When theater producer Stewart Lane told Bonnie Comley he wanted to find a penthouse apartment with a fireplace and outdoor space before they got married, she thought it would be impossible, and suspected he might be stalling the wedding. Luckily for the two of them, Mr. Lane found the New York real estate equivalent of the Holy Grail — a 4,000-square-foot duplex with more than 1,000 square feet of outdoor space, a fireplace, six bedrooms, and six-and-a-half baths.

The couple, now married for 11 years, lives in an Upper East Side building built in the late 1950s by big-time New York developer Al Dworman. The penthouse apartment they live in was the developer’s, the only one in the building built as a duplex. The place was in such good shape when they bought it 11 years ago that they haven’t needed to do much renovation. The most major change was the addition of a steam room in the upstairs bathroom. “I suggest to everyone that they try and buy the builder’s apartment,” Mr. Lane said.

Mr. Lane, who is in his mid-50s, and Ms. Comley, who’s in her mid-40s, share their apartment with four of their five children (the eldest, Eliana, is 23 and lives on her own). The two middle children — Harly, 17, and Leah, 10 — live in the “children’s wing” on the apartment’s first floor. On the walls outside of their bedrooms hang photos of both Mr. Lane and Ms. Comley’s family members at all ages — spanning old black-and-white portraits to more recent color photos. One photo captures Mr. Lane and Ms. Comley’s wedding ceremony, with Mayor Giuliani officiating. “I’m big on pictures,” Ms. Comley, whose office shelves are filled with photo albums, said.

Also on the bottom floor is the couple’s library, filled with theater memorabilia. It is where the couple displays trophies: namely, their Tony awards (he has four, she has one), a number of Drama Desk awards, and one of the newest pieces, an Actors Fund Medal of Honor, awarded to them last month.

A wooden box holds some of the couple’s most prized souvenirs, including an array of opening-night gifts, lapel pins, and keychains from plays they’ve produced. There’s a “Thoroughly Modern Millie” flask, a bolo tie from “The Will Rogers Follies,” a “La Cage aux Folles” watch, and a silver keychain shaped like a clapperboard from Liza Minnelli, who starred in Mr. Lane’s “Minnelli on Minnelli.”

Mr. Lane has produced more than 30 Broadway shows, Ms. Comley seven, and the two have collaborated on seven. Next up, in early fall, will be a revival of “Godspell.”

Three shows — “The 39 Steps,” “Sunday in the Park with George,” and “Legally Blonde” — are currently running on Broadway. “George” has been nominated for Best Revival of a Musical, and “Steps” for Best Play at Sunday’s Tony Awards.

Mr. Lane was first bitten by the theater bug at 11, when he and a friend, Ricky, ventured into the city from Great Neck to see Ricky’s father — Sid Caesar — perform on Broadway. “I remember going backstage and just loving the whole experience,” he said.

On the walls of the library hang pieces Mr. Lane says “only a theater buff like myself would appreciate,” including signed photos of Irving Berlin and P.T. Barnum, and a self-portrait doodle by Jerome Robbins.

Hanging above the couch is a painting by Max Ferguson, of Mr. Lane and Ms. Comley at the Palace Theater, which Mr. Lane owns.

Right outside the library hang caricatures of the two created by Al Hirschfeld. Because he’s penned some of his own plays, Mr. Lane is depicted as a playwright. Ms. Comley is shown in her former profession, as an actress.

Across from these hangs a very different piece — a painting of Paris by impressionist painter Camille Pissarro, which Mr. Lane bought about 10 years ago. Ms. Comley said her husband is the more well-versed of the two in art. “I’m more into functional and aesthetic,” she said. “My wife is the tchotchke queen,” he added with a smile.

Also on the bottom floor is Ms. Comley’s favorite room: the kitchen. Light floods the entire space, which faces south. The open, airy space has a large, oak table and chair set featuring carved lions that Mr. Lane bought in a small store in the Village in the 1970s. The family eats most meals at that table, rather than in a large dining room across the hall (with a table that seats 16 comfortably). They can also eat on an outdoor annex, where an herb garden grows. Ms. Comley says one of her favorite spots in the home is a shaded area on the downstairs terrace where she can sit under a wisteria plant.

The outdoor escapes are not limited to the first floor. A winding staircase (over which hangs a two-story crystal chandelier) leads to the apartment’s second floor, and onto the ultimate oasis: a large, bright terrace filled with trees, plants, and flowers of all colors. It has an unobstructed view of the Baroque-style Saint Jean Baptiste Catholic Church.

The couple’s 21-month-old twins, Frankie and Lenny, have made their mark on the space. A section of the terrace that formerly featured chaise lounges is now squared off for the boys: with a slide, trampoline, and sometimes even a wading pool.

Inside, a study features another Hirschfeld drawing; this one is of “La Cage aux Folles,” for which Mr. Lane won his first Tony for Best Musical. The area, which was always Mr. Lane’s favorite spot in the apartment, has changed drastically in the last two years. “I used to sit up here by the fireplace, smoke a cigar, and watch my big-screen TV. Now it’s a playroom,” he said with a laugh.

Also on the second floor is the twins’ bedroom, a bedroom for caregivers, and a kitchenette.

Ms. Comley said that when she found out she would be having twins, the two looked for other places, and considered moving into a townhouse. “We just couldn’t find anything that was as bright and airy,” she said.