Daiman Otto, Design and Digital Construction Director of the innovative design and technology-led company Tallwood, believes a combination of digital design and offsite manufacture may be the solution to New Zealand’s housing issues.
New Zealand’s building industry is failing to meet the demand for housing, and the prospect of securing an affordable home is becoming increasingly remote for many Kiwis, particularly in Auckland. The government is cracking the whip in response to the issue, with initiatives such as Kiwibuild and the establishment of an Affordable Housing Authority, however these initiatives will be effective only insofar as the current building industry’s capacity will allow.
Against the backdrop of a supply and affordability ‘crisis’, leaky homes and substandard builds, what would stepping outside of the box look like for New Zealand’s building industry?
“The solution lies in a shift away from traditional construction methods,” says Otto. Tallwood, which aims to be the catalyst for this change, is itself the product of the merger of the businesses of Stanley Modular Limited, a leading offsite manufacturer, and Tall Wood Limited, a digital design and technology start-up.
Tallwood uses prefabricated methods of construction. Structural members, walls, floors, roofs and other key components are machined offsite in a factory and assembled into components. The components are then delivered to the site where they are installed to create a building ready for interior finishing.
Prefabrication has been slow to gain traction in New Zealand as a long-term solution. That’s partly due to preconceptions around quality and design. Many of us remember Ministry of Education classrooms or Ministry of Works site offices and associate ‘prefab’ with rudimentary, cookie cutter buildings. Otto says that that’s all in the past. Digital technology enables far greater customisation. “Prefabrication is about mass-duplication and repetition is critical to ensuring affordability, but digital technology allows for bespoke design,” says Otto. “We’ve come a long way from the nondescript, prefabricated buildings of the 20th century.”
As for ‘prefab’ being substandard relative to conventional builds, Otto says the opposite is true. “Utilising digital technology reduces scope for human error and brings precision and accuracy to the design and construction process. Plus the manufacture is carried out in a controlled environment that is not affected by the weather. The final product is a building built to very small tolerances. It’s weathertight and warm.”
Tall timber innovation
Tallwood uses the aptly named ‘tall timber’ technique to construct mid-rise buildings out of engineered timber. The walls and roofs are made from cross laminated timber (CLT), composed of multiple thin layers of timber glued together. CLT produces a strong, rigid product that performs in the same way a precast concrete panel would. Laminated veneer lumber (LVL) is made in a similar way to form posts and beams and stands in for concrete and steel structural members.
A relatively foreign concept in New Zealand, building ‘tall’ with timber has been a common method of construction in Europe and Scandinavia for over 20 years. Now, a new generation of timber towers are popping up all over the globe, and they’re reaching record heights. Notable examples include the Brock Commons Tall Wood Residence in Vancouver Canada. At 53 metres in height, the building is the tallest timber build to date. Since its completion in 2017, Japanese timber company Sumitomo Forestry has already revealed plans to build the world's tallest timber building in Tokyo. The building will be 350 metres tall, with a completion date of 2041, timed to meet the company’s 350 year anniversary. The skyscraper will be Japan’s tallest building. Closer to home, Sir Bob Jones recently announced plans to erect a 52 metre tall timber building in central Wellington.
Otto is not surprised that engineered timber is having its moment. “Timber has an intrinsic, enduring beauty and it is has great sustainability credentials”. Not only is wood a renewable resource, trees sequester carbon while they are growing which remains stored in the wood for the lifetime of the building and beyond. The processing of wood creates less pollution than traditional building materials too, and precise manufacturing techniques involved in engineered timber all but eliminates wastage typical in traditional construction methods.
Affordability, productivity and certainty
Tall timber buildings are cheaper by 9-14% compared to conventional concrete and steel builds, according to a recent study by Forest and Wood Products Australia, while PreFabNZ cites a 15% cost saving in overall construction costs for a prefabricated house of 152m². Cost savings are attributed to efficiencies gained via a number of avenues – standardisation of products and processes, building in a controlled environment, eliminating rework, cutting waste, an accelerated construction program, and less truck movements and crane time.
Otto claims Tallwood will likely achieve at least a 30% reduction in build time for a 42-apartment development they have underway at Hobsonville Point. The manufacture process can take place offsite in parallel with site preparations. The installation process itself is fast, with the building – depending on size – coming together and closed in weeks, rather than months.
“This is a fraught development environment. There are so many variables that are out of a developer’s control,” says Otto. “Working with Tallwood can reduce the number of variables and bring some certainty to the process.”
“Design, engineering, materials and logistics feed into the entire production process, all of which can be anticipated early on. This provides certainty of time, cost and quality from the outset, and the ability to manage risk, close loops and reduce cost”.
Several Tallwood-manufactured buildings are currently underway throughout the North Island. The Grounds at Hobsonville Point, a 42-apartment project, will be completed in Spring this year. In addition, Tallwood is part of an initiative to design affordable, sustainable homes which contribute to the health and wellbeing of rural Māori. In collaboration with Toi Ohomai, Unitec Institute of Technology and Scion, a Crown research institute, Tallwood will work with local iwi to research optimal designs for sustainable, affordable housing for a papakāinga or housing community. Toi Ohomai was awarded funding for the research project as part of the National Science Challenge.
While commentators and regulators continue to pose solutions within the confines of an outdated construction industry, Tallwood is advocating for radical change. Otto is hopeful that Tallwood’s model will serve as a catalyst, inspiring imitation and innovation so that high-quality, healthy, sustainable, cost-effective houses and buildings become the norm in New Zealand.