Developing a future focussed approach to building

Alternative building materials are rising in popularity around the globe, as climate change regulation requires the construction industry to evolve. A New Zealand-made Hempcrete product developed by Doug Sturrock, with the support of Callaghan Innovation, takes a future focussed approach to building, creating benefits for the industry, customers and the environment alike.

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Doug Sturrock with Northland Inc Growth Advisor Andrea Primrose-Netzler


When COVID-19 impacted Doug Sturrock’s Kerikeri construction business, he used the additional time he had on his hands to plan for future impacts on the New Zealand construction industry. Recognising the drastic changes that the industry would be required to make under the New Zealand Emissions Trading Scheme, Doug began researching alternative building materials to help offset greenhouse gas emissions in the building process.  

I was asking myself “how can I change my company to be more sustainable?”, so I started looking into alternative building materials such as strawbale and mudbrick. I came across Hempcrete being successfully used in the United Kingdom. It was carbon negative, which is unheard of, but it’s also great for the living environment for customers because it’s breathable and takes moisture out of the air, helping to combat mouldy, damp homes. My first thought was “where can I get my hands on this, I want to build my own home out of it!” ~ Doug

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Doug shows the hemp core used as part of his product.

During my research into Hempcrete and its potential use as a building material in New Zealand, I was able to connect in with existing hemp growers and manufacturers operating in New Zealand. Carfields in Christchurch were already growing 1,000 hectares of hemp a year across 100 farms, and had teamed up with Hempfarm NZ to invest in machinery to process hemp. This meant that they were able to harvest the hemp, take the fibre off it, and use that fibre for geotextiles. Hempcrete uses the leftover hemp core, a bi-product of this process, so there was immediate alignment between the work Carfields were doing and the Hempcrete product I wanted to create.  

The other part of the Hempcrete system is the binder to bind the hemp material together. All Hempcrete builds in New Zealand to date have been built using binder which is imported from overseas, which isn’t optimal when trying to reduce carbon footprint. I had assumed I would also need to follow the same path if I was to develop a Hempcrete product for use in New Zealand.  

My original outreach to Northland Inc was around accessing Regional Business Partner funding to support my construction business. The Northland Inc Growth Advisors visited me to discuss my options, and during the session I mentioned my idea to develop a Hempcrete product. They were able to connect me in with Callaghan Innovation to help me assess the feasibility of my idea, and push it through research and development.  

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A wall constructed using the Geobind product.

Initially we undertook a Literature Review, fact checking available information to confirm what Hempcrete products and material were currently available overseas. We also did preliminary testing of binders imported from overseas, to ascertain what the benchmark was for performance of existing products.  

I was then awarded a Project Grant through Callaghan Innovation which allowed me to undertake further testing to develop and refine a bespoke binder. We’re now at a point where we’re awaiting results which will provide refined ingredient ratios to create a NZ-made binder which is similar to overseas mixes, refined to perform in the New Zealand environment. Through the R&D process we’ve actually discovered a second binder mix, which utilises NZ minerals and is outperforming the original formulation. 

As a builder who hasn’t worked in the product development space before, the R&D process was very daunting to start with. Callaghan Innovation provided me with a lot of connections and networking, which were a huge help as that helped me navigate the process. Through Callaghan Innovation funding I’ve been able to undertake research and testing to develop and refine a market-ready hempcrete product, Geobind, for New Zealand. ~ Doug  

Looking ahead, I’m working on the development of the platform to launch and sell Geobind. Additional testing will provide credentials to confirm the safety and performance of the product, ahead of the official product launch.