NINE hours of isolation or 30 minutes trapped by the office bore? The attentions of the boss or the distractions of daytime TV? The choice between slogging to the office and working from home can be pretty unappealing. For increasing numbers of people, the answer is “co-working”.

The concept of co-working is elastic but at its broadest means working alongside, and often collaborating with, people you wouldn't normally. Users book a space in a co-working office, plonk themselves down where they can and start beavering away. (Opening the laptop in a Starbucks is not quite the same thing: enough stick-in-the-muds go to coffee shops to drink coffee that it is not a proper working environment.)

The idea first surfaced a few years back, but according to Steve King of Emergent Research, a California-based outfit, it reached an inflection-point about 18 months ago. The absolute numbers are still small: Mr King reckons there are now around 760 office-based co-working facilities in America, up from 405 in 2010.

Their rise is fuelled by several things, including technologies such as cloud computing; more women and freelancers in the workforce, which means greater demand for flexible work arrangements; and economic pressure on firms' property costs. Nor is the trend confined to office workers. An organisation called BioCurious recently opened a community biology lab in California's Bay Area. Budding chefs share kitchens; communal workshops known as “maker spaces” are springing up too.

Some co-working spaces are dedicated facilities, others are set up within business incubators or company offices. Campbell McKellar, who runs a website called Loosecubes where people can find spaces to work, says that 65% of the 2,800 workplaces available are inside small, private companies with desks to spare. Creative and media businesses with a culture of bringing lots of people together to work on specific projects are heavily represented among both users and space providers.

New co-working chains are emerging, with names like The Hub and NextSpace. More established firms have also cottoned on to the trend. Regus, a big provider of managed office space, has a product called Businessworld that offers cardholders flexible access to its facilities. Mark Dixon, Regus's boss, likens it to having airport business lounges in city centres, and says that products like this already account for 20% of the firm's revenue, up from almost nothing before the financial crisis.

Purists are sniffy about the likes of Regus. Generation Y-ers do not aspire to work in airport lounges: Loosecubes offers people a choice of working atmospheres that include the “hacker vibe” (black T-shirts and not much in the way of light, apparently). The benefits of collaboration are stressed. One strand of the co-working movement is the “jelly”, an informal event, often held at specific times of the week, where people gather to work together. Co-working evangelists also emphasise the role of each facility's “host”, a person who organises social events for users, introduces people to each other and spots opportunities for collaboration.

Still, there should be room for many different styles of co-working, particularly if it takes off among larger companies. Some big firms are trying to soup up innovation by getting people to co-work internally: the striking new Sydney offices of Macquarie, a bank, have no personal desks and emphasise collaborative working. Others have already started shedding their own properties: Yell, a directories business, is now using Regus memberships to give its salespeople in Britain access to office space when they want it. Drew Jones, co-author of a book on co-working, thinks that there is scope to turn empty retail space in the suburbs of big cities into large co-working facilities. Compared with city-centre offices, these would take less time for people to commute to and cost less for firms to buy or rent space in.

None of this signals the end of the conventional office. Corporate cultures move slowly, for one thing. Managers worry about how to deal with issues such as confidentiality. Some job functions will always benefit from being in one location. But co-working multiplies the options that people have when they ask themselves: “Where shall I work today?” For that reason alone, it will keep spreading.