The scheme - for Rothschild Bank - will sit next to Christopher Wren's Church of St Stephen Walbrook.
Both Rem and his client argue that the proposals will 're-instate' the 18th-century link between the church and St Swithins Lane.
In a joint statement, the pair claimed: 'This has the potential to make the churchyard, with its historical gravestones and precious oasis of green, part of the daily City experience.'
'Instead of competing as accidental neighbours, the Church and the New Court will form a twinned urban ensemble, an affinity reinforced by the proportional similarity of their towers.'
The New Court project will be the first new-build by the international star in London, where he is a resident.
It will be made up of a central core of 10 flexible office floors, linked to three annexes, with meeting rooms, an auditorium, vertical circulation and reception areas.
A Sky Pavilion will sit on top of the central cube, which will house client meeting rooms and a 'multi-functional panorama room', with views across the City, including St Paul's Cathedral.