Birmingham's historic city centre fire service headquarters will be saved from demolition after it was granted Grade II listing.
Conservation experts said the move, which protects key features such as its clock tower, panelled committee room and fire engine gateway, could make it more difficult for West Midlands Fire Service to sell.
The fire service announced in 2005 it planned to sell the HQ, at Lancaster Circus, and relocate. The fire authority is attempting to sell for #3 million and move out of the city centre.
Staff will continue to work out of the 1930s building until 2008 when they will move to a new centre in Wolverhampton.
The Grade II listing, conferred by the Government after a campaign by heritage enthusiasts, describes in detail features to be kept intact.
Fire service bosses applied for the building to be made immune from listing, so the option of demolition would be available for developers.
Head of Conservation for Birmingham City Council, Chris Hargreaves, said the new listing would prove "certainly a constraint" for the developers.
"Although large parts of the complex have been altered over the years, and are of no historical interest, most of the rooms containing original features of the station must now be permanently retained," he said.
"There are details of the stonework and then internally it describes some of the rooms which have original features and terrazzo floors. There is a bronze statue of a fireman and elaborate oak panelling in the committee room. The interior of much of the rooms is largely original."
He said the conversion of the fire station would now pose more of a challenge for developers.
"Frequently there's disappointment when owners discover that their building has been listed. It may well be that because of these constraints the value of the building or the site or what you can do with the building is reduced.
"It would quite possibly put off developers. It's certainly quite a challenge."
In anticipation of selling the station off, fire bosses had applied for a certificate of immunity. It was already grade A or locally listed, in recognition of its heritage value, but that offered no protection against demolition.
"They must have thought it had the potential to be listed because they put in for a certificate of immunity, so it would not be listed for five years," said Mr Hargreaves. "It is a two-edged sword because it brings the building to the attention of the conservation authorities."
Aston University is interested in acquiring the station.
"The university is interested in the fire station if it was to become available. Its Grade II listing is a factor which will be taken into account," said a spokeswoman.
A fire service spokesman said it would be on sale in the New Year.
"West Midlands Fire Service has been working with Birmingham City Council to ensure a new use can be found for the existing headquarters building that reflects its landmark status and appearance while moving it forward into the future," he said.
"Throughout this time, it has been assumed that the building would be granted Grade II listed status, so the announcement has not impacted on that work.
"There has already been interest from some developers and new inquiries come in on a regular basis. The existing headquarters building will be advertised for sale in the New Year as planned."