Councils are required to ensure they have enough residential-zoned land for current and future populations - and more land needs to be re-zoned, den Ouden said.
Subdivisions planned at Otamatea will provide another 380 house sites, enough to cater for 2.7 years' population growth. When further zoning changes go through for Springvale, another 650 sites will be available, catering for 4.6 years' population growth.
More house sites could also be made available through infill housing on larger sections, and through residential use of upper storeys in Victoria Ave, councillors heard.
The additional space for houses in Castlecliff could come available in seven years, and McDouall said work on extending Fitzherbert Ave is expected to begin in the next financial year.
The re-zoning will need a District Plan change, which will take at least 18 months, den Ouden said. Section sizes in the new Castlecliff areas would vary from 400 to 800 square metre minimums.
Water and stormwater upgrades will be needed to provide for the new houses, but developers could help pay for that.
Traffic, archaeology and cultural impact assessments will all have to be made before any re-zoning, den Ouden said. Certainty over provision of infrastructure will also be needed, and consultation with the public.
Cr David Bennett wondered why anyone would want to live "at the back end of Castlecliff", but the council agenda records the suburb is experiencing a resurgence and has increased housing demand.
Cr Rob Vinsen said the re-zoning was essential in the current housing climate, and fully supported it.
Councillors approved the preparation of the proposed District Plan change.
