With quirky but comfortable rooms, the Malmaison chain has converted all sorts of buildings into hotels, from a seed store in Belfast to a prison in Oxford, writes Emma Cullinan

There's a bar in every room of the new Malmaison hotel in Oxford, England, but they don't all supply alcohol and salty snacks to crunch on aimlessly when watching late-night television.

The latest hotel in the 16-strong, and growing, Malmaison group used to be a prison and a requirement from the conservation monitors was for the bars on the doors of each cell - now comfortable rooms - to remain intact.

Working within such constraints doesn't faze the Malmaison group, in fact they seem to thrive on it. All of their hotels so far have been in conversions of old buildings. In Belfast they've transformed two former seed warehouses close to the city centre; in Glasgow they've reformed a former Greek Orthodox church; in Newcastle they've revamped a derelict warehouse; in Edinburgh a former seaman's mission (and more recently a brothel) is enjoying a new wave; while currently on track is the conversion of a Great Western Hotel in Reading and the Malmaison's first new-build hotel, in Liverpool.

"Design-wise, the cornerstone of everything we do is in the properties we buy. By opting for quirky buildings we display our maverick, bohemian approach," says Robert Cook, Malmaison's chief executive officer, who oversees the design of the hotels with an in-house team.

Converting old buildings means that their hotels have to be designed around existing structural features, such as columns and stairwells, as well as contorting rooms into awkward spaces.

In Oxford, for instance, where bedrooms overlook an exercise yard, one room has a bath on a balcony in a lounge, graced with a large movie screen. "We work around the building," says Cook, pointing out that watching a film from the bath can be fun. "The big boys don't get it," he says referring to some of his larger rivals who look for "standard-sized soulless spaces".

Each hotel has a different interior but they all share a chic, comfortable feel. The designs also work with the building. In Oxford the harshness of the structure's steel and stone has been countered with opulent fabrics. In Belfast the communal spaces are pupil-wideningly dark, with a sort of French boudoir look.

Malmaison is, after all, named after the château Josephine bought for Napoleon to rest in - with herself - following his strenuous battles. The 60 Belfast hotel bedrooms are sharper and brighter than the communal areas, with an Eastern feel brought about by cream, white, brown and black.

There are also references to the local environment, in the form of photographs of murals from the walls of Belfast. I ask the obvious, and am assured there's an equal number of images from both sides of the sectarian divide, distributed throughout the building. Such explosive art seems to be a part of Malmaison's challenging ethos. "We do look for the extraordinary," says Cook.

The two penthouse suites are named after the Harland and Wolff shipyard cranes - Samson and Goliath - with one of the rooms incorporating a billiard table. There are also nine-foot beds and double baths, while in all of the bedrooms the sinks are Belfast-style. Cast-iron columns, stanchions and roof beams are all visible in the Belfast building and the original staircase descends into reception.

Right from this area it is evident that Malmaison hotels aren't conventional. The reception desks are low-key and set to one side of the room with no written sign to say that this is where you check in. It quickly becomes obvious what its function is and you relax in armchairs as your room arrangements are processed. A manager tells me that it is policy not to ask whether you'd like an alarm call - it's all part of the relaxation and homely feel.

"We believe that every night away from home is a begrudged night, so we want to make the experience better than home," says Cook.

Apart from being trusted with a hairdrier that isn't clamped to the wall, and the provision of a kettle, customers are expected to be cool enough to cope with the packets of condoms in the bathroom, iPod docking stations in every room and hefty sized, good quality toiletries, that you are implored to take home with you.

"The bedlinen and duvets have just been upgraded - to duck down - because we are selling a good night's sleep," says Cook, who grew up in a hotel in Aberdeen.

Using quirky buildings and having a maverick bent, with a healthy dose of comfort and style, has brought the hotel chain a fan base (of 155,000 'live profiles'), with customers asking what's coming next. And there is a lot, with a planned expansion from 16 hotels to 25 by 2008.

There'll be some new buildings but also the special older ones, following Cook's belief that, "heritage is always better than heresy".