Home sweet (hemp) home

December 5 is UN World Soil Day. The building industry has thus been called to account for its role in the massive use of mineral raw materials and environmental pollution. One solution comes from the bio-construction sector which draws on unlimited sources of natural materials such as hemp, which is a recyclable carbon sequestrator. But how comfortable is it to live in a hemp house?

Building with wood, straw, and hemp. Biobased materials are seeing ever more use in the construction sector, which needs to become more sustainable as it is one of the major sources of soil, air and water pollution.

Forty percent of global raw material is consumed by the building industry. Fifty percent of CO2 emissions into the atmosphere come from the construction sector,” reports Italian bio-construction expert Paolo Ronchetti. Moreover, “Traditional building and insulation materials – of mineral or synthetic origin – are rarely recyclable. At the end of their life they are disposed of in landfills. Therefore, besides having an important environmental impact for their production, they have an equivalent environmental impact for their disposal.”

Biodegradable and from unlimited sources. Instead of exploiting the earth’s crust, and using a process that consumes energy and pollute, the bioconstruction sector can get its materials from the field. Hemp is one of the best examples; it can be grown in crop rotation and improves the quality of the soil. The plant is also a “carbon sequestrator”: it grows very quickly and acts as a carbon store, absorbing atmospheric CO2 for as long as it continues to exist.

Ronchetti adds: “You should consider that one cubic metre of a brick made from hempcrete – a hemp and lime biocomposite – instead of emitting C02, and polluting, it captures 20 kg of CO2 from the atmosphere. A cubic metre of low-density hempcrete biocomposite, which is sprayed to insulate roofs or subfloors, can remove 60 kg of CO2 from the atmosphere. So you can imagine – with the volumes and the numbers in the construction industry – how much this virtuous model of building with hemp and lime can fight climate change.”

To note, in the past, industrial hemp was banned in many countries because it was associated with illegal marijuana, from which it differs as the psychoactive compound ‘THC’ is present in proportions of below 0.2%. A thriving industry was consequently stopped. Now hemp farming is flourishing again.

This material also has other advantages. It allows builders to make high-performance envelopes and offers more comfortable, healthy and energy-efficient houses. Furthermore, the traditional building industry has increasingly used synthetic and chemical products that can be toxic and hazardous to human health. Tough low allergen design using natural materials is becoming a new trend.

Northern Italy, Chiari, near Brescia. “In the Po Valley summers are terribly hot and humid. Winters are cold and damp. Humidity rules here!’’ says Sara Bordiga. His husband, Mauro Cogi, longed for an eco-friendly home, and started studying all the available possibilities on the market. Finally, he opted for hemp and in 2015, Mauro and Sara moved into their new biobased house with their child.

“My husband’s choice really surprised me. I had never heard about hemp houses!” says Sara.

Mauro, an engineer, personally followed all the building phases. “The hemp technology works very well. I wrapped the whole structure in this monobloc hemp envelope, thus avoiding thermal bridges.” It’s monobloc because they didn’t use bricks, the hempcrete was sprayed directly onto the structural walls.

As this natural material is porous, it allows the building to “breathe”, avoiding any stagnant humidity. It also keeps a consistent temperature, thus cutting heating and cooling costs.

“Unlike what happens in homes with traditional polystyrene cladding, which doesn’t let moisture out, hemp allows good air exchange. This leads to very dry walls and high environmental comfort,” explains Mauro. “In this house, whose heating and cooling systems are only electric, the maximum power required is 1.8 kW, which is little more than a hair dryer. And with this 1.8 kW I can cool or heat 180 square metres.”

“Zero mould. Zero moisture,” confirms Sara. “And we’re doing well! There is a good level of comfort, we live well in terms of air and well-being.”

Hemp mixed with lime is the usual solution to insulate this kind of building. But European researchers, working on the project called Isobio, went further and developed a lighter but more rigid panel, with improved thermal conductivity. Thanks to innovative biobased binders, whose formula is still a secret, there’s no need for lime. This solution has breakthrough potential in the building sector.

