The maximum price for an affordable home at Auckland's Hobsonville Point is set to increase to $650,000.

Photo: RNZ / Todd Niall

Under the city's Housing Accord, 20 percent of the homes in the development are to be made affordable.

That had meant they were priced at $550,000 or below, but from July the maximum go up by $100,000.

Chris Aiken, executive of the government-owned Hobsonville Land Company, said it was due to building costs and people wanting larger homes.

"Construction costs have gone up a bit, and we are finding that some first home buyers and access buyer were actually looking for three bedrooms and the ... previous cap didn't allow for that."

Homes will still be available for $450,000 and $550,000, he said.

So far 422 affordable homes have been sold.

Income caps will also be adjusted to line up with the KiwiSaver HomeStart grants.

The Housing Accord was set up in 2013 to address the city's housing shortage.