The Oxford Apartments, built in 2005, were designed by well-known architecture firm Warren and Mahoney. Standing tall on the banks of Christchurch’s Avon River, they were at the time one of the tallest and most distinctive buildings in the city. While many of the city’s buildings were damaged beyond repair in the February 2011 earthquake, the Oxford Apartments remained standing. However, a post-quake Design Features Report saw the building as having a seismic rating of less than 34% NBS.

Its future bleak, the building was written off by its insurers and languished until 2018, when it was bought by a developer who presold a number of apartments for several millions of dollars each. The building was saved and today it offers a “luxury collection of unique and exclusive residences… [notable for its] unsurpassed craftsmanship and meticulously curated natural materials and finishes”.

Dominion Constructors separated out several packages of work as part of the upgrade to the building. Contech’s role was to install vertical post-tensioning to increase the lateral capacity of the structure under earthquake loadings. Core holes were drilled vertically through the columns and eight BBR CONA CMI multi-strand post-tensioning tendons (four tendons with 8 strands, two tendons with 14 strands and one tendon with 21 strands and one tendon x 31 strands) installed over the full 37m height of the building from top to bottom. BBR Contech supplied and detailed top- and bottom-end anchorage hardware and this was followed by tensioning using 300T and 700T multi-strand stressing jacks. Once this was complete the tendons were grouted, and caps were installed at the top anchorages for corrosion protection of the anchor heads.

Today it’s great to see the building once again standing strong on the city’s landscape – an ‘architectural icon’ that offers the best in inner-city apartment living. And with its seismically stable foundations and ‘Grade A+’ seismic design, it will stay upright and safe for many years to come.