Defence House Wellington

Defence House (Freyburg House) Deconstruction Project

Defence House, also known as Freyburg House, served as the headquarters for the New Zealand Defence Force and the Ministry of Defence. The building, a nine-storey structure with a basement, suffered significant structural damage during the November 2017 Wellington earthquakes, rendering it economically unfeasible to repair.

Situated in the heart of Wellington City, adjacent to key political and public service landmarks such as the National Archives and the Beehive, the building required a carefully planned deconstruction approach. Despite temporary engineering measures ensuring the building posed no immediate safety risk, the deconstruction demanded a controlled and low-impact methodology to minimise disruption to the environment and surrounding community.

Constructed to withstand extreme impacts, Defence House featured 1.2-meter-thick columns, reinforced gates, impact shields, bulletproof glass, and a secret command centre on the highest level, accessible only via a concealed elevator shaft not documented in the building's structural plans. The basement contained large diesel fuel and water tanks, along with self-sufficient generators, while the roof plant room housed nine hospital-grade air handling units and eight large water boiling units—some equipment having been installed just months before the earthquake and with minimal operational hours.

Nikau was entrusted with the following tasks, successfully delivering on each:

• Development of a Tailored Deconstruction Method: Crafting a unique approach to deconstruction that addressed the compromised state of the building while considering the sensitive nature of the project. The method employed a combination of core drilling, cut and crane, ultra-high reach, high reach, and heavy equipment techniques.

• Compliance with Council Regulations: Adhering to stringent council restrictions and traffic management requirements, which necessitated a compressed program for project completion.

Contractor Responsibilities:

• Utility Disconnection and Isolation: Ensuring all utilities were safely disconnected and isolated.
• Client Asset Retrieval and Salvage: Recovering and salvaging client assets from the building.
• Internal Strip-Out: Conducting a thorough internal strip-out of the multi-storey commercial space.
• Deconstruction: Utilising cut and crane techniques, high-reach demolition, and heavy machinery for efficient and safe dismantling.
• Site Clearance: Clearing the site post-demolition.
• Mass Recycling: Recycling concrete for reuse, adhering to sustainability practices.

Nikau’s meticulous approach and adherence to safety and environmental standards exemplify our commitment to delivering high-quality, sensitive deconstruction projects.

To see this project please click on the Video Link - https://vimeo.com/277739376