With separate entries, a guest parlor, a wine-tasting area and a formal dining room, the layout had “the privacy of the owners and guests in mind,” said Ms. Genovese, a Wall Street refugee who figured that innkeeping would be more compatible with being a stay-at-home parent. Each of the three guest suites — in a two-story wing of what the Genoveses decided to call the Vintage Bed Breakfast Inn — was named for a wine and decorated accordingly. Each has a private bath with whirlpool tub.

But with their two children now in high school, the Genoveses would like to move on to other pursuits. Suzi Chase, an associate broker with Daniel Gale Sotheby’s International Realty, recently listed the bed-and-breakfast both residentially, as a single-family home, and commercially, for $995,000.

“Bed-and-breakfasts are fabulous to convert to residences,” Ms. Chase said. “Because you have your own entrance, you could use it as a mother-daughter or as a nanny suite.”

The Long Island Convention and Visitors Bureau lists 50 bed-and-breakfasts, 32 of them on the North Fork. Hal Zwick, the director of commercial real estate at Devlin McNiff Real Estate in East Hampton, estimated that in the last decade, the number of these places declined 25 percent.

That is at least in part because residential real estate on the East End is “more valuable than as a business,” he said. Most houses suitable for bed-and-breakfasts are “larger homes with multiple bathrooms, and that’s what people are looking for these days, especially for vacation homes.”

Requirements for maintaining a bed-and-breakfast include having a fire inspection once a year, a fire escape ladder in each upstairs bedroom, and a fire extinguisher on each level. Innkeepers must also serve breakfast and afternoon refreshments.

Although Ms. Genovese called her bed-and-breakfast “definitely profitable,” she said it was difficult to put a price on, “because I am the bed-and-breakfast.”

Naturally, she added, buyers not inclined to bake muffins each afternoon or serve three- to four-course breakfasts to guests each morning “are looking at it as a summer home for extended family or a full-time home with a large family.”

Some sellers of such properties hope that doesn’t happen. Peter and Cheryl Castiglione have listed their Home Port BedBreakfast on an acre in Peconic for $1.195 million as a turnkey inn, including the furniture, silverware, bedding and guest robes. An 1867 Victorian, it has four guest suites and was initially a single-family home. But for the last 30 years it has been operating as a bed-and-breakfast, the last seven of them as the Castigliones’ “empty nest project.” The couple have their own living and dining rooms and two bedrooms.

Although it could sell as a private six-bedroom home, Ms. Castiglione said the house, with its wraparound front porch and great entertaining spaces, “is a home with a heart and it really needs to be shared.” It doesn’t have the “big master bedroom with the walk-in closets” that buyers seek, she said, or the “big soaking tub in each bathroom that people want.”

For Pamela Paynter, who is also selling a bed-and-breakfast, the issue of whether hers remains one is less significant. For the last seven years Ms. Paynter, a sales associate with Brown Harris Stevens, has been innkeeper at Fordham House in Greenport. She recently listed the place, a 1901 Queen Anne with original stained glass, a wraparound porch and four guest rooms, for $975,000. The house is zoned residential with a permit to operate as a bed-and-breakfast; it has intermittently been used as a private residence.

“It really can be either,” Ms. Paynter said. “It is very accommodating and it is homey,” but formal in that “it is not cluttered up with family pictures” and “a little impersonal for most people’s homes.”

The commercial-to-residential shift is also occurring in the Hamptons — despite a dearth of overnight lodgings. But the inns in question are a good bit larger.

A Great Neck developer, Distinctive Management, is four years into a project to convert the 114-room Panoramic View, an inn that it bought for $50 million, into 60 luxury oceanfront condop residences — co-ops with a condominium plan. Prices range from $1.875 million, for a one-bedroom, to $4.1 million for a four-bedroom unit.

“We saw a need in the market,” said Adam Manson, a principal, “for something that was hassle-free,” with Ritz Carlton-style concierge amenities including porter and maid service, grocery delivery and dry-cleaning service and “24/7 maintenance.”

So far 38 resort rooms in the Hilltop, one of the buildings on the 10-acre property, have been renovated as 10 luxury duplex residences with hot tubs and barbecues on each deck. Another building, the Salt Sea, is now home to 10 residences. Half of the 20 new units are sold, said Ed Bruehl, the sales and marketing director. The rest of the complex still operates as a resort, with a pool, beach umbrellas and towel service. Rooms run from $195 a night, in the off-season, to $1,000 a night in August.

In Southampton brokers are suggesting that the historic Village Latch Inn, listed in January for $25 million, could be reinvented as condominiums.

“If someone can’t live on Fifth Avenue, they want to live in Southampton,” said Faith Hope Consolo, the chairwoman of the Prudential Douglas Elliman’s Retail Group, who co-listed the property and is extolling its “unprecedented development opportunities.”

She suggested that the inn’s main house, which is on the National Register of Historic Places, remain as a small bed-and-breakfast. A developer could replace the other three cottages on the five-and-a-half-acre grounds with condos. “It is a lovely hotel,” she said. “It has been that way forever, but it is time to move on.”