Mike Lawrence, professor at BRE Centre for Innovative Construction Materials, University of Bath, UK, explains: “This material is the major innovation. It is a mixture of the hemp shiv – the woody part of the hemp stock – and it’s been mixed with the thermal setting binder which is also biobased, to make something which is rigid but strong… Much much stronger than you will get with hemp lime, which is much more brittle material. And it’s a lower density than hemp lime, and it’s much more flexible in the possibilities.’’

“The other innovation is a low density, a low thermal conductivity render, and that’s made up with also hemp shiv but it’s very fine. And this is mixed with lime. But because it’s so fine and because of the formulation of the lime, you end up with a render which is very high performance, very low thermal conductivity, much much better than a normal lime render. It’s laid in two layers, it’s got a reinforcement, it’s a sort of plastic grid which is put in between the two layers just to stop it cracking. And on the top – when you put these layers on – you put a standard lime plaster, a lime render which provides the resistance, the full resistance to the weather. Because hemp has the ability to absorb and desorb humidity, on the outside when it’s raining you don’t want that, so you put this out of surface, which will stop the water coming in,” he adds.

“Between the panels we put a fibre insulation. This insulation is made up primarily of recycled cotton, and it’s also got fibres from flax and from hemp,’’ Lawrence concludes.

The researchers are testing these and other innovations in different climates, in Spain and in the UK. They installed their composite panels in two demonstration buildings in Seville and in Wroughton, and now they are monitoring applied solutions. According to their results, they can achieve 20% better insulation performance than conventional materials, 50% less embodied energy and CO2 emissions, 15% reduction in total costs.

Oliver Style, energy consultant and researcher for Isobio says: ‘’I think that the real innovation is bringing together biobased materials, a lot of which have been used in traditional constructions for centuries, and applying modern solutions to make them fire-resistant, water resistant, to make them bind well and combining all of these different materials in a prefabricated wall system, which can be industrialised. I think up to now a lot of biobased construction has been very small scale, it’s been in the field of people who are very committed to biobased buildings, but it’s quite small scale, quite bespoke. So what we’re trying to do is create scalable solutions that can be built at industrial scale and which can make all of the requirements of the marketplace regarding thermal performance, fire performance, resistant to different weather conditions.’’

The composite panels should enter the market by the end of the decade. These biobased materials are expected to become ever more competitive in the next years, as the European Union requires all new buildings to be “nearly zero-energy”, which means very high energy performance, by the end of 2020.

By Loredana Pianta

27 November 2018

Journalists can download the video teaser and the BROLL [11’, original sound] in HD quality and scripts, free of rights and charge, here: mediacenter.youris.com

What about GMOs in our homes?

Adopting biobased materials in home building can slash construction costs, but is Europe ready to put aside its fears about GM products?

One of the main contributors of CO2 emissions are the homes we live in. In the EU, buildings are responsible for 36% of CO2 emissions and 40% of energy consumption.

Researchers argue that, compared with using traditional mineral-based materials in construction, “eco-friendly” durable composites can slash by half the embodied energy and improve insulation by 20%. This means better efficiency but also reduced building costs. The hitch, though, is what biobased materials to use. And is it advisable to avoid GM products?

GMOs, genetically modified organisms, are among one of the most controversial topics in agriculture. Experts have divergent views. “The current EU GM regulation is very much outdated and dysfunctional. Plant science has in the last 15 years made enormous progress,” says Stefan Jansson, professor in the Department of Plant Physiology at Umea University, Sweden. “Gene transfer from GM crops to wild relatives is no more or no less risky that gene transfer from all other (domesticated) crops to wild relatives, which no-one ever cared about.”

It is important to ask why we are shying away from GMO products, argues Jonathan Jones, a professor at The Sainsbury Laboratory, UK, working on a project to test modified potatoes and their resistance to blight. “The GM method is totally benign and totally safe and it enables you to move genes that do different things from one plant to another,” he says.

However, some groups pioneering the use of natural products in construction have opted to avoid GM materials.

