A luxury central London hotel popular with celebrities could be closed for years following a large fire, according to an architecture firm that previously worked on the building.

Flames ripped through Chiltern Firehouse in Chiltern Street, Marylebone, on 14 February – caused by burning wood falling from a pizza oven.

Architect Harriet Pillman said restoring the Victorian four-storey building was likely to be “complex for lots of reasons”.

Meanwhile, it is feared a prolonged closure of the five-star hotel and restaurant could have a knock-on effect on other local businesses.

The fire, which began about 1500 GMT, damaged parts of the ground floor, half of the second floor and destroyed the third floor and roof.

Formerly Manchester Square Fire Station, the 1889 building was converted into a 26-suite hotel and 200-seat restaurant in 2013 and became known as a celebrity haunt.

A representative of the hotel told the BBC he did not know the full extent of the damage nor how long it would take to restore it.

Ms Pillman – whose firm Donald Insall Associates helped convert the building into a hotel and also worked on the restoration of Windsor Castle after the 1992 fire – said the initial stages of the work would take at least a year and it could be three years until its ready to reopen.

“Projects like this are complex for lots of reasons, the main one being that the initial stages are very different to a normal architectural project.”

She said the building first needed to be stabilised, the fire-damaged material needed to be removed and the structure had to be dried out.

“It’s only then that architectural proposals can be developed,” Ms Pillman said.

Neighbouring retailers, mostly independents, believe the Chiltern Firehouse is important for the local business community.

Brendan Murdock, who runs the health and beauty store anatomē told the BBC it was “really quite shocking” to see the hotel in flames.

He said the closure of Chiltern Firehouse had already had a “significant” impact on footfall into the street, and it had missed out on the “currency of traffic coming through” for the hotel.

“There’s generally an energy around the hotel bringing people into Chiltern Street.”

Mr Murdock said he hoped restaurant could open as an outdoor eaterie during the summer months.

“It’s super important for us for it to be open… and without it we’d lose a lot of footfall coming into the street.

“So it’s a big concern. How long will it take to re-establish their business?”

Josh Fehnert, editor of Monocle Magazine, which also operates a cafe and two shops on the street, said the fire had been a “gut punch for the neighbourhood”.

Describing the Chiltern Firehouse as “a big character” on the street, he said it was also an important part of the community of local businesses.

Mr Fenhert acknowledged that it could now remain closed for a considerable period of time.

“There is a plan to re-open the building and we’re optimistic,” he said.

“We need a little bit of time to take stock and also make sure the renovations are done properly and this building is respected as it’s brought back to life.”