NEW YORK • They appeal to senior citizens and millennials, business travellers and backpackers. And they are particularly attractive to hotel developers, who can pack in more guest rooms than in a typical hotel.
They are known as microhotels, inspired by the Japanese capsule or pod hotels of 40 years ago that offered cheap, tiny accommodation to businessmen.
The new versions - which are most common in, but not exclusive to, big, expensive cities such as New York and Paris - are designed, as one hotel expert put it, down to their last square centimetre.
Their guest rooms are small - often half, or less, the size of a typical room in an urban hotel - with furniture that often can be folded up or stowed away, and bathrooms that usually have showers and toilets but no bathtubs.
Their rates are less than typical urban hotels'. Rates at Moxy hotels, a Marriott brand, start, for example, at US$159 (S$220) a night in the United States.
With decor inspired by Japanese capsule hotels and airlines' first-class cabins, microhotels are increasingly popping up worldwide.
Mr Henry Harteveldt, president of Atmosphere Research, a travel research company, said the process of squeezing more rooms into a hotel resembles what the airlines have been doing to increase the number of seats on an aircraft.
While microhotel room rates and basic economy airfares might be relatively low, he said, the number of potential customers makes them attractive to operators.
Another plus for developers, said Mr Mark Van Stekelenburg, managing director of CBRE Hotels Advisory, is that the design of microhotel guest rooms makes them cheaper to clean and maintain than larger, more traditional guest rooms.
And the microhotel concept appeals to companies such as Marriott and Hilton, which recently introduced the Motto brand, because it allows them "to get more dots on the map", said Mr Michael Bellisario, lodging analyst for investment bank Baird. "The more properties and brands they have in all cities", the greater potential for repeat business.
The idea of small hotel rooms arrived in the US in 1989.
The Microtel brand, introduced in Rochester, New York, served value-conscious guests by offering rooms half the size of traditional hotel rooms, with rates that were also half the cost.
But industry experts do not consider Microtel, now owned by Wyndham, a microhotel brand by current standards, since its guest room sizes tend to be significantly larger than those of most newer microhotels.
Generally, microhotels today have guest rooms that range in size from about 115 to 220 sq ft, depending on the number and size of beds. A typical room at an urban hotel in the US can range from 250 to 300 sq ft.
Other large hotel companies have rolled out their own brands.
Introduced in 2014, Marriott's Moxy has 44 hotels in Europe, Asia and North America today and has signed contracts for another 96.
Hilton's Motto, announced last autumn, has more than a dozen projects under development in Europe, the US and South America.
Hyatt acquired its own microhotel brand, Tommie, when it bought Two Roads Hospitality in October.
Among the earliest independent microhotel brands were Yotel and Pod, which opened their first hotels in 2007.
There are now many more independent microhotel brands, including Hoxton Hotels, based in London; citizenM, based in the Netherlands; and Arlo in New York.
Guests staying at microhotels often have access to loyalty programme benefits: Customers at Moxy, Motto and Tommie hotels can or will be able to access the benefits of the programmes of the brands' parents, while some independent brands offer their own programmes.
Another type of compact sleeping accommodation, ranging in size from 30 to 56 sq ft, is also now available post-security at some airports in the US, including Atlanta, Dallas and Philadelphia.
Minute Suites and Sleepbox, which operate these, charge guests by time increments that can range from 15 minutes to overnight. Many Minute Suites rooms have showers, but Sleepbox provides neither bathrooms nor showers; its guests must use the airport's facilities.
Mr Van Stekelenburg said he did not anticipate that the attractiveness of the microhotel concept would dim any time soon.
"We will see continued efforts by independent and large hotel companies. I believe they're here to stay."