HLC chief executive Chris Aiken said there was ongoing strong demand for the housing, especially at the affordable end.
Dr Smith said the decision to speed up the development and provide more affordable homes quickly would help address the shortage problems in Auckland.
"Hobsonville Pt illustrates the type of scale and momentum the Government wants to support and the type of development that Auckland needs to address its housing supply and affordability challenge."
Since earthworks began in 2013 at Hobsonville Pt, 716 homes have been sold, 157 at less than $485,000.
A spokeswoman for Dr Smith said the 30 per cent proportion in the three new areas did not mean the HLC could provide a lower proportion in other areas. The areas which are being fast tracked are Buckley B, the Village and apartments near Hobsonville Pt Primary School.
$550,000 is the maximum price the Government has agreed on for houses at the development to be categorised as affordable. Those are a mix of apartments, terraced housing and small standalone or semidetached homes which are only sold to New Zealand residents who agree to live in them for at least two years.
So far about 400 houses have been completed and occupied. The project will eventually hold 3000 homes. Prime free-standing homes cost just over $1 million and one-bedroom units sell for about $450,000. A further 1000 homes are in the pipeline and today's announcement will bring the total to 2500.
Dr Smith has been under pressure from Opposition MPs as Auckland housing prices soar and criticised for the slow rate at which other Special Housing Areas were being developed.
Labour housing spokesman Phil Twyford has also questioned whether $550,000 is affordable for lower income families. The Government agreed in May to increase the cap by $50,000 from $500,000 because of increased construction costs.
Dr Smith said those families were helped by steps such as low-deposit loans and the HomeStart deposit top-ups for poorer families buying houses of less than $550,000 in Auckland.
In the Budget, he also unveiled plans to use more crown land in Auckland for housing. He and Treaty Negotiations Minister Chris Finlayson are to meet with Tamaki Collective iwi to discuss the bypassing of the iwi rights of first refusal on the land.