
They are often used in a variety of combinations. These tools can be used in various ways to inform successful design and management actions. These values can be used in conjunction with clause E1 of the Building Code.Understanding the Urban Context and Character Rainfall intensity values are sourced from NIWA's HIRDS calculator and correspond to a 10-minute rainfall intensity with an annual probability of exceedance of 10%. Climate zonesĬlimate zones are our interpretation of Figure B1 in NZS 4218:2009 Thermal insulation - Housing and small buildings. Initial user testing has shown that the wind zones in BRANZ Maps are likely to be inaccurate near escarpments or cliffs.Ī description of the method used and a comparison with the few existing council maps can be found in Build 147. Therefore, the wind zones must be treated as indicative and used only as a reference when calculating site-specific wind speed or only in the absence of more reliable data being available.įor example, an up-to-date council-wide wind zone map would be considered higher-resolution data, and a site-specific wind zone calculation would be higher still. 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."
Dunedin webmap code#
