Geobind founder Doug Sturrock of Kerikeri has created a "hemp-binder" which is being dubbed a game-changer for New Zealand's hemp construction industry.
Geobind founder Doug Sturrock of Kerikeri has created a "hemp-binder" which is being dubbed a game-changer for New Zealand's hemp construction industry.
A Kerikeri builder is set to release the country’s first New Zealand-manufactured hemp-binder to the market.
Rockstead Construction owner Doug Sturrock’s new invention, Geobind, is being labelled a “game-changer” for New Zealand’s newly emerging hemp construction industry.
Geobind is a bio aggregate concrete-like product made out of New Zealand-sourced minerals and hemp fibre used to build Hempcrete houses.
Industry experts are calling Geobind the “missing link” of the country’s hemp construction industry ecology, with people now able to source all hempcrete building materials in New Zealand as opposed to importing from abroad.
“I’m very excited about the release of Geobind because it has huge potential to change construction in this country for so many reasons,” Hemp Building Association Australia and New Zealand (HBAANZ) co-founder Jo Say said.
“There are a lot of moving parts currently in this industry, so getting the binder is the linchpin for the whole ecology and I really support and believe in what Doug is doing.”
The use of Hempcrete has been widely embraced in Europe, America and Australia for many years, yet its uptake in New Zealand has been slow due to a lack of available materials.
Hempcrete is a building material made from “hemp hurd” (the inner stalk of the hemp plant, sometimes called “shiv”) which historically used a lime-based binder and water to “cement” the material together.
Buildings made out of hemp are usually constructed with a frame, with the walls then infilled with the hemp hurd.
From there a chemical reaction occurs between the water, lime and hemp, which essentially petrifies the material and turns the lime back into stone.
This creates a strong, earthquake-proof and fireproof material, which is also resistant to mould, with the potential to last for hundreds of years.
Sturrock said he believed with the recent establishment of a decortication plant (hemp fibre processing factory) in Christchurch and the upcoming release of Geobind, the interest in hempcrete would increase.
“Hopefully now with the available products, building a Hempcrete house will start to become a normal process,” Sturrock said.
“People in the housing and construction industry are looking to reach their net-zero goals by 2030, so Hempcrete can be used to apply to both commercial and residential construction to mitigate carbon.
“That’s why I push this product because it has so many layers - it’s sustainable, it produces net-zero-carbon buildings, it helps buffer moisture and prevent mould, and is high-performing. It’s a game-changer.”
Sturrock said he first started thinking about hempcrete during the early days of Covid-19 when searching for ways to diversify and make his construction business, Rockstead Construction, more sustainable.
After failing to find a hemp binder produced in New Zealand, Sturrock decided to come up with his own.
From there he pitched his idea to Northland Inc’s Regional Business Partner Network and later Callaghan Innovation, who recognised the potential of his product.
“Callaghan was able to provide me with the business and thorough research and development support needed for my product,” Sturrock said.
“We currently have $250,000 in the project, with Callaghan structuring their funding with a 60/40 split and my business taking on the larger share.”
Andrea Primrose-Netzler is Northland Inc’s Growth Advisor/Callaghan Innovation Customer Navigator and worked with Sturrock to get the Geobind concept off the ground.
She said Sturrock’s story brought together many elements for success and the launch of Geobind was a testament to his work.
“Doug’s industry experience, combined with raw passion in developing a hempcrete product (and) ... ability to co-fund the research and development process has resulted in his progress to date,” Primrose-Netzler said.
Northland Inc’s growth adviser/Callaghan Innovation customer navigator Andrea Primrose-Netzler with Doug Sturrock, who she helped in getting the Geobind concept off the ground.
“It was obvious Doug had motivation to grow his business and was proactive in seeking support throughout the process to ensure his applications for funding through Callaghan Innovation were successful.”
According to the New Zealand Hemp Industries Association (NZHIA), hemp grows to maturity in 100 days and can provide three to 10 times the return of other common land uses in New Zealand.
Hemp cultivation has also been documented as being able to lift heavy metals from polluted soil.
According to Hemp Building Association Australia and New Zealand (HBAANZ), New Zealand’s built environment is responsible for 20 per cent of the country’s carbon footprint and 39 per cent of emissions worldwide.
HBAANZ co-founder Say said Hempcrete had the capacity to mitigate not only the climate crisis but a range of health and safety issues associated with cold, damp homes.
“A Hempcrete house is essentially a carbon sink, so absorbs tonnes of carbon out of the atmosphere, rather than generating or putting it back into the atmosphere, like traditional homes do,” Say said.
“Hempcrete is also one of the very few materials that has the capacity to self-regulate moisture in a building, which means you always have a stable internal temperature and virtually zero heating or cooling is required.
“We have a massive problem with housing in this country, with more than one in five homes found to be damp some or all of the time.
“As a result, we have one of the highest rates of bronchitis and asthma in the world, which costs our country around $8 billion each year.”
Mangōnui’s Toby Ricketts agreed the regulated temperature and mould-resistant aspect of Hempcrete was a key selling point when considering what material to use to build his home.
Ricketts was the first person in the Northland/Auckland region to build a fully-consented Hempcrete house and said he and his wife first found out about it in their search for more sustainable ways of building.
Due to a lack of available resources in New Zealand at the time, Ricketts said the importation of the Hempcrete building materials had made it complicated to gain building consent.
Mangonui voiceover artist Toby Ricketts' home was the first consented Hempcrete house in the Northland/Auckland regions.
The voiceover artist said he believed once there were set standards for Geobind and Hempcrete materials in the building system, there’d be a huge advance in that space.
“In 2019 we started to build our hempcrete house, but because there was no precedent for this type of build, we had to work closely with the Far North District Council to get it over the line,” Ricketts said.
“Thankfully they were really open-minded and it all worked out which we’re really thrilled about.”
Ricketts said the cost of his house was about the same as a traditional brick house.
With all of the advantages, Ricketts said he believed Hempcrete had the potential to help solve New Zealand’s housing crisis.
“I think Hempcrete could be really beneficial for everyone, particularly for marae and iwi to create papakainga due to the resources they have in terms of workforce and community,” Ricketts said.
“Māori can also grow their own hemp crops on their whenua which is far more sustainable than growing a crop of pine trees, which takes around 30 years to grow as opposed to just four months.”
Hemp in New Zealand is classified taxonomically as Cannabis sativa, with hemp cultivation regulated by the Ministry of Health.
Anyone wanting to work with cultivated hemp must first obtain the required licences from the Ministry of Health and can only sow seed varieties on the approved cultivar list.
Sturrock said he was currently taking pre-sale orders for Geobind and already had seven houses booked for 2023.
He said he was working with Carfields to come up with a hemp hurd process for an all-in-one product to be used by anyone with an NZ Building Codemark Certificate.
“We will also be getting our Building Research Association of New Zealand (BRANZ) appraisals in 2023.”
