The opening date of the new Hotel Grand Chancellor in Christchurch has been pushed back...but only slightly.

The 12 level high-rise hotel, office and retail complex will be built on the hotel's original site on Cashel Street, in the CBD.

The 70-metre building was the tallest in the city, before it was demolished following the February 2011 earthquake.

General Manager Frank Delli Cicchi says work is underway on the detailed design phase, but due to some final amendments to the plan it won't be open by the end of next year.

A target date has been set for the first quarter of the following year.