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ECCHO – Energy and Carbon Calculator for Homes 

A national online tool for calculating the thermal comfort, energy and carbon emissions of New Zealand homes


Nobody wants to move into a brand new home only to find it's actually not as warm, dry and efficient as they expected. We're working to take away the guesswork, with modelling offering a comprehensive assessment of a home's energy, carbon emissions, and thermal comfort from early in the design stage. 

To help you and your project teams we've built a simple online web app called ECCHO that allows you to not only see how your current design performs, but to experiment with all the different variables that influence energy demand and emission; from walls, roofs, floors, and windows, through to size, orientation, heating and hot water systems.

The latest version of Homestar (v5) has compulsory targets for heating, electricity and summertime overheating. ECCHO provides a pathway to demonstrate performance not just for Homestar certification, but is increasingly recognised by local councils for H1 compliance under the Building Code

The Government is expected to set similar performance requirements under the New Zealand Building Code. ECCHO is a great way to get up to speed with where our regulations are likely to head in future years 

Learn how to use it

While we've worked to make ECCHO as simple as possible, it's still a rigorous assessment of a home's performance. As such you'll need some basic knowledge before diving in.

The best place to start is our Homestar Designer course.

Throughout the seven week course you'll have the opportunity to use the calculator extensively and learn the basics of residential energy modelling.  Once completed, you'll also gain a one year license to use the software as part of the training fee.

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Meet Building Code energy efficiency requirements

ECCHO can assess the design of homes against the modelling method for Building Code H1/VM1.

Modelling with ECCHO is now being accepted by larger New Zealand councils without producer statements on the basis that the submitter has been trained, i.e. is a Homestar Designer. That means the same energy model can be used for both  your Homestar certification and building consent. 


ECCHO Licensing

Completing the Homestar Designer course includes a one year ECCHO license. Licensing renews annual, with a cost of $295 for members, and $435 for non-members.

ECCHO licenses can be bought separately from Homestar Designer training, though please note that only Homestar Designers may submit energy models as part of a Homestar certification.

If you would like an ECCHO license separate from Homestar Designer training, please contact the Homestar team

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View the ECCHO calculator