Building Performance - End of transition period

Building Performance - End of transition period


No images? Click here




End of transition period for “Good Ground” definition change

Kia ora koutou,

In November 2019, a change was made to the definition of ‘good ground’ within the B1 Acceptable Solution B1/AS1 to prevent it from being used on liquefaction-prone ground. The change to B1/AS1 directs those building on liquefaction-prone ground to select appropriate foundations for new structures. . We had allowed a transition period of two years starting from November 2019 meaning this change comes into effect from 29 November 2021.

To help councils, engineers and developers implement the changes MBIE developed some information to help compliance. This included;

·        Flowcharts showing compliance pathways for building consents submitted after 28 November 2021.

·        Simplified method for specifying foundations for NZS 3604-type residential buildings.

·        A summary for the assessment of liquefaction vulnerability at regional scale in accordance with the MBIE/MfE guidance (2017).

New resources to comply with B1/AS1

This Information will help councils, BCAs, engineers, architects and designers across New Zealand understand the 'good ground' change, assist mapping liquefaction-prone-ground in their region and support consistent design of resilient foundations when the changes come into effect at the end of this month.

For more information, please visit or email the Building Performance team at

Ngā mihi,
The Building Performance Team





Copyright © 2020. Ministry of Business, Innovation and Employment, all rights reserved. PO Box 1473, Wellington 6140

Preferences  |  Unsubscribe