More information about the 2 hectare rule under the NES
Most urban areas in New Zealand experience air pollution during winter. Our focus is on improving air quality in those areas. Urban areas typically have smaller property sizes and as there is no nationally consistent definition for an urban environment, a property size of less than 2 hectares was used. The standard two hectare rule applies throughout New Zealand including rural areas.
See more information at http://www.mfe.govt.nz/air/national-environmental-standards-air-quality