The PwC building remains the tallest structure standing in Christchurch - but not for long. Kurt Bayer yesterday viewed its slow demise from the inside.

Towering 77m above central-city Christchurch, the damaged PricewaterhouseCoopers Building - too expensive to repair - oversees a city being torn down.

From the rooftop of the Armagh St glass office block, looking across the Canterbury Plains to the snow-dusted Southern Alps, the peace of the vista is broken by the constant hum of the demolition below.

What look like toy diggers and bulldozers clear the Crowne Plaza to the northwest, while almost all of Kilmore St, from Colombo to Manchester, is already gone.


Jackhammers chip, echo and reverberate to the south around Cathedral Square.

And below, about 40 demolition workers beaver inside the PwC building on what is the city's biggest demolition job.

Built in 1988 and 22 storeys high, it was slightly shorter than the Hotel Grand Chancellor - already "deconstructed" by the Canterbury Earthquake Recovery Authority this year.

But at 24,000sq m, it was the largest by land mass, and will take the British demolition experts, Arrow International, Nikau and Coleman and Company, about nine months to complete.

Their deadline is December 12, and since mid-March, they have stripped most of its contents.

Yesterday, when reporters were given a rare glimpse inside, it looked more like a squatters' residence than a proud and modern office block.

Pink spraypaint marks exposed electrical wires, air-conditioning ducts and walls, which are chipped, full of rough holes and barely holding up collapsed ceilings.

A musty smell hangs in the dark stairwells. Office chairs, covered in white dust, lie abandoned amidst piles of rolled up carpet and office folders.

Banging is heard above and below as workers continue to gut the building, preparing for the job of bringing it down floor by floor.

"The demolition is the reverse of its construction," says Canterbury Earthquake Recovery Authority lead engineer Carl Devereux.

He means that huge concrete panels which consist of the building's levels, will be cut up and plucked out by high-tech cranes.

Workers have started stripping the building from the top and the bottom.

They will meet in the middle floors, which sustained the worst of the damage in the magnitude 6.3 quake of February 22.

The concrete frames around levels 6, 7 and 8 were twisted in the shake, and the beams have "hinged", causing serious damage.

It would have been too costly for the building owners to repair, so they have opted for a Cera-controlled demolition.

"The building did what it was supposed to do," Mr Devereux says. "It took a long time to reach a decision [on demolition]. Engineers working for the owners went through numerous assessments and repair options.

"But this building is coming down for economic reasons - it was just too expensive to repair."

The middle levels have been propped up with wooden beams to keep demolition workers safe as after-shock earthquakes continue to rumble.

The top third of the building is being demolished using the "cut and crane method" while the last 14 floors will be dismantled using a high-reach crane, known as Twinkletoes, which will arrive about mid-August.

Small Bobcat diggers scoot about the upper floors on tracks, using large mechanical jaws to strip the building interior.

It takes a week to strip each floor and erect a scaffold hand-rail to pave the way for the next stage of removing its windows.

One of the biggest tasks is tackling the basement, which Mr Devereux says was the deepest in the city and housed a swimming pool, gym, and car-park.

The PwC building is one of about 220 Christchurch buildings more than five storeys tall.

Of these, 110 have been demolished, or are in the process of being brought down.

And from the PwC roof, the view of gaping holes in city blocks, running in each direction, is clear evidence of how far we've come.