Even when it was first proposed more than 60 years ago, the top of Vancouver’s robust main post office on West Georgia St. was considered prime real estate for an office tower.

Why that tower, an 11-storey proposal, was never built when construction of the city’s postal sorting facility began in 1953, or later in the late 1960s when an artist’s concept emerged complete with the new Canadian flag, is lost to history.

Now, the new owners of the recently-vacated building are considering a major redevelopment that may finally put an office tower on top of the redesigned structure, and even a hotel or condominiums, as well as convert the rest to a combination of retail and institutional space.

At the same time, the city and the owners, the B.C. Investment Management Corporation, are working to preserve as much of the heritage elements of the building, including the nearly five-metre high exterior bas-relief granite carving by Paul Huba called The Postman. The building, designed by prolific Vancouver architects McCarter, Nairne & Partners, is considered one of the finest examples of the International Style of architecture in Canada and at the time was reportedly the largest steel-welded building in the world.

Brian Jackson, the city’s planning director, said the city has received a development inquiry from Bentall Kennedy — the agent representing BCIMC, a government pension fund — that contemplates reusing the post office building, while adding additional office and residential space above.

The concept is in its earliest stage, and the developers haven’t begun negotiations with the city over various bonuses for retaining heritage or providing rental units.

But the project is of such significance that Jackson’s staff have given council a heads up. The report goes to council Tuesday along with another that alerts council to plans by Public Works Canada to redevelop the Sinclair Centre downtown.

Jackson said plans for the Georgia Street post office could change the dynamics of the area, which is close to BC Place, Rogers Arena and the proposed site of a new Vancouver Art Gallery.

“They are proposing a significant amount of density on top of the building and using the building in a very unique way for non-residential purposes, for retail and other uses,” Jackson said, in addition to wanting to add a residential component.

The old postal sorting office occupies an entire city block between Georgia, Dunsmuir, Homer and Hamilton streets and for decades was a dominant federal building. The backbone of Canada’s postal system in the west, it was built to handle the daily movement of tonnes of mail and could support heavy trucks rumbling inside. It includes seven floors underground, five above, in addition to a small three-storey office block above one area.

Inside, the building has high-ceilinged open-span spaces of 100,000 sq. ft or more, Jackson said.

“The building is quite extraordinary inside. It is built like a tank,” he said. “What they are proposing to do is put floors in between the big floors, in some cases for parking and in other cases for additional retail and non-residential uses, such as educational facilities, galleries and any number of things.”

The federal government sold the building in 2013 for about $130 million after also paying out land claims levelled by the area’s four First Nations. In 2014 it moved its postal sorting facilities into a new 700,000 sq. ft facility at Vancouver International Airport. At one point a developer considered buying it as the site for a new VAG, but the gallery declined, in favour of the city-owned Larwill Park two blocks away.

Tony Astles, Bentall Kennedy’s executive vice-president for Western Canada, said the inquiry “is very, very early in the process” and that no firm designs have yet been considered.

“Our goal is a sustainable mixed-use development that ultimately leverages the great transit and amenities in the area,” he said. “We have to work with the city, the planning department, the heritage department and the real estate department to see what we can achieve.”

Jackson said the inquiry from Bentall Kennedy and BCIMC proposes to build office, hotel and a mix of “for-profit affordable rental” and condominium housing above the existing building.

At street level, the red granite slabs that clad the ground floor will be removed and the space opened up for retail, Jackson said. The granite and other heritage elements would be reused within the building.

Jackson, whose team has already had a tour of the old building, said it was clear that the proponents are trying to be respectful of the building’s significance in Vancouver’s history.

“This applicant, right from the get-go, has taken a very sensitive approach to the redevelopment of this project. We appreciate that, and so yes, we think it is one of those that can accommodate a significant amount of density and that we can achieve a number of important city objectives.”

Jackson said the planning and design before a rezoning hearing could take up to 18 months. Astles said he doesn’t expect construction would start for at least two years.

jefflee@vancouversun.com

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