Earthquake Risks Identified in Council Buildings

Further investigations are to be done on five Council buildings following an initial evaluation of how well they would stand up to an earthquake.

Tonight’s (1 May) Monitoring Committee meeting heard that of eight key Council buildings, four were identified as being of potential earthquake risk, and one – the original portion of TSB Showplace – has been ranked as earthquake-prone.

The committee noted that more detailed structural assessments are being done on TSB Showplace and also on the Govett-Brewster Art Gallery, the next lowest-rated building.

Further assessments will also be done on three other buildings – Oakura Town Hall, Inglewood Town Hall and Puke Ariki’s South Wing – to identify the feasibility of bringing them up to 67 per cent of the current building standards.

In December last year the Council adopted a policy for identifying earthquake-prone buildings and specifying timeframes for property owners to address any issues.

“Under this policy we undertook an initial evaluation of eight Council buildings in Oakura, Inglewood and New Plymouth,” says Manager Property Peter Handcock.

“The Building Act states an earthquake-prone building has less than one-third of the seismic bracing strength required of a new building designed to current codes, and so is considered unacceptably unsafe in an earthquake.

“The Opera House part of TSB Showplace has a score of 26 per cent, and the Govett-Brewster is close to that one-third threshold with 36 per cent. We’re taking a closer look to confirm the situation and identify options to strengthen them.”

The eight buildings investigated were:

• TSB Stadium: 140 per cent of new building strength.
• Puke Ariki North Wing (museum): 113 per cent.
• NPDC Civic Centre: 68 per cent.
• Inglewood Town Hall: 62 per cent.
• Oakura Town Hall: 56 per cent.
• Puke Ariki South Wing (library): 42 per cent.
• Govett-Brewster Art Gallery: 36 per cent.
• TSB Showplace (original section): 26 per cent.

 

The New Plymouth Opera House was built in 1925 and the oldest portion of the Govett-Brewster was built in 1918 – both well before design standards for buildings in earthquakes were developed in 1935 as a result of the Napier earthquake.

TSB Showplace is listed as a category A item in the District Plan and a category II building with the Historic Places Trust – one of four registered opera houses in New Zealand.

Initial evaluations will also be undertaken on the Downtown Car Park, Yarrow Stadium, Te Henui Vicarage and Civic Centre stairs.

The New Zealand Society for Earthquake Engineering recommends that buildings should meet 67 per cent or more of the new building standard. The Council’s policy is to encourage owners to strengthen their buildings to this level.

• Following the introduction in 1935 of design standards for buildings in earthquakes, further changes came in 1965 with the identification of three different earthquake zones, and in 1976 which allowed for more variation in seismicity over New Zealand. There were further refinements in 1984, 1992 and 2005.