Its budget may have blown out by almost a third more than the original figure, but this weekend the doors to the Christchurch Town Hall will re-open for the first time since the 2011 earthquakes.

It was touch and go whether the 47-year-old building would even be repaired due to major damage but $167 million later and the city is finally getting its town hall back.

RNZ was allowed inside for a sneak peek ahead of Saturday's official opening.

The repair of the 1972 vintage building has very much been a restoration job with all of the original decor replaced, keeping with the original design.

Chris Wallace from V Base, the company managing the Town Hall, said everybody in Christchurch had a close connection to the building.

"I had graduations here and did Cantamath competitions here and came to concerts here, so it's pretty amazing to think that we're close to getting it back for the city."

Photo: RNZ / Simon Rogers

Opened in 1972, the Warren and Mahoney designed building employed brutalist architecture and pioneering acoustics that made it one of the top concert halls in the country at the time.

Then prime minister Jack Marshall commented at the opening on its striking looks.

"This town hall complex could not have been built like this in any earlier decade. The bold firm decisiveness of the exterior, the modern miracles of light and sound, the glowing wood, the range of colours, combine to make this a monument for our own time."

Photo: RNZ / Simon Rogers

Mark Gregory remembered the day it opened and for a time conducted school children in various choirs there.

The thing he missed the most about the place was the acoustics.

"This is very special I think, particularly in Christchurch. And having had to attend concerts in the Horncastle Arena where all of the orchestral instruments [have microphones], to be able to hear them naturally is going to be superb."

Photo: RNZ / Simon Rogers

Mr Gregory's father also had a close connection to the place.

"One of the jobs that he did here ... was to record all of the messages for intervals, and it was always a bit disconcerting being in the bathroom and all of a sudden you'd hear your father's voice saying, 'Ladies and gentlemen would you please now return to your seats'."

The Town Hall would be opened in stages starting with the main auditorium, foyer and function rooms this weekend, followed by the smaller James Hay Theatre in March and facilities for the Christchurch Symphony Orchestra in August.

There would be two open days for the public from 12 noon until 6pm on Saturday and Sunday.