The policy would result in a couple earning $75,000 being $200 a week better off than under National's housing policy, Mr Cunliffe said.
"A $200 a week difference in mortgage repayments is huge. It is the difference between realising the dream of home ownership and facing years of renting.
"Labour's policy will help 50,000 families over five years buy a first home. National's will only give a slightly higher deposit to 40,000 families," Mr Cunliffe said.
Labour would also tackle property speculation from non-residents by amending the Overseas Investment Act to close a loophole which made New Zealand an easy target for overseas speculators, Mr Cunliffe said.
New restrictions would be also applied on the purchase of residential property by non-residents so that they would only be granted permission to purchase a residential property if they intended to live here permanently or if the purchase added to the country's existing housing stock by buying a new home, he said.
Labour's housing spokesman Phil Twyford said KiwiBuild would deliver the equivalent of a Hobsonville $485,000 two-bedroom terrace home for $360,000 by forgoing the developer's margin on the land cost ? saving $36,000 and a further $89,000 would be saved by using off-site manufacturing, bulk buying building materials and reducing builders' margin through high-volume tendering.
The process would drop the build cost from $3389 per square metre to $2400, Mr Twyford said.
"When you're building at scale - when you're building 10,000 houses a year, you can do deals that drive down the cost of building materials.
"Currently, Kiwis pay 30 per cent more than Australians do for the same building materials so we know that we can really push down the cost of building materials.
"Also, in some cases with KiwiBuild the Government will be the developer, that's how we'll get better control over land costs and for the units we're talking about today, we think we can knock 20 per cent off the cost of the land."
"The other way we can really drive the cost down is through off-site manufacturing and by the scale of KiwiBuild we can tender that work out to companies that can really crank up their capacity, build factories [and] make better quality houses at a much more cost-effective price.
"There are several companies in New Zealand who are already doing this who are itching to crank up capacity.
"The Germans do it, the Scandinavians do it, the Americans do it, it's actually time that we did it."
Cunliffe defends case-study hiccup
David Cunliffe is defending the organisation of Labour's election campaign after a couple used as a case study for the party's housing policy conceded they weren't actually looking to buy.
The Labour party leader and the party's housing spokesman Phil Twyford confirmed Labour's KiwiBuild policy at a housing development in Hobsonville today with a young couple who Mr Cunliffe said would benefit from the policy.
Mr Cunliffe introduced Jordy Leigh, 20, and Harrison Smith, 22, as "a young couple who make about $75,000 a year".
"They've looked at buying a home, but they could never afford one. Just to get a 20 per cent deposit on one of the homes around here would mean saving $100,000.
"They took another look when National announced its deposit subsidy policy, but because National failed to mention that the repayments on a mortgage are simply unaffordable, they are now looking again," he said.
Ms Leigh said they were currently living with her parents in Point Chevalier and although they had "had a look at houses in the Auckland area," she conceded they weren't actively in the market to buy.
"We haven't actively been looking for a home to buy in the near future - that's definitely not our goal - our goal is to have a home in a few years, we're trying to start a family.
"So, not actively looking, but aspiring to have our own home, definitely," Ms Leigh said.
"We would not be able to get one next year under KiwiBuild, we would have to wait a few years, but the ability to be able to buy a house eventually is something that is invaluable to us."
Ms Jody then declined to reveal any political affiliations the couple may have but said she was an EPMU member.
Mr Cunliffe later stood by the suitability of the couple, describing them as "perfect".
"They are a genuine couple who are being locked out of the market by high deposit rates.
"They are thinking about getting a house....of course they are planning to get one because they're expecting their first child and they're desperate to get their own home."
