Red Stag’s first-of-a-kind CLT modular production line

The Prime Minister, Christopher Luxon, opened the Southern Hemisphere’s first off-site production line to use Cross Laminated Timber, CLT, as the structure.

The initiative is a collaboration between local industry leader Red Stag, German architecture firm NKBAK and Austria constructor Kaufmann Bausysteme. The initial launch stage is supported financially by MPI’s Primary Sector Growth Fund.

The project name, VoMo stands for ‘volumetric modular’, meaning whole room modules are completed on the production line.

“These factories are proving highly effective in Austria and Germany”, explains Red Stag group CEO Marty Verry. “They facilitate efficient installation of fit-out within the modules, using an Austrian technology backbone. The efficiency savings help cover the cost of running the factory and transporting the modules to building sites.”

“Poor labour productivity on construction sites has become a big impediment to building fast and efficiently in New Zealand, he adds. “Developers are looking for ways to compress construction times in half. CLT is an enabler to this; the strong, durable, yet lightweight engineered wood panels provide a rigid shell that can easily be transported to sites.

“Initial foundation work on site runs in parallel with work on the modules in the factory, rather than sequentially. Typically, this takes one-third to one-half out of the overall construction programme.

“The controlled factory environment also allows for less variations and contingencies, which is a big factor in developer’s feasibility models. Contingencies can reduce from 10 percent to 5 percent because what happens in the factory is totally locked down.

“The strength of CLT also means the modules can be stacked into very high building designs. Ten to twenty storeys are not out of the question, and we have worked with top local engineers to finalise module-to-module connections that also reduce any acoustic flanking.”

The facility is set to benefit sectors such as school classroom blocks, apartments, townhouses, cabins, hotels, student accommodation, offices and retirement care facilities.

“A lot of these sectors are very sensitive to construction noise, truck movements and disruption, making off-site volumetric modules an attractive option”, says Verry.

VoMo has projects secured for 150 modules over the next two years. The line will ultimately be able to produce up to 800 modules annually. In Europe, the partnering company supplies 4-5,000 modules annually from four factories.

“This is a great result for NZ-Inc too, adds Verry. “With CLT, we are substituting a sustainable locally produced material for what would otherwise be high-emission imported steel and cement.

“This is something we want politicians and bureaucrats to realise and adopt strategic procurement policy around. A dollar spent on heavy gauge steel does not come from Glenbrook or its electric arc furnace, it comes imported with high emissions. Likewise with concrete; only 60 percent coming from Golden Bay Cement and the rest imported. Any substitution with CLT therefore comes off imported cement volumes.

“On the other hand, a dollar spent on local CLT supports New Zealand businesses and jobs, reaching deep into rural New Zealand, often to iwi owned forests. It allows us to invest in greater capacity and efficiency, which in turn brings down construction costs and ensures domestic supply resilience.

“This extra scale allows New Zealand processors like us to have a better cost base to be able to compete in export markets.”

The industry is pushing three policies to achieve this:

• A Wood Option Policy (WOP) requiring an optimised wood design option taken through to the Preliminary Design stage for government projects. This ensures wood has a chance to compete and typically results in wood being selected at no additional cost. Too often wood is not considered because designers do what they find easiest for them. Most building types can be cost-equivalent in wood if the design is optimised early.
• Bringing Harvested Wood Products carbon storage into the ETS. This storage accounting is included in New Zealand’s Nationally Determined Contributions, but not yet distributed to wood processors, despite the National and Act Parties promising a scheme that would do so at the last election. A Cabinet Paper is drafted and pending.
• Embodied Carbon reporting at the Building Consent stage for larger buildings that often use high-emission materials. Many European countries, and now New South Wales has adopted this. Plug-in software such as Nezo integrates with standard building design packages to facilitates this, so it’s basically a cost-free policy. It will encourage designers to think about their material selections and their impact on this 12 percent source of global CO2 emissions.

Source & image credit: Red Stag