The Google quake checks: Street view used to find potentially at-risk buildings

Thursday, 22 November 2018

The Criterion Hotel building, housing Biddy Kate's Irish Bar, on Google Street View.

Buildings potentially at risk of crumbling over Marlborough's highways in another big shake have been identified - from the office.

The Marlborough District Council has been using 'smart maps' to identify possible quake-prone buildings, and then using Google Street View to take a closer look.

State Highway 6 is one of three major highways leaving Marlborough.

The council's smart maps offer basic property information, including decade of construction and resource consents, and an aerial view, while Google's street view allows a virtual roadside perspective.

Councils around New Zealand must identify quake-prone commercial and industrial buildings, and order owners to strengthen or demolish them within set timeframes, as new laws come into force.

A building in Christchurch which collapsed onto roads during the February 2011 earthquake.

State highways are essential for emergency services after an earthquake.

* Te Anau and Manapouri high risk areas as council looks for earthquake-prone buildings

* TDC to begin identifying critical routes and earthquake prone buildings**

The Criterion Hotel is one of nine buildings already listed as earthquake prone in Marlborough.

The Marlborough District Council has kick-stared the push by searching state highways 1, 6 and 63 to sniff out possible at-risk buildings.

Council senior building compliance officer Tony Adamson said his one-man assessment of the highways found three buildings to be a possible earthquake risk.

While Adamson could not name the buildings, he said two were along SH6 and one was along SH1.

'I look at smart maps for the aerial view it provides so I can identify properties along the state highways,' Adamson said.

'When a building is close to a road, I can use the same programme to get basic details on the property, such as property numbers.

'At the same time, I use Google Street View to look at the outside of the building and work out if the height of the building, were it to collapse, is within the scope of the road.

'If it is, then it could be a possible earthquake risk.'

The council's internal property system could uncover further information on a building, such as building materials used.

Adamson said he came up with the unique online method about four years ago as it was 'convenient'. He had been using it ever since.

'It would take me years to check out each building along each of our roads in person,' he said.

'A picture paints a thousand words. We're not looking for in-depth detail at this stage, we're just determining if there is a possible risk.'

Adamson said he also checked buildings along Kent St and Lagoon Rd, in Picton, as they led to wharfs, which were an important link for emergency services.

Once a building was identified as potentially quake-prone, a request was issued to the owner which asked them to supply the council with an engineering assessment of its seismic resilience.

Under new laws, the responsibility for organising and paying for an engineering assessment fell to building owners, rather than council, Adamson said.

A building was considered an earthquake risk if it was less than 33 per cent of the new building standard.

As a mostly high-risk area, the Marlborough region had five years to identify quake-prone buildings and two-and-a-half years to identify priority buildings, such as hospitals, schools and buildings along important routes.

If found to be quake-prone, the owner had 15 years to remove or strengthen the building or seven-and-a-half years if it was a priority building.

Owners would also need to display a notice warning the public of the building's quake-prone status.

The next stage, set to start 'straight away', would involve council uncovering quake-prone buildings along urban streets in Marlborough.

There were already a total of nine commercial or industrial buildings listed as earthquake prone in Picton and Blenheim as of September.

These included, in Blenheim, the Nativity Church, the Criterion Hotel and the Haddin Court Flats, and in Picton, the Picton Yacht Club Hotel and St Joseph's Catholic Church.

Criterion Hotel owner Terry Sloan said more than 50 per cent of the building's strengthening had been completed.

'We have also completed the retention of the URM [unreinforced masonry] walls for the street-facing walls to the public areas, which was a separate requirement that needed doing surrounding the URM act,' Sloan said.

'The remaining work will start shortly as we have just received the remaining drawings from the engineers for submission to [the] council's building department.'

Further down the track, the council would identify potential priority buildings not along urban roads or highways.

The council could also launch a public consultation of 'at least six months' to confirm which routes were of strategic importance to the community, and therefore could have priority buildings.

But Adamson said he thought a public consultation was unlikely as the region had been 'cleaning out' its stock of earthquake-prone buildings for years and had 'very few' remaining that could be at risk.

He also said about 99 per cent of buildings in Marlborough were timber-framed, making them exempt from the new process.

The new process followed the amendment of the Earthquake-Prone Buildings Policy in July 1, 2017, which required a fresh review of buildings under Ministry of Building, Innovation and Employment (MBIE) guidelines.

A council spokesman said the new amendment had been created with larger cities such as Wellington, Christchurch and Dunedin in mind.

'Wellington, for example, has many tall buildings and only one major road in and out of the city, which makes identifying earthquake-prone buildings a high priority,' he said.