An artist’s impression of the 250-metre office tower on Chowringhee

Calcutta — and India — will get its tallest building at 250 metres when a commercial property comes up on Chowringhee, next to Tata Centre.

The tower, to rise to a height equivalent to 83 storeys, will be the city’s first run in the construction Olympics that is dominated by Burj Dubai at 636m.

“We will actually construct 54 floors, but at 250m, it will easily be the tallest commercial structure in the country, its height corresponding to an 83-storey tower,” says A.N. Shroff, the leader of the consortium Diamond Group that is developing the building.

To come up on the vacant land that was once the proposed site for a Grand Hyatt, the 54-storey structure will tower over the Chowringhee skyline, housing 10 levels of car parking at the base and a helipad on top.

The tallest building planned in the city before this was the Life Insurance Corporation’s 50-storey commercial structure on the Bypass.

Shroff had purchased around five bighas that belonged to the Maharaja of Darbhanga in 1993 from the high court, and the Diamond Group later bought another portion. The company is in the process of acquiring another contiguous chunk to enable access to the property from Middleton Street as well.

While Burj Dubai is the tallest structure in the world in all four of the criteria listed by the Council on Tall Buildings and Urban Habitat, the Imperial Towers in Mumbai, at 60 storeys, is the tallest India has till date.

“The Chowringhee building will have many firsts, like a 4.2m floor-to-ceiling height, a grand entrance lobby 42ft high, a sky garden on the 29th level, restaurants on the 50th and 51st floors and three levels of viewing galleries above that,” says Vinoo Chadha, principal architect for the project.

His city-based Design Cell has designed the tower, which tapers off at the top, and will have a programmed illumination system to project varied façade views at different times during the night, showing just a brilliant blue streak along the spine at 2am.

“All necessary structural precautions are being taken, including the seismic load factor,” said Chaddha.

Structural expert Joseph P. Colaco from Ottawa is doing the structural design along with local structural engineer Sanjeev Parekh. Construction, outsourced from a Singapore firm, is expected to take 24 to 30 months from the date of sanction.

With the land cost at Rs 432 crore, construction is estimated to cross Rs 200 crore. “We want this building to be the calling card of contemporary Calcutta, and will bring in services to match the grandeur of the structure, like the rooftop helipad,” said Shroff.

The tower will yield 35-36 floors of office space, with a food court and convention centre spanning three levels.