Prime Minister David Cameron announced a national housing campaign on Wednesday to help young families climb onto the housing ladder.Addressing the Conservative Party's annual conference, he described housing as one piece of unfinished business in the economy, Xinhua reported."A greater Britain must mean more families owning a home of their own," he said, adding 600,000 new homes have been built in the last five years.The price of the "starter homes" will be capped at $382,000 across the country and in London where property is more expensive the cap will be 450,000 pounds $688,000.The campaign was expected to see 200,000 new homes built by 2020, a Cameron spokesman said later.Cameron's hour-long speech brought the conference to a close.