Nelson City Council has for Heritage Properties has: Zero fees for resource consents, Rates Remissions for Heritage Maintenance and a Heritage Project Fund. Heritage Property Ownership.
And a nifty easily navigated website for Heritage and History...
http://www.stuff.co.nz/nelson-mail/entertainment/8567312/Double-anniversary-fun (Link to Nelson Mail Article)
And lets not forget the Design Guidelines for Elliot Street (Elliot Street is a Nelson Heritage Precinct)