The government will impose a maximum income cap restricting who is eligible to buy a home under its KiwiBuild programme, RNZ understands.

Photo: RNZ / Richard Tindiller

Cabinet signed off on the eligibility criteria on Monday and Housing Minister Phil Twyford is to reveal them at an official announcement in Auckland on Wednesday morning.

One of the conditions will be an income cap, despite the government previously downplaying that prospect, a source has told RNZ.

Mr Twyford declined an interview request and his spokesperson refused to confirm or deny the story.

The government has already confirmed the houses will be available only to first-home buyers and people in a similar financial situation.

Other restrictions could include the length of time a person is required to live in the home before renting or selling it.

Labour's policy ahead of the election was that any capital gains would need to be handed over if the house was sold in the first five years.

KiwiBuild houses in Auckland and Queenstown will have a maximum price of $650,000 for a three-bedroom home, $600,000 for a two-bedroom home and $500,000 for one bedroom.

Across the rest of the country, the maximum price will be set at $500,000.

The KiwiBuild policy aims to construct 100,000 affordable homes over the next 10 years. The government's beginning with a target of 1000 houses over the next year and another 9000 by 2021.

From this week, aspiring first home-owners will be able to register their interest online.