The housing market downturn has hit a residential developer

Williams Corporation is offering redundancy to 10 to 30 per cent of its Kiwi staff, as well as those in Australia and Asia.

Founder, Matthew Horncastle says at the peak of the market last year it sold 800 houses in 12 months, aiming for 16-hundred this year.

He says it's only sold 500 houses in the rolling 12-months, and are over-staffed.

They're paying staff an extra months pay to take redundancy, and are planning to restructure its overheads.