But, as RNZ reported in April, some buyers said it then tried to force them to pay tens of thousands more than the $636,000 maximum for an affordable home by saying they still owed them for basic landscaping like driveways and fences.
Auckland Council's manager of regulatory compliance, Steve Pearce, said it was charging Imperial Homes Limited and related companies Imperial Homes North West Limited and Imperial Garden Investment Limited with breaching the Resource Management Act.
The directors and sales agents would also be charged.
At the time, Imperial's legal counsel said it was entitled to charge extra for the landscaping because the affordable cap referred only to the "dwellings" themselves.
It said the extra charges had been made clear to buyers in sales and purchase agreements.
Under the Resource Management Act, the maximum penalty was $600,000 for the company and $300,000 or two years imprisonment for the individuals.
Some buyers had told RNZ they felt let down by Auckland Council and its failure to properly police Special Housing Areas meaning developers could get away with not upholding their end of the bargain.
But the chair of the council's planning committee, Chris Darby, said as soon as they became aware of the problem they took it seriously.
- RNZ