Masterbuilders Federation chief Warwick Quinn said the peak would put huge pressure on his industry.
"I am not optimistic we would be able to grow our sector fast enough - we'd have to import labour."
If labour costs were high and land supply was not increased to contain values, it would be difficult to create more affordable homes, he said.
"The key component around house prices ... revolves around urban containment policies."
If a developer was building on a $500,000 section in Long Bay, they had to build a $500,000 house on it to make the project pay.
"So if you can produce land at $100,000, you can put a house on it for $150,000 to $200,000."