The 625m 2timber structure, which will be 'clipped' on to the existing four-storey block in Fonthill Road, will be clad in zinc and polycarbonate panels and will provide four new business units.
Practice founder Martin King has been working on the scheme for nearly a year hopes the project will act as a catalyst for the re of the development of the surrounding area.
He said: 'The proposal involves adding a new structure over a random urban fabric which had been haphazardly added to and altered with no proper planning controls over the years.'
Described in the council report as a 'striking modern design', King said he is delighted the scheme managed to sail through planning. He said: 'Islington planners was extremely supportive of the proposals.
'Their report says: 'The proposal is striking in its shape and has been complimented by the design officer as appropriate to both the physical context and the use'.'
The scheme is expected to start on site next spring.