You can also determine how to make improvements that will make your home more comfortable, healthier and cheaper to run.

Carbon Dioxide Calculators

The CarboNZero Household Calculator is an online tool designed to estimate household carbon dioxide emissions.

By selecting which appliances, transport and home energy type your household uses, you can calculate how much carbon dioxide your home uses. You can also use the calculator to figure out how much impact different appliance/transport/energy use options would have on your home’s carbon dioxide emissions.

The CarboNZero Household Calculator was developed by Landcare Research. You can access the tool from CarboNZero website.

Energy use

Energywise calculator

The Energywise calculator allows you to figure out your home’s current energy usage and find out how much you can save by making changes. The calculator also features simple energy-saving tips.

Insulation calculators 

The Design Navigator website provides online tools for assessing thermal performance and insulation requirements for New Zealand homes.

Design tools

Google Sketchup is a software package for creating three-dimensional images of homes and buildings (or any other object). It can be useful for visualising the impact of a building on a site or visualising the amount of shade that might be cast by buildings, trees etc. You can download a free version from the Google Sketchup website.

Wall claddings

The life-cycle analysis of wall claddings tool, developed by BRANZ Ltd, provides data on environmental impacts of common wall claddings used in New Zealand homes.

The initial and life-cycle costs of the claddings are also provided. The tool enables the environmental impacts to be combined with the cost data to arrive at an overall 'score' for each cladding. The intended audience is designers and environmentally aware building owners. The tool can be downloaded from the life cycle - wall cladding page of BRANZ Ltd’s website.

Ecological footprint

The Ministry for the Environment’s website has an online ecological footprint calculator, allowing you to estimate your impact on the global environment. The calculator doesn’t just cover your home; it includes all aspects of your lifestyle - including such things as energy use, food consumption, transport, and purchase of goods and services.

Other overseas tools/calculators

There are many other online sustainable building calculators and tools available internationally. While these may offer guidance on sustainable building, they will not necessarily be applicable in New Zealand conditions. See the websites of Australian sustainable building tools BASIX and NABERS, or, for a list of other internationally available tools, the energy calculators and software page of the US Department of Energy’s energy efficiency and renewable energy website.

Note: the fact that this website links to other sites does not imply endorsement of any information or views expressed on them. See About Smarter Homes for more information about our policy on linking to external sites.