Sustainable, healthy and safe design - building the future with wood
It is well documented that here in Aotearoa we are facing a housing crisis and the New Zealand government is looking to developers and those who work in the built environment to provide affordable answers. This has led to an increase in urban density in our main cities, with a focus on building good quality, well designed apartment blocks; something that traditionally has not been prevalent across NZ.
Traditional construction for these 4-5 storey mid-rise apartment blocks has shied away from using light-weight timber frames. This is despite their prolific use overseas, including on affordable mid-rise apartments and social housing units. Yet the benefits of using timber construction are potentially huge. Not only is the environmental impact lower, they can be faster to build, seismically resilient, and they also provide a healthier environment to live in.
For a future where sustainability is not only desirable, but is essential, engineered timber allows new heights to be reached without compromising performance. Apart from the environmental benefits, the advantages of timber construction are undeniable. Our team have worked on several successful timber projects which have all helped to save money, save time, and save the environment.
In the projects we have worked on, we have found that our clients are motivated to use timber, in the main, due to its lower embodied carbon, speed of construction and lower costs. As an example of this we recently provided an analysis for a client in the middle of constructing a traditional, five-storey steel braced-frame apartment block. We calculated they could have saved about 10-12 per cent on the super-structure, had they gone with timber, and cut out about 30 per cent of the piles, given the reduction in weight. These savings would be on top of those from reduced construction time and reduced labour demands.
While timber is not being as widely used in NZ as perhaps it should, more developers are looking into it as a viable option.
A great example of where the team brought their expertise in timber construction together was through our collaboration with Toa Architects on the Mahitahi Kainga Trust Community Housing project.
The Mahitahi Kainga Trust’s main aim in the project was to guide the design and anchor it in Te Ao Māori. From this discovery and consultation phase, a more innovative path was chosen, and the primary structure of the apartment units consisted of Cross Laminated Timber (CLT) walls and mid-floors, a far more sustainable material to concrete.
The all-important communal building consisted of a lightweight roof, concrete pre-cast walls and columns on three sides with a fully glazed front wall. The internal mezzanine floor consisted of CLT floor and walls.
Timber was chosen because the Mahitahi Kainga Trust understood it fitted with their ultimate community goals, being a more sustainable material to concrete. They also chose timber as it sped up the construction program and created a lighter building, thereby reducing foundation requirements, both providing significant cost savings to the project.
The Mahitahi Kainga Trust Community Housing project is just one example of how our team’s innovative approach and expertise in designing with lightweight timber solutions has improved the cost efficiency and constructability for low-rise construction. It is also a demonstration of how we worked with multiple stakeholders in a collaborative way, as alongside the Mahitahi Kainga Trust and Toa Architects, the project also involved 22Degrees, Bentley, LEP Construction and of course the community.
We understand that for savings on a scale that could ultimately save home-buyers significant money, you need to look at traditional light timber frames – of the kind we use for houses, which can go to about five storeys. These frames are a plantation timber, a renewable resource that captures carbon dioxide as it grows.
These mid-rise timber buildings have had no trouble meeting more stringent noise regulations overseas. Timber buildings are also light and flexible, two qualities that reduce “seismic load”, allowing them to move with the earthquake better and limit damage.
In short, the innovation of using timber construction across Aotearoa is one that can help us start to solve the housing crisis, whilst also delivering on our environmental promises. It is worth re-iterating that timber is lightweight, and provides reduced superstructure and foundation requirements, is flexible, resilient, aesthetically pleasing with proven health and wellbeing benefits, easily modified, and can be prefabricated to provide significant construction programme savings.
Through collaboration, we have the expertise to help you capitalise on these significant construction benefits.
Senior Technical Director
M: + 64 211902254