SR391 The cost of Homestar: A case study on how to achieve a 6–10-Homestar rating for stand-alone and terraced housing in Hobsonville Point (May 2018)

This research performed a desktop analysis of 10 Building Code-compliant stand-alone and terraced residential designs to determine the additional capital cost investment required to achieve the higher levels of Homestar. The designs analysed were selected from the Hobsonville Point submarket and had not considered Homestar in their basic design.

This report has a narrow focus, reviewing only the costs and benefits of Homestar that can be readily quantified. The benefits considered only relate to energy and water use savings and do not consider other benefits such as health, resale value, comfort, quality or resource depletion. It is acknowledged that the choice to include ‘green’ features in new housing is not made solely or even predominantly on cost-saving measures. Hence, the results in this report are only one part of the decision-making process.

The results show that Homestar version 4 (v4) has greatly reduced the capital cost of achieving the different levels of Homestar ratings compared to previous Homestar assessment (Homestar v2 and v3), with a 6-Homestar dwelling costing approximately 4% more to construct than basic Building Code-compliant dwelling.