Following a seismic assessment, it was found that the Heritage House Gallery was earthquake prone and of very high seismic risk relative to a new building. The assessment identified the following critical structural weaknesses:
- Chimney unreinforced masonry with some cracking present, with the possibility that the chimney could topple onto an egress route, in this case the emergency exit stairs.
- Unreinforced masonry walls double wythe with no ties. These walls are likely to collapse under face loads.
- No floor and roof diaphragms.
- Connections between walls and floors/ceilings have low strength and resilience (for example unrestrained floor beams).
- Gables unrestrained on upper level.
- There is potential pounding of the east wall against the 1978 concrete extension, resulting in damage.
To ensure public and staff safety the Heritage House Gallery was closed in March 2017 and all artworks displayed in the Heritage House Gallery were placed in storage.
Since the closure of the Heritage House Gallery, the Gallery has been working with a range of consultancies to develop plans to seismically strengthen the building and ensure the restoration and preservation of the heritage features of the building.
In October 2020, the Timaru District Council agreed to proceed with the project to seismically strengthen and restore the Heritage House Gallery.