Climate
- Picture: APN Ltd
To get a comfortable, efficient, durable home you’ll need to consider the climate.
Sun, wind, rain, temperature and humidity will all influence your enjoyment of a property and the design/construction of any new home or renovation.
By taking climate into account, you can:
- get a more comfortable home with lower heating and cooling costs
- ensure your home is weatherproof and durable
- ensure your home is strong enough to stand up to the elements.
It’s worth considering climate before you buy a property or before you start the design process. Your local or regional council should have information about local climate conditions. It’s also worth talking to neighbours.
Temperature
Check the temperature range, in both summer and winter, during the daytime and at night. This will influence how much attention you’ll need to pay to heating and cooling.
It will also influence how much insulation you need. If you’re designing a new home or renovation or even minor alterations, you can use passive heating and passive cooling to make your home more comfortable and energy-efficient.
Sun
Ideally, your home will get plenty of sun in winter or in cooler climates, but not too much in summer or in warmer climates.
Access to sun is affected by the site’s shape, slope, and obstructions such as trees and other buildings. It’s worth considering all of these factors when you look at how much sun the site will get at different times of day in summer and winter.
See orientation for more information about positioning a home to make the most of the sun.
Humidity
The more humid the climate, the more likely you are to have problems with moisture and condensation in your home. It’s worth checking the relative humidity in winter and summer.
Rainfall
The amount of rainfall, its intensity and the direction it comes from will influence the design of your home or renovation. The higher the rainfall, the more likely you are to have problems with weathertightness and with moisture and condensation.
High rainfall (especially intense rain storms) may also create issues with ground stability and stormwater runoff.
Wind
Wind direction, strength and seasonal variations will affect the structure and design of your home or renovation. Exposure to wind will, for example, influence window and door placement. Weathertightness problems are likely to be worse in high wind areas driving water through cracks.
Wind will also affect your enjoyment of outdoor living.
See orientation for more information on how wind influences design.
Wind zones
Wind creates horizontal forces on buildings. Any building needs to be braced to withstand these forces.
If you’re planning a new home or extension, your designer or engineer will need to determine the property’s ‘wind zone’ - i.e. the forces that will affect the building.
Your property could be classed as being in a low, medium, high or very high wind zone, or it could be classed as needing a ‘specific engineering design’ to cope with wind forces.
The wind zone will determine how strong any building needs to be, what materials should be used, and how it should be maintained.
The designer or engineer will take into account:
- wind region - New Zealand is divided into two wind regions)
- lee zone - some parts of New Zealand are classed as 'lee zones', which means they receive some protection from wind
- topographic class - wind speeds up as it passes over or between hills, or through valleys (this is the 'wind tunnel' effect)
- ground roughness - wind slows down as it goes over rough terrain
- site exposure - other buildings or landforms can provide protection from wind; your property will either be classed as 'exposed' or 'sheltered'.
For more detailed information, see the ConsumerBuild website’s page on environmental zones, or New Zealand Standard 3604:1999 Timber-framed buildings.
Snow
If your property is in an area with heavy snowfall, your roof and other parts of your home’s structure will need to be strong enough to cope with this load. Snow loading can affect the design of lintels, rafters, ridge beams and verandah beams on your house.
Your engineer or designer will work out the snow loading.
For more detailed information, see the ConsumerBuild website’s page on environmental zones, or New Zealand Standard 3604:1999 Timber-framed buildings.
Corrosion
All homes in New Zealand are classified into corrosion zones, reflecting their exposure to sea spray and geothermal areas.
This zoning affects the materials you will use to build your home or renovation - especially claddings, metal fastenings and flashings. For example, steel fastenings will corrode or rust more quickly than stainless steel fastenings when exposed to sea spray.
The corrosion zone will affect the guarantees manufacturers offer on their products.
For more detailed information, see the ConsumerBuild website’s page on environmental zones, or New Zealand Standard 3604:1999 Timber-framed buildings.
Microclimate
An individual site’s temperature, humidity, wind and rain may vary from the prevailing regional climate. The microclimate can affect the energy performance of a building and types of vegetation that can be grown.
For example, check for areas that are sheltered from prevailing winds, obviously dry or wet, where heat seems to collect either from exposure to sun or from nearby heat sinks such as walls and areas of concrete.
Microclimate is also affected by topography, adjacent buildings, vegetation, bodies of water (including small creeks) and slope. These can all have an impact on air movement and access to sun.
Climate change
Before you buy or build on a property, it’s worth considering how the site will cope with:
- severe wind and rain storms and associated flooding
- floods
- dryer summers
- wetter winters
- a rise in sea, lake or river levels.
More information
From Smarter Homes
From other sites
You can buy the relevant standards from the Standards New Zealand website.
The MetService website’s learning centre and the National Institute of Water and Atmospheric Research’s national climate centre have information about New Zealand’s climate and climate data for various parts of the country.
Your local council may have information about the local climate. ConsumerBuild’s council finder web page will help you find your local or regional council.
