Half a dozen staff from main construction contractor Naylor Love Construction Ltd and excavation contractors on behalf of Ngai Tahu Property Ltd will begin digging to a depth of 3m across three-quarters of the site over the next three weeks to form the basement car park.
The car park would be accessed from Camp St and a three-storey block built on top.
There will be retail space on the ground floor of the so-far unnamed block, with office space on the first and second floors.
The building will take up the full site with an outside courtyard opposite the Pig and Whistle pub.
Starting in October, a tower crane will be site for six months.
The Post Office Precinct will be completed by the end of October next year.
The New Zealand Post Office will relocate to its new premises on November 1, 2009.