It is the case of the European project ISOBIO, which is developing innovative solutions to boost the use of bio-based materials in construction. They do not use agricultural waste from GMO plants.

Moreover, the companies that joined the consortium source local products, which will be easier to recycle being part of their landscape. Manfred Lemke, from Claytec, a Germany-based developer and producer of clay, points out that they take their straw from the fields around the factory. “Cavac, another partner in the project, sources hemp from local farmers near its base France, rather than importing materials from overseas. ‘Think global act local’ for supply chains, it avoids contamination and further risks of anonymous, global supply chains,” he adds.

“Recycling agricultural waste sounds like a positive aim. If GM crops were involved, then the potential harms would need to be thoroughly, and independently, examined,” argues Liz O’Neill, director of campaign group GM Freeze. “Even the tiniest change to the genome can have unexpected impacts, both within the organism itself and in the ecosystem into which it is introduced, ” she says. According to O’Neill, EU labelling laws help consumers identify products with GM ingredients and avoid them if they wish.

In this context, EU Ecolabel, a voluntary labelling scheme, certifies, among other things that products do not originate from genetically modified organisms.

However we approach the GM issue, looking forward to further research on it, it is certainly important to brand any products containing GMOs to allow consumers to make their own decision.

 

By Sam Edwards

Photo credits: Redd Angelo

4 October 2017

Save the date! Next ISOBIO stakeholder workshop, 21 November in Madrid

ISOBIO partners are pleased to announce that the 4th stakeholder workshop will take place on 21 November (afternoon), at the Acciona offices in Madrid (Alcobendas).

With the project now moving towards the demonstration phase, the workshop will be the perfect occasion to present the innovative bio-based solutions which industrial partners have been developing during the project. Other European projects will also show their own cutting edge eco-materials at the event.

The workshop will be of interest to professionals within the construction industry looking to keep abreast of the latest developments in the field of sustainable construction materials.

More information, including the agenda and registration details will be available soon.

Bio-based materials facing the challenges of the construction industry

The use of bio-based materials is often met with scepticism from architects, insurers and contractors in the construction industry, which has led to slow market uptake. This scepticism generally results from a lack of adequate training and support with regard to regulatory frameworks.

This was the backdrop of the ISOBIO workshop, held 22 March in Brussels where the project team met with representatives from Earth Building UK and Ireland, BC architects & studies, the ECO-SEE project and the German Association for Building with Earth. The aim was to identify the levers for faster adoption of bio-based material in the construction sector.

The workshop was able to pinpoint new ways to improve professional knowledge, develop adequate curricula and set out a suitable legal framework. A further issue to be addressed going forward is how the general public perceive the emerging bio-based construction sector in comparison to the established construction sector.

Drawing on its early achievements, ISOBIO gave valuable insights into its testing and prototyping activities with a view to raising awareness and encouraging greater acceptance of bio-based materials. The project partners reiterated their common goal of designing a bio-based product which offers high insulation, low embodied energy and carbon, and hydrothermal efficiency for a greener building and construction industry.

A key finding from the workshop was that standard products (panels) made from enhanced bio-based properties could possibly be a leading driver of market uptake for bio-based materials in the industry.

The workshop report is available here.

To download the presentations, click here 

29 March 2017

On the way to demonstrating the benefits of bio-based materials for the construction sector

ISOBIO aims to develop new bio-based insulation panels and renders, and to scale them for mainstream adoption by the building and construction industry. The focus is now on the challenging demonstration phase.

ISOBIO innovation partners are bonded by a unique goal: to design a bio-based insulation material with the right chemical and mechanical properties to tackle water absorption, fire resistance and moisture buffering while ensuring high thermal conductivity. These essential properties provide material resistance as well as indoor wellbeing and confort.

In February 2017, partners convened on the premises of TWI in Cambridge for their mid-term project meeting. It was an opportunity for them to assess the research and preliminary prototyping, and to outline the regulatory and market challenges ahead. Following this meeting, the final composition of the bio-materials is now just around the corner.

