David Corney and his builders have found their niche in preserving Wanganui's heritage buildings.

When Mr Corney bought DML Builders in 2003 it had six staff. During the economic boom that was up to 48, the recession shrank it back to 12 and now he has 26 men on the ground.

Most of them are renovating and shoring up heritage buildings in the Old Town and riverside part of central Wanganui.

He's been able to keep staff in work by starting Quay 11 Ltd in 2011. It's a commercial building investment company with two directors.


It now owns several buildings in the block bounded by Taupo Quay, Victoria Ave, Ridgway St and Drews Ave. They include the new Conservation Department building and the future Sarjeant Gallery replacements.

Mr Corney himself owns Embassy 3 Cinemas, the Victoria's Treasures building, a two-storey brick building behind George's Fisheries and an empty section in Ridgway St.

"I just saw that there was a need to go outside the square and be proactive, get things rolling," he said.

He was an early member of Wanganui District Council's Earthquake Prone Buildings Taskforce, and made contacts, learned from and contributed to that process.

"I think it's a lot of good people, passionate people, that sit around that table. We are streets ahead of other cities. We have the initiative," he said.

As a result of contact with the taskforce, Auckland University is funding nationally-important building testing in Wanganui, and Mr Corney is often asked for advice.

He is concentrating his building interests in Wanganui's riverside Old Town area, believing that is where the growth will be. He's watching it happen, and the pace could increase when the Sarjeant Gallery moves to L-shaped temporary premises there in April.

He's reasonably optimistic about the survival of the early 1900s heritage buildings that are "all Wanganui has got, other than the river". But their survival does depend on whether their owners can find tenants paying enough rent to fund the earthquake strengthening they need.

"The serious bit is, can the landlord afford to do it with the return he gets from the tenant? There's not many blue-chip tenants around."

After the first Christchurch earthquake in September 2010, Mr Corney was one of those scoping commercial building repair there for an insurance company. At the time he thought Government had overreacted in lifting strength requirements in the building code.

After the February earthquake in Christchurch and as the quakes continue up the island to Seddon and now Eketahuna, he's not so sure about that. He said Government may make the requirements more stringent still.

The Quay 11 upgrade of 34 and 36 Taupo Quay, turning the buildings into Conservation Department offices, cost $1.5 million. The company got an eight-year lease from a good Government tenant out of that.

Since that gamble DML Builders have also nearly finished strengthening the Kathmandu building in Victoria Ave and are hard at work preparing Taupo Quay and Drews Ave buildings to house the Sarjeant Gallery while its iconic Queen's Park building is strengthened.

The unreinforced brick masonry in the replacement buildings now has a concrete-framed diaphragm of columns and beams to hold and contain the brickwork. There's a new roof and a changed facade to come, and a two-storey building linking the Taupo Quay and Drews Ave buildings is under construction at the back.

The finished product will meet 67 per cent of earthquake strength required in the current building code. The upper storey of the Taupo Quay building will be temperature-controlled storage for art works, with display space and offices below and education space and workshops at the back and in the Drews Ave building. There's a separate tenant lined up for the upstairs of the Drews Ave building. After all that is done Quay 11 benefits from a seven-year lease for the gallery spaces.

New and cheaper strengthening methods, such as fibreglass rods, plaster systems and timber laminated beams are being used overseas and coming on stream in New Zealand - the sooner the better, according to Mr Corney.

Still to come for the DML team are strengthening for the Victoria's Treasures and Embassy 3 Cinemas buildings, and for the former Vega building by the Whanganui River City Bridge. It's now owned by Auckland's EQ Struc engineers, who were introduced to the city through the earthquake strengthening experiments.

Mr Corney's Ridgway St section will also get a building - when the right tenant comes along. It's an encouraging amount of forward work for the building business.

"It keeps DML surviving because it keeps me out of the tender market. You've got to think outside the square to keep a business running in Wanganui. I take my hat off to everyone that's in business in town. Everyone has got to fight for their living," he said.

Also to come is the next round of strength testing to happen on 35B Victoria Ave, the two-storey brick building behind George's Fisheries.

The testing will be funded by Auckland University and the results will be of both local and national benefit.

Testing on that building to date has revealed it is much stronger than anyone expected.

It will ultimately be completely destroyed and Mr Corney has a non-notified consent from the district council to demolish it.

Auckland University engineers are also looking for another large building to test to destruction - preferably one with walls of two layers of unreinforced brick masonry with a cavity between them.

"We need a live building we can put airbags in and force it to its breaking strain," Mr Corney said.