The Government could be poised to announce joint ventures with big overseas developers to build large swathes of new developments

Thursday's Budget is expected to hold more announcements about Auckland housing, a message underlined by Finance Minister Bill English who this week said the Government stood ready to free up more Crown-owned land to ease Auckland's  pressures.

On Wednesday, Housing Minister Nick Smith confirmed houses could be built on Crown land including reserves, defence land and property once earmarked for schools and hospitals. Thousands of houses could be involved, he said.

The Government recently handed 2800 state houses in Auckland over to the Tamaki Redevelopment Company, which plans to turn 2500 of them into 7500 new homes.

However, if it chooses, the Government could go even further and adopt an option in a recent Business, Innovation and Employment Ministry (MBIE) research paper on housing affordability.

The paper discusses the difference between small-scale developments of 100 to 300 houses on surplus Crown land, and whole suburbs using Housing New Zealand land.

These 50 hectare-plus developments had the "potential to attract large offshore developers with extensive capital and expertise that would not otherwise invest in New Zealand," the paper said.

If undertaken they could "arrest price growth" in the Auckland housing market, and even lower prices, "especially if scale can supply lower-priced dwellings that the private sector isn't targeting".

The returns on small-scale developments were a "modest" 50 per cent of any profit, with the Crown contributing the land but deferring the sale, and developers contributing the rest.

However, returns from larger developments were "potentially high".

"Equivalent development vehicles in Australia have returned millions in annual dividends to their government owners," the MBIE paper said.

The paper said there was 70,571ha of Auckland land in public ownership, just over 27,000 of it by Auckland Council and 24,394ha by the Crown.

Housing New Zealand itself owns just 1,558ha.

The rest is owned by state-owned enterprises and Crown agencies, schools, Watercare and other services, or vested in reserves and parks.

Recently commercial real estate consultancy Colliers said i it expected more joint venture partnerships between  foreign and New Zealand property companies in future, although it did not say the Government would be involved.