Last year was the Year of the Lifestyle Hotel, with Marriott, Hilton and InterContinental among the many players introducing new brands or making acquisitions in this hot market segment.

A rendering of the Bisha Hotel in Toronto which is slated to open next year as part of Loews ’s OE Collection of lifestyle hotels--- INK Entertainment

Last year was the Year of the Lifestyle Hotel, with Marriott, Hilton and InterContinental among the many players introducing new brands or making acquisitions in this hot market segment.

After less than a month, 2015 looks on pace to surpass it.

Three major hotel operators – Hyatt, Loews and Langham – are preparing to launch new boutique or lifestyle brands, joining a crowded field of hospitality companies offering properties that emphasize high-design and a social bar scene.

The new brands are aimed primarily at younger travelers, or at least those who emulate the behavior of youth. They are widely viewed as critical to capturing the coveted Millennial generation — often defined as those born between 1980 and 2000 — and coming at a time when new hotel construction is cranking up after a long hiatus.

Hyatt has the most ambitious plan of the new entrants. The Chicago-based company this summer plans to open 20 lifestyle hotels in places like New York, Miami, San Francisco and Paris, according to people familiar with the company’s strategy.

Loews Hotels is launching its own lifestyle product, known as the OE Collection. The hotel operator will partner with boutique and independent hotels to manage those properties and incorporate these properties into the Loews distribution network.

While the typical Loews hotel has 200 or more rooms, the OE Collection will feature smaller properties of 150 or fewer rooms and feature more adventurous design than the flagship brand.

Loews’s first agreement is with Bisha Hotel, a Toronto hotel and luxury condo created by Canadian entrepreneur Charles Khabouth to open next year.

Langham Hotels, a Hong Kong-based hospitality company known for its gilded luxury properties, is also developing a lifestyle brand out of its New York office. But first it is launching a new full-service product, called Cordis, to compete against high-end brands like Westin and Fairmont.

“We will offer the same service as our Langham brand but without the opulence,” says chief executive Robert Warman.

The company is opening its first Cordis in May, converting one of its existing hotels in Hong Kong. The new brand will start primarily in China and other parts of Asia but Mr. Warman said he is also exploring sites in the U.S.

Even some lifestyle hotel veterans feel the need to jump back in. Brad Korzen, the former chief executive at the high-end boutique operator Viceroy Hotel Group, said last week he is launching a new brand called Proper Hotels with its first hotel in San Francisco opening later this year.