But the act was almost completely silent on the existing built environment and he cited a report on Christchurch's disastrous Bexley subdivision, ruined by earthquakes and liquefaction.
That report dealt with biodiversity and indigenous species "and three dam pages on trout and salmon yet Environment Canterbury identified it as being prone to liquefaction and earthquakes," he said.
Yet those treats were not identified in the document "and I'm sorry but it's one of step" he said of the RMA.
Smith also criticised scaffolding regulations on single-level dwellings but said health and safety issues needed to be taken into account.
The RMA was unresponsive and cumbersome in its attempts to deal with the complexities of different planning regimes, regionally and nationally, he said.
He cited an Auckland example where reserve land could be better used and of more amenity to a community but there was such a "diabolically complex process" to make any changes that nothing could be done.
"It makes it impossible for common sense...to build the best development," he said.
Smith acknowledged there had been 'some argy bargy" with Auckland Council over supply of land but paid tribute to Ree Anderson's Housing Project Office which he said had achieved considerable gains in uniting different arms of the council.
He also touched on topics of building material costs, control of residential land supply, liabilities and leaky buildings and covenants over land.
Penny Hulse, Auckland deputy mayor, said Auckland had so much new land opened up that it was the size of Hamilton.
She paid tribute to Smith but said people did not all want to live on Auckland's outskirts.
"People want to live where there's good urban environment, public transport and jobs. We need to be looking at the very expensive infrastructure we've got and absolutely make the most of that and that's why going up is better than going out," Hulse told the summit.
