The facade of a block of flats hastily emptied by Housing New Zealand was so weak that a "large" person falling in the wrong place could have caused masonry to fall off the building, documents reveal.
A letter sent to Housing NZ the week after 131 residents were given just seven days to leave the Gordon Wilson Flats in Wellington reveals the facade had seriously weakened since concerns were first raised in 2010.
"In the worst cases it is even feasible that a large person falling heavily at a critical location would provide a sufficient force to dislodge elements," the letter from engineering consultants Clendon Burns and Park warned.
The letter followed a site inspection report that prompted the state housing agency to force tenants out of the 11-storey block in The Terrace at short notice in May last year.
In August, The Dominion Post revealed that the engineering firm first reported the safety concerns in April 2010. But the newly obtained letter shows that, after the tenants left, the risk was found to be even greater than originally thought.
"In addition to this ongoing problem of dealing with pieces of concrete falling from the building, these recent inspections have exposed an even more serious problem," the letter said.
In particular, concrete had cracked and fallen away around pins holding supporting columns in place, so that some columns and precast panels could fall away with a "large person falling" potentially providing enough force.
Housing NZ regional tenancy services manager Jackie Pivac said the finding was a worst-case scenario, and the agency had already "made the decision to relocate based on a more likely event occurring - such as strong wind or seismic activity".
No decision about whether to repair or demolish the building had yet been made, she said.
"Wellington has a high demand for housing. Our preference is to upgrade the building," she said.
"We are still collecting the information we need to make a decision re the future of the building."
Wellington Central MP Grant Robertson had earlier called for an explanation for tenants about how the building was allowed to get into such a bad state of repair.
- The Dominion Post