Developer Ecove, which still owns 30 apartments in Sydney's Opal Tower, has expressed sympathy for Icon, builder of the troubled residential building, but says the liability buck stops with Icon.

In his first interview since cracks in a 10th-floor precast concrete panel on Christmas Eve triggered the evacuation of residents from the 392 apartments in the newly completed Sydney Olympic Park building, Ecove founder Bassam Aflak said the problem was an "isolated issue" that did not cast a cloud over the builder and was no reason for him to stop working with Icon.