Last year it was double bunking; now this year's solution to rocketing demand for prison beds is "pop-up prisons".
The Department of Corrections has put out a tender for three "modular accommodation units" to house an extra 378 inmates at Rolleston and Tongariro prisons.
Just three months ago former Corrections Minister Judith Collins dismissed the notion of "pop-up prisons".
"I predicted in December last year about pop-up prisons being built," Labour MP Kelvin Davis says.
Ms Collins responded to Mr Davis with a tweet: "No truth in K Davis' PR that Corrections now doing 'pop-up' prisons. It's not April Fool's Day yet Kel #FalseNews."
Ms Collins actually suggested them in 2009, but called them "pre-fabricated modular accommodation units".
This month Corrections put out a tender for three such units of 126 beds, each on existing prison grounds - two at Rolleston and one at Tongariro.
"The budget is probably going to run into the tens of millions," says Corrections chief custodial officer Neil Beales.
"Got to wait to see what the market brings."
Mr Beales says inmate numbers are climbing far quicker than expected.
"It's a little bit like having a bathtub," he says.
"We may not be able to close of the tap but we need to be able to build a bigger tub."
New Zealand's prison population hit 10,000 last year, and Rimutaka Prison has been using fast-build units since 2011.
"It's not a crisis; we are very used to dealing with population pressures. The ebb and the flow, this is part of what we do," Mr Beales says.
But Mr Davis says we are locking too many people up and not solving the bigger problem of crime.
"New Zealanders are not safer because we're building more prisons. In fact one of the conversations I had here today with a prisoner was gangs love it. They're just recruiting grounds, and the bigger the prisons get the bigger the gangs get," he warns.
Corrections Minister Louise Upston says with the prison muster at a record high, it's prudent for Corrections to explore ways to increase capacity within a short timeframe.
Newshub.
