Defence House Wellington
Defence House (also known as Freyburg House), the headquarters of the New Zealand Defence Force and Ministry of Defence, sustained structurally critical damage during the November 2017 Wellington earthquakes making the nine storey building (plus basement) uneconomical for repair.
Located in the heart of Wellington City and a stone’s throw from the country’s political and public services precincts (the National Archives and Beehive located just across the road), while temporary engineering meant the building was not an immediate health and safety risk to the public, the proposed deconstruction required a controlled, low risk method with minimal impact on the environment and people.
The building was constructed to literally withstand a bomb blast, with 1.2m thick columns, reinforced gates and impact shields, bullet proof glass and a secret command centre on the highest level accessible only by a secret elevator shaft, it’s presence not recorded on any of the building’s structural drawings and a surprise to contractors when discovered.
The basement had large diesel fuel and water tanks and self-reliant generators, enough to provide its inhabitants for whatever contingency. The plant room on the roof housed 9 hospital grade air handling units and 8 large capacity water boiling units. All plant and equipment had only been installed months before the earthquake, some equipment have little as 45hrs on its meters.
Nikau was tasked with and successfully completed:
Developing a unique method of deconstruction, accounting for the already compromised state of the building that acknowledged the sensitive nature of the project and effect on members of the public, surrounding businesses and apartment owners – the method employed used a combination of core drilling, cut and crane, ultra-high reach, high reach and heavy equipment deconstruction
Council restrictions and traffic management dictated a compressed program for completion
Contractors Responsibilities
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Utility disconnection / isolation
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Retrieval client assets / salvage
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Internal strip out multi-storey commercial
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Deconstruction – Cut and Crane
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Demolition - High Reach
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Demolition heavy machinery
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Site clearance
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Mass recycling concrete for reuse
To see this project please click on the Video Link - https://vimeo.com/277739376
