The Reserve Bank of New Zealand has tweaked its 'speed limit' on low deposit mortgages by exempting loans used to fund new homes. RBNZ governor Grant Spencer said the exemption for all high LVR loans for construction of new houses and apartments would apply retrospectively from October 1."This exemption will help to support the supply of new housing and, in doing so, reduce some of the pressure arising from excess demand in the New Zealand housing market," Spencer said.In a Questions and Answers paper issued with the announcement of the exemption, the bank said it had changed its view that the limit would not have a major effect on new housing supply after feedback from banks and the building industry."The information suggests it may be more significant than previously thought," the bank said, adding that banks had said they were less likely to prioritise high LVR lending for new builds within their 10 per cent limit because of the greater uncertainty and complexity associated with such loans.The Reserve Bank said the exemption would not apply to renovations or extensions to existing homes, or to homes already built on 'spec'.