A ban on frameless toughened glass being used around decks as any type of barrier or balustrade is being fast-tracked due to fears because the panels break too easily.
Auckland Council is pushing government officials to fast-track a national building standard making solid rails on the barriers compulsory - a change made in Australia 10 years ago.
Auckland Council is pushing for a nationwide ban on frameless toughened glass balustrades. Photo: 123RF
The council has been carrying out its own tests, which it says reveal that sharp knocks on the edge of frameless toughened glass panels can shatter them into tiny pieces.
"We've done some research and looked for anyone who's been injured as a result of a frameless toughened glass balustrade breaking, and we haven't found any evidence to that effect," said Ian McCormick, the council's general manager of building control.
"But we're certainly aware that from time to time these glass panels do break. An interlinking rail protects the edge and also continues to provide a form of a barrier - that's why we are keen to err on the side of caution."
But the glass industry is questioning the rush, given there have been no injuries.
Changing a standard would usually take six to nine months, but this one, published for feedback at the end of February, could be in effect by 1 June.
Anyone with frameless balustrades already in place, or that they have a building consent for, would not have to change them.
Mr McCormick said that did not mean public buildings or the likes of hotels with frameless balustrades on high balconies should not voluntarily add railings.
"I would recommend that, you know, they look at the new standard and they consider interlinking rails on the barriers. I just think it's a safer way of avoiding, you know, potentially, somebody getting injured."
The council is also now recommending to people applying for building consent that they consider changing their design to include interlinking railings.
Fast-track not warranted - industry
Though the Glass Association backs a nationwide change, it questions the speed.
Director Stewart Knowles said glass makers and installers had only known about this for a few weeks, and to add to the pressure it was proving very tough trying to engineer the rails to meet the new standard.
"These safety concerns are not new. We have known about this for a long time as have MBIE [Ministry of Business, Innovation and Employment] and lots of other parties," said Mr Knowles.
"MBIE had the opportunity at any time to change the Building Code and to make it a requirement. And obviously at that time MBIE was comfortable to leave the rules and regulations how they were."
Mr Knowles fears Auckland Council might succeed in getting the ministry to fast-track the change.
"There haven't been any injuries to really warrant this being fast tracked. We support what's happening, it's just the speed of it we're worried about."
He said putting railings over existing frameless balustrades would not be simple, because of that complex engineering.
Under the changes, balustrades will still be able to use frameless laminated glass, which, like windscreens holds together when it shatters - but it is more expensive.
In Australia, a decade of a ban on simple toughened glass has led to frameless innovations such as a product called sky glass that stays rigid after it breaks.
Architects in New Zealand here have been discussing the move online.
Architects Institute president Pip Cheshire said if there was hard evidence of death or injury there would be no debate about changing the standard.
"I guess what I have observed from the informal conversations on the chat list is that there's a sense that we might be chasing phantasms ... that there will be considerable cost pursuing something for which there's no clear argument in favour of improving the standard."
RNZ News knows of one glass specialist who will not lean on a balustrade because microscopic flaws within them can mean they suddenly shatter.
And Mr Cheshire said toughened glass was problematic because if it warmed up unevenly, the differential heating could cause microscropic flaws to fracture.
Personally, he would not mind if he never saw another frameless balustrade.
"People say, 'well, I've got a balustrade but I don't actually have one, you can see right through it.' And I find that a bit of a nonsense really. Far better, to my mind, if they have some sort of capping on it."
MBIE said it would come back to RNZ News about the balustrade change later today.