Several approximations were made in the process of creating the map. The method for calculating wind zones in NZS 3604:2011 is a simplification of the method described in AS/NZS 1170.2:2011 Structural design actions - Part 2: Wind actions. The project aimed to see if the calculation of wind zones (in accordance with NZS 3604:2011) could be automated using GIS (geographic information system) software. Wind zones are an output from a 2014 research project at BRANZ. Wind regions and lee zones are our interpretation of Figure 5.1 in NZS 3604:2011. Microclimatic factors need to be considered in all locations. NZS 3604:2011 contains the comment: "For the purposes of NZS 3604, the corrosion protection requirements for structural fixings in exposure zones D and E are identical." the area within 100 m of tidal estuaries and sheltered inlets.īRANZ has not attempted to define precisely what is or isn't a tidal estuary or sheltered inlet, so our maps are technically conservative in those areas.īuilding Code compliance document E2/AS1 (2011) includes an exposure zone E, which is beachfront regions subject to rough seas and surf beaches.the area within 500 m of the coastline of New Zealand, including harbours.The zones relate to the severity of exposure to wind-driven salt, with B being low risk, C medium risk and D high risk. The corrosion zones in BRANZ Maps are our interpretation of the exposure zones in NZS 3604:2011. Three exposure zones - zone B, zone C and zone D - are shown on a map of the North and South Islands in Figure 4.2 of NZS 3604:2011. The zones are modified so that they better align with NZS 1170.5:2004 Structural design actions - Part 5: Earthquake actions - New Zealand.īRANZ Maps also include the changes to the zone boundaries in the Canterbury region introduced by the New Zealand Building Code clause B1 compliance document published in August 2011. The earthquake zones in BRANZ Maps are modified versions of those.
Four earthquakes zones - zone 1 to zone 4 - are shown on a map of the North and South Islands in Figure 5.4 of NZS 3604:2011 Timber-framed buildings.