As part of their research, the Universities of Bath and Rennes have examined the characterisation of bio-materials and the development of composite materials (including the insulating core and the composition of the external layer). These research results form the basis for the technical developments by industrial partners Cavac, BCB and Claytec. The innovation lies in the feeding of knowledge from the labs into the industrialisation phrase.

After testing and prototyping, ISOBIO is poised to reveal a bio-based product design offering all the right properties for a greener building and construction industry: high insulation, low embodied energy and carbon, and hydrothermal efficiency.

 

17 March 2017

When indoor air is more polluted than outdoor air

“Besides the contaminants we find outside, we also have indoor contaminants. There are pollutants typical of homes such as dust, spores, moulds, and those produced by human activities like cooking and house-cleaning, that contribute to the release of additional damaging substances,” expert warns

Indoor air pollution kills 4.3 million people globally every year, according to the World Health Organization (WHO). The main causes are heating and cooking practices that produce high levels of toxic substances, such as fine particles and carbon monoxide.

Prof. Alessandro Miani
Prof. Alessandro Miani

Doctor Alessandro Miani, heads-up the non-profit Italian Society for Environmental Medicine (SIMA), which recently drew up a set of rules to preserve the air we breathe in our homes and offices. Miani, who is also professor of hygiene and environmental prevention at the University of Milan, discusses environmental medicine and the need for public health strategies to tackle indoor air pollution.

Professor Miani, the last WHO report shows that indoor air may be more harmful to health than outdoor air. Can you explain how this happens?
Indoor air is basically the same as outdoor air, but the difference lies in the amounts and types of contaminants. Indeed, besides the contaminants we find outside, we also have indoor contaminants. There are pollutants typical of homes such as dust, spores, moulds, and those produced by human activities like cooking and house-cleaning, which contribute to the release of additional damaging substances.

What’s the aim of the rules laid out in the SIMA Indoor Air Quality document?
In Italy, while for outdoor air there are laws that regulate the subject matter, there is no comprehensive set of rules that govern indoor pollution. Of course individual citizens should also convincingly adopt their own virtuous behaviours because the environment does not belong to states and governments, but to each one of us.

 

One way to improve indoor air quality is using biobased construction materials. For example, the European Isobio project is studying natural materials, like hemp and straw. By “breathing”, they offer better ventilation and help reduce damp. What benefits could this field of research provide?
There are no doubts that bioarchitecture and bioconstructions can contribute to improving the overall well-being of those who spend a lot of time indoors, and can offer practical help to improving the energy efficiency of buildings.

All this has a positive effect on the amount of harmful emissions from the heating systems of our homes, which are the biggest source of thin particulates in large towns. Moreover, there are many other entrepreneurial initiatives that, thanks to new compounds, are seeking to improve air quality. New green roof tiles and a new antismog paint are some examples.

 

What is meant by environmental medicine?
Environmental medicine deals with prevention, diagnosis and treatment of disorders that may be related to “environmental factors”. This is a sector that encompasses various disciplines such as biomedical sciences, environmental sciences, legal sciences, economic science, social and political science, material sciences, and construction science.

Environmental medicine may be considered to be the medical branch of the much broader field of environmental health, which, in turn, is a part of public health. It is not very well known in Italy, but it has been explored by WHO and is a common concern in the US.

 

Even though it is a fundamental issue for our health, it seems there is not enough attention to environmental medicine in the media of your country, Italy. Are there sensitivities around these issues?
The media need information that has been verified and certified, and this type of information can be provided only by associations and bodies that have strong ties with research and science. Releasing information through the media about initiatives aimed at informing the people or that intend to be a stimulus for politicians and institutions, requires players who are credible and well-known.

So I don’t think it is about hurting “sensitivities” but rather about the fact that so far the few people who have dealt with this issue before us, have restricted themselves to a specialised medical approach. Environmental medicine is instead a multidisciplinary field, aimed at preserving human health and at avoiding that our surroundings may become an environmental factor that causes diseases, injuries and premature death.

 

By Elena Veronelli

Photo credits: Joshua Ness

23 January 2017