A proposal by the New Zealand Government for seismic assessment of buildings could have them, and cities, looking very different within just a few years.
The Government consultation document recommends local councils assess a list of earthquake-prone commercial and high-rise, multi-unit buildings, with a focus on those built before 1976, within five years, reports The New Zealand Herald.
Around 193,000 properties will be assessed, with an estimated 15,000 to 25,000 buildings needing to be strengthened or demolished in a 10 year period if they cannot withstand a moderate-size earthquake.
These proposals on seismic strengthening are in response to the Canterbury Earthquake Royal Commission report on earthquake-prone buildings and could cause many well-known buildings to have added design features.
Institution of Professional Engineers chief executive Andrew Cleland says earthquake bracing or strengthening elements on buildings could be exposed to reassure people that they are entering a strong building.
New design features of seismically safe buildings could include exposed cross-bracings, visible steel beams in ceilings, ply to secure unreinforced brick made obvious and damping systems at the top of buildings to absorb earthquake energy.
There is also the possibility of steel bolts driven through old facades becoming a feature. Although some will seek to disguise these in the hope of retaining architectural aspects of the old buildings, Mr Cleland says.
Results of strengthening will be variable, he says, some people will hide the elements, yet some will want to show them off.
“It will be down to the individual building owner or architect, to what extent they want to use extra strengthening as a feature.”
However, Auckland City Council believes the proposals could mean an execution order for heritage and character buildings as landlords may not have the money required to strengthen earthquake-prone buildings.
Landlords could either knock them down or board them up and walk away, something which currently plagues the United States in areas that have experienced economic downturn.
An example of the issues faced is Wellington’s Cuba Street – many of the buildings along the iconic walk are earthquake-prone and already need to undergo work in order to meet seismic building standards.
A group of fourth-year Victoria University students looked into the cultural street and made recommendations for many of the 72 heritage buildings.
Although there were recommendations on how to preserve and strengthen buildings, around 25 per cent of the heritage buildings were selected for demolition because of limited heritage value and poor maintenance.
