Cooper, made a Companion of the New Zealand Order of Merit this month, said the Canterbury quakes had forced big changes to building regulations and it had been traumatic to see how unsafe many old buildings were. "I think the Government had to react," he said.
The 15-year time frame gave people options, so no changes were being forced too fast.
"What's implemented is still the key question and it's not as though it would be an instant move," he said.
Some old buildings will have to be demolished, but those would include structures with minimal heritage value, Cooper said.
New Year Honours' notes said the Cooper and Company founder had financially backed the redevelopment and restoration of 17 historic buildings and new buildings in the Britomart Urban Restoration Project.
"Mr Cooper established the Britomart Arts Foundation, seeding an initial donation of $1 million, and donating works by New Zealand artists," the notes said, adding that The Landing, his rural property development in the Bay of Islands, involved the extensive creation of wetlands, native bush planting and preservation of areas of high archaeological value.
In 2008, Cooper was awarded the University of Auckland Business School Outstanding Maori Business Leader Award.