many of the furnishings are mass-produced, and, yes, Bohn paid retail. The cedar reception desk was brought over from her first office, its pale gray wash softening the horizontal wood grain. Overall, the look is eminently professional yet unmistakably cozy—from the throw pillows on the banquette to the marbleized pattern of the carpet. "People come in and say it looks like a living room," Bohn says. "I can't help but do it."

Transience and New York are synonymous. When Thomas Jayne's firm outgrew its 650-square-foot office, and permanent new premises fell through, he sublet 2,000 square feet in a 1903 SoHo landmark for a 24-month pit stop. "It's like decorating for a party," he says. It's also like a stage set. Fiberboard bookcases, manufactured in a scenery shop, are set next to two massive columns. Pale blue theatrical curtains temper acoustics while amping up the glamour.

The reception area is typical of Jayne's way of fusing the classic and the current. On one side of the room, a high cabinet holds neat ranks of steel gym-supply baskets: the trim-and-sample library. The baskets' pierced details echo the rows of dots dominating a large collage on an opposite wall, behind a German 18th-century commode with ornate gilded-bronze drawer pulls. In the studio, 1950's steel desks, painted the green of drafting erasers, are paired with Aeron chairs. For Jayne, this sophisticated historical dance is decidedly delicate: "Anyone can put a Barcelona chair with a Chinese cabinet. It's like putting ketchup on french fries."

"A little austere," David Mann concedes, pausing by his Tulip table and surveying his 2,500-square-foot headquarters. "It shouts architecture office. And that's what I like. It's visually comfortable for me."

In converting two storerooms in Midtown, he says, he channeled Ludwig Mies van der Rohe for the "overall clean forms" and a combination of Donald Judd and Richard Serra for the abundance of plywood and blackened steel. The feel is frank, almost unfinished, with a concrete floor so distressed, Mann points out, that there's "no worry about spilling." Interior walls are confined to the black tempered glass around the conference room, where the table is topped a 4-by-8-foot slab of clear acrylic that looks indestructible.