Aesthetics, legalities and the promise of carbon-neutrality

This article was written by BY Nicky Lobo released on August 9th, 2024 on Indesign. Part 1. Part 2.

The age of hemp? Aesthetics, legalities and the promise of carbon-neutrality

…why the material hasn’t been used more widely….

Nicky Lobo

Gold star for green credentials

One of the fastest-growing plants on earth, hemp was recognised early on for its versatility, and today is found in industrial and commercial products including textiles, paper, biofuel, food and building materials including paint and insulation – and is used as a structural and decorative finish. 

Its basic physical properties are impressive. It grows up to six metres in a matter of months and is almost six times stronger than steel. But it is particularly relevant to the contemporary architecture, design and construction industries because of its remarkable carbon credentials: it is one of the few materials we can call carbon-neutral, because it absorbs more carbon than it emits throughout its growth cycle. It’s also a ‘nose-to-tail’ resource, with everything from its seeds, oils and fibres used in a productive way, with little to no waste. 

A resource with a rap sheet

Hemp has historically suffered from negative conceptual and, ultimately, legal association with the cannabis plant, from which it is virtually indistinguishable to the naked eye. “It only became legal in 2008 for growing, and in 2017 for eating [by humans in Australia],” says hemp advocate and building designer, Jeremy Thomas of Environmentarian. “So these two factors mean hemp is now not just legalised, but they also help with the de-stigmatising and redefining of the hemp narrative.”

A question of aesthetics

As a natural material, hemp displays some very particular physical characteristics, which can be polarising and inappropriate for some architectural settings. 

“We were looking at the hemp work that was being produced, and it didn’t really talk to us as architects,” explains Anna Maskiell of Public Realm Lab, who have recently completed the award-winning adaptive reuse of Mildura Powerhouse, which features hemp construction. “So, we were curious to ask: how do we lean into this kind of biogenic material that we really believe is the future and develop a new architectural language that responds to its properties?”

Phoebe Settle of Woods Bagot, who’s been working on Australia’s biggest hemp project to date at the University of Tasmania, agrees: “I think it may always be slightly niche in terms of its use, especially at a non-domestic scale, because of its particular appearance. It’s a very raw, natural aesthetic so that doesn’t suit every environment. Also, there are parameters around the thickness and there are only certain spaces that can take that kind of depth.”

The downside of youth

Being an immature industry, hemp procurement can still be a challenge to navigate, dependent on and vulnerable to unpredictable agricultural growth cycles. “At the moment, there’s a bit of a glut of unprocessed hemp in Australia,” says Dick Clarke of Envirotecture, who have been designing hemp homes in NSW for more than 12 years. “But three years ago, we were importing it [due to the drought],” he recalls. Along with challenges of availability, as a naturally grown material, there are also inconsistencies in character and quality to contend with – which can be a barrier for larger commercial projects. 

Similarly, due to the newness of the industry, there is a skills shortage in hemp construction techniques – particularly for projects at scale. “There are people who do it, but those people are typically very small businesses, like one or two people, and have done it on a much smaller scale,” explains Alastair Flynn, Associate Principal at Woods Bagot. With demand, however, this is shifting.

“We just need to make the revolution irresistible”: A story about hemp

…hemp in today’s built environment, we consider risk and reward.

Nicky Lobo

This article was written by BY Nicky Lobo released on August 22nd, 2024 on Indesign. Part 1. Part 2.

Regulation hoop-jumping

While hemp has recently been included in the BASIX system used in NSW, the National Construction Code for non-residential building does not recognise hemp as a standard material. Nor does it allow for expert opinion as a means of satisfying the performance requirements in Volume 1 for non-residential buildings. Instead, it requires rigorous, specific and costly physical testing or code-marking in a certified laboratory to demonstrate performance with fire and weatherproofing requirements, for example. This is all logical and understandable – we need to know our buildings are safe and have longevity built in – but this process can add up to $100k to a commercial project. That’s clearly prohibitive in many cases, and stifles innovation from all but the largest materials manufacturers.

All this means that larger commercial hemp projects require a significant amount of ideological, and financial, buy-in from the client. “A small business wouldn’t be able to get that done,” comments Alastair Flynn, Associate Principal at Woods Bagot. “Many clients couldn’t [carry the risk and cost], or they wouldn’t see the value in it.”

High reward

All this makes it difficult for hemp to scale up to commercial-grade buildings, but with Mildura Powerhouse a success and University of Tasmania set to add to the precedent case studies, the hemp wave may have begun. 

“Luckily for us, Anna [Maskiell] actually kicked the door down before we did in time because [her] project was running about a year and a half ahead of ours,” shares Dick about Envirotecture’s 560-square metre multi-function Women’s Shed in Lithgow currently under construction, which also uses hemp for all its external walls. “We were able to actually use some of the material that she had put together, and the fact that the certifier in Victoria had accepted it I think had an influence on the certifier we were dealing with in New South Wales,” he continues.

Samples of Otteto’s signature Living Canvas Wall System.

The growing hemp wave

‘There is very little resistance and a great amount of enthusiasm for hemp,’ says Clarke. ‘Most architects and designers I’ve come across have a will and a basic, if not detailed, understanding of the carbon debt that conventional buildings incur and the need for high performance in operation.’

Maskiell is similarly hopeful: ‘It feels like it could be a significant shift, and it’s building momentum, but it also feels very vulnerable at the same time. So it’s incredibly exciting but it also needs careful, considered advocacy and delivery.’ Using precedents and harnessing the growing knowledge and willpower of the collective, the Australian Hemp Council has brought together a task force to actively mainstream hemp’s use in design and construction via strategic campaigns to adjust regulatory systems such as the Australian Standards and building codes.

A lot of work is needed; however, the passion of the hemp advocates is unwavering, whilst their experience and expertise grow, and case studies mount. At this early stage, collaboration is clearly critical. “There was no single party that could have pulled this off without collaboration with others, so you’ve just got to get your heads together. If you think you have the right client and the right contractor, you can achieve this kind of innovation,” says Flynn.

Along with Mildura Powerhouse, the University of Tasmania buildings will be accessible to the public – achieving the kind of exposure that could also influence the material’s trajectory. “The nice thing about this project is people will walk off the street into the space and actually see it,” Flynn continues. “It will be really good for people to experience.”

Every project and every individually financed certification and test help to unlock the potential of this remarkable material. With more and more hemp products on the market, the tide looks set to turn. “Now we’re working with every other hemp product we can get our hands on that is appropriate, with the relevant requirements for the project we’re doing,” says Anna. “So, we’re using prefabricated hemp block, and looking at prefabricated panels.

“We just need to make the revolution irresistible.”

This article was written by BY Nicky Lobo released on August 9th, 2024 on Indesign. Part 1. Part 2.