Commercial property investor Posei Group wants to take one of its Sydney CBD buildings higher, filing plans for a seven-storey tower topper.

Posei’s proposal for the Citymark Building incorporates the old building, which it developed in the late 1980s, to create a 13-storey mixed-use building at 683-689 George Street, Haymarket.

Posei’s plans designed by Wardle would add terracotta firming to the existing building to create retail on the ground floor and add educational, community and medical space above.