Moves to start earthquake strengthening Wellington's Town Hall is being welcomed by Heritage New Zealand.

This week the council has started exploratory work around the hall and Michael Fowler Centre.

Contractors are lifting up paving and inserting test equipment to help guide the building's new foundations.

Heritage New Zealand advisor Alison Dangerfield said the Town Hall is a "pivotal building".

"[There's] outstanding and special significance to it, and it's going to be a very important one to keep," she said.

Dangerfield said she's delighted work is now underway.

"We're very pleased for such an important heritage building that there's a commitment by the council and the citizens of Wellington to move ahead and strengthen it as it will hold onto the building into the future."