Earthquake strengthening of Wellington's 114-year-old town hall is about to get underway.

In the next two weeks, work to secure its brick parapets and facades will start before the main refurbishment begins later in the year.

The building has been closed since 2013 and is set to reopen in 2021 as a joint facility between Wellington City Council, Victoria University's New Zealand School of Music and the New Zealand Symphony Orchestra.

Wellington Mayor Justin Lester says "The town hall has been at the centre of the city's civic and cultural life for generations, and now a three-year journey will start to bring back the hall."

The hall is one of a number of heritage buildings around the city centre that need work to make sure the public is protected from the risk of falling masonry in an earthquake.

The council was working with building owners to deal with unreinforced masonry around the city, Mr Lester said.

This followed a central government decision after the Kaikoura earthquake to take action to secure masonry on buildings in busy urban areas that are vulnerable in a quake.