IT is a business which is defying the conventional wisdom that the high street is in decline.

The cafe bar operator Loungers – started by three friends in Bristol 17 years ago – is to float on the stock market in a bid to fund expansion plans which will see it adding 25 sites a year.

Nautico in St Thomas Street, Weymouth, and Vivo in Brewery Square, Dorchester, are among the 122 individually-named Lounges, and the business also has 24 Cosy Clubs. Consultants have described it as the only all-day operator of scale to be growing in the hospitality sector.

Crispin Farbrother, senior lecturer in hospitality management at Bournemouth University, said the secret of Loungers’ success was in occupying a “third space”.

“It’s not work and it’s not home,” he said.

“It enables people, particularly in the modern office worker, to go out with a laptop and work in these comfortable spaces. It’s quite different from an old pub because the old pub tends to be very male and these places are far softer spaces and women feel very safe in them and will relax in them.”

The venues serve meals, coffee and alcohol. Mr Farbrother said this presented an alternative to cafes which offered coffee and mainly sugary foods, or pubs which increasingly laid out cutlery and expected people to order meals.

“There’s no pressure to spend in there. They’re quite happy for you to sit in with a laptop and only spend a few pounds, so the modern worker will keep going back. If you can get repeat customers, they’re much cheaper than keep trying to attract new customers,” he added.

Hospitality consultant Simon Scarborough, of Simon Scarborough Associates, said: “I use them myself because they do it right. I go to them above everybody else because it’s all about the way they treat people. They seem to know by my facial expressions or body language that I want to be left alone or want to talk. They just effortlessly treat me correctly.”

He said the businesses “do very simple food well”, with the same ingredients used for different dishes, cutting overheads and making the menu easier to prepare. “You can go in and drink and not eat, or eat and not drink,” he added.

Private equity firm Lion Capital owns a majority stake in the company, but it is not expected to have any directors on the board following the admission to the Alternative Investment Market.

Chief executive Nick Collins said the stock market debut would provide the capital to pursue its expansion plans.

There will be five Cosy Clubs and 20 Lounges each year under the expansion plans.

According to independent analysis for the group by planning consultants CACI, there is room for more than 400 Lounges and 100 Cosy Clubs in the UK.

“Loungers is the only growing all-day operator of scale within the UK hospitality sector,” said Mr Collins.

“Our relaxed, casual, home-from-home proposition which combines coffee shop, pub and restaurant across our two complementary brands, Lounge and Cosy Club, resonates with today’s consumer, attracting broad demographic appeal in a diverse range of trading locations.”

Admission to the market is expected to take place by the end of April.