Thomas Heatherwick explains his thinking behind the design of the soon-to-open Coal Drops Yard shopping centre, in this video filmed in King's Cross, London.

Heatherwick Studio is combining two 19th century buildings that were once used for storing coal into a canal-side shopping destination, which is due to open next month.

This video shows Heatherwick walking from his studio, which has been based in King's Cross for 17 years, to the new development, as he explains how the building's design came about.

"As a local person I was thinking what's missing, how do you do something that is really particular to here?" Heatherwick says in the video.

Heatherwick Studio's design for the Coal Drops Yard merges the two existing buildings by curving the two gabled roofs towards each other.

"Our breakthrough, in a way, was realising that we grow those [roofs], grow them together, because the roofs needed replacing," says Heatherwick. "And in replacing the roofs we could fuse those roofs together, as if it heals into a heart."

In the film Lisa Finlay, group leader at Heatherwick Studio, further explains the thinking behind the connection between the two 19th century buildings.

She says that the elements structures was integrated into the historic buildings without adding any additional load to the them.

"We tried all sorts of ideas of just adding something new, and the way we were adding it where they were quite separate just didn't work," she says.

"It was only when we started to merge the language of the old with the new, and that's when we started to have multiple ideas of things emerging from the existing forms."

Coal Drops Yard is the latest phase of the redevelopment of the area around King's Cross station in central London.

The shopping centre stands between the Central Saint Martins school campus and Wilkinson Eyre's recently completed Gas Holders. The former offices for the coal yards have recently been converted into a headquarters and studio for Tom Dixon, which also contains a restaurant.