Check out the government's HomeStart grant if you're looking to buy your first home. To qualify for a HomeStart grant you'll need to have been contributing to the PSS (or a KiwiSaver scheme or complying superannuation fund) for three years or more. The grant is administered by Housing New Zealand and does not come out of your PSS funds. You do not have to pay back the grant in most circumstances. Grants are subject to price caps, which vary geographically, and income caps.
Find out more at Housing New Zealand.