The site is a local landmark, so it is hard to believe that eight years ago the building was destined for demolition — and much easier to understand the recent excitement over the sale of its upper floors as residential units.

Demolition was discussed when the building "was bought by a developer and neither he nor the local authorities were interested in saving it," said Ken Bolan, an antiques expert who is the current owner. "But I could see its potential. It has immense style and character and sits well in its location. I hated the idea it would be turned into another soulless block."

Mr. Bolan’s connection to the site goes back 40 years, to a period when he looked for vintage cars for wealthy clients. The delivery address was the garage housed in the Talisman building. "In 1970 it was a gas station, with pumps on the forecourt," he said. "I didn’t realize how beautiful the architecture was until years later, then I wanted to own it."

When the original developer dropped the project in 2004, Mr. Bolan bought the 18,000-square-foot, or 1,700-square-meter, four-story property, and it became a showroom for his vintage furniture and design business. In addition to a general refurbishment of the ground floor and exteriors, he commissioned copies of the railings and glass lanterns that once lined the front entrance, so the building now looks much as it did originally.

Mr. Bolan recently decided to make the most of the demand for London real estate by selling the two middle floors for conversion to residential use. He has permission to turn the first and second levels into architect-designed apartments, each filling a 5,600-square-foot floor.

"The idea is to turn both floors into contemporary living spaces that respect the original fabric of the building," said Edoardo Mapelli Mozzi, managing director of the real estate search agency Banda, which introduced buyers for both properties to Mr. Bolan and will manage the renovations.

"There simply isn’t anything like this for sale in such a prime location," Mr. Mapelli Mozzi said. "An increase in international investors over the past 10 years has pushed prices in the superprime areas of London, like Mayfair and Belgravia, to unprecedented levels." He also noted that there was a limited amount of top-end properties for sale at any one time, so the market was always tight.

"Anyone buying on the open market has little chance of securing the best properties; around 80 percent of our business is via private or off-market sales," he said.

As soon as it became known that the building’s middle floors were for sale, Mr. Bolan said he was swamped with offers. "I could have sold the properties several times over but I wanted the buyers to be people who would respect the building and help create something exceptional," he said.

The buyers prefer to remain anonymous and will not disclose the prices. But, Mr. Mapelli Mozzi said, they "can see the potential for turning these large industrial areas into unique homes, and they’re prepared to take the risk of redeveloping commercial space."

Past commercial tenants, who have included the fashion designers Amanda Wakeley and John Galliano, made substantial changes in the interiors. But the building still has the original metal-framed windows and rough-painted brick walls and beams.

The upper floor also retains the steel girders and ironwork struts supporting the vaulted ceiling and skylights, which will be incorporated into the final design.

The plans are still in the early stages but the Paris-based architect Joseph Dirand and the London firm Barrett Lloyd Davis have been hired. The work will involve removing stud walls to enlarge the internal spaces and uncover some windows, to add light to the interiors.

Mr. Mapelli Mozzi estimates that, when completed, each of the apartments will be worth around £8 million, or $12.6 million.

Potential buyers still have an opportunity, as the 2,000-square-foot penthouse has just recently been put on the market. As with the first two apartments, success will depend on whether Mr. Bolan believes the buyer will be the right one to own a spot in his building.