Christchurch real estate agents say National's latest housing policy would draw first home buyers into the central city.

The party said it would double the amount of money available for the grant, which is currently $20,000 for couples looking at existing homes and $30,000 for new builds.

The Real Estate Institute's Canterbury Director, Jim Davis, said the policy would give first home buyers in Christchurch a huge amount of options.

He said in the current market, they could afford a house in almost any area of the city, or a new apartment in the middle of the CBD.

"As more and more apartments are being built in Christchurch and closer into the city, a lot of them are in this price bracket that a first home buyer can afford to purchase it."

Jeremy Meachem of First Place Mortgages said when the grants were last increased, Housing New Zealand was flooded with applications.

"Housing New Zealand were inundated with applications and flooded. So I would anticipate this would be equally received if it transpires."