11th International Hemp Building Symposium

Tuesday 10th October 2023





Steve Allin, IHBA Director, Ireland and Rens Borgers, KalkHennep Nederland.

Steve Allin has enthusiastically pioneered the use of hemp in building since 1997 and wrote Building with Hemp the first book on the subject in 2005. He is now a leading expert in the field, with a wide knowledge of the growing, processing and utilisation of hemp in construction. In 2009 he founded the International Hemp Building Association and he now works as an international Hemp Building consultant, develops training courses for Hemp building techniques and travels around the world spreading the knowledge.

Rens Borgers is not only one the most experienced hemp builders in the Netherlands but he is also a founder member of the Dutch Hemp Building Association ‘KalkHennep Nederland’. His building company EcoBauSalland was responsible for the casting of the hempcrete facade we are going to visit on the 11th.



Research Session

Chaired by Liam Donohoe, IHBA Co-director, Ireland.

Liam is a building energy subject matter expert and PhD fellow specialising in building energy certification and no and low carbon product, standards and systems development. He is fluent in WUFI, iSBEM, UValuate, Therm and PHPP, also Java, Python, SQL, R, Weka, Tableau, VB and C, together with being a registered domestic and non-domestic BER Assessor, a registered Domestic Heat Pump and Solar Thermal installer, Airtightness tester and a Certified Passive House Consultant. He is also Chief Technical Officer at UK Hempcrete and a co-director of the IHBA.

Liam Donohue


MSc thesis: Hemp thermal insulation panel-Dutch context carbon footprint (FTE) & (BMO)

Rabih Hamid Wageningen University, Netherlands.

Rabih holds a MSc in Biosystems Engineering specialized in environmental footprint assessment and decarbonization strategies. Experienced Project manager (10+ years) and product development engineer specializing in circularity and bio-based materials. He is committed to driving sustainability initiatives.


Hemp supply chain, biobased construction YNE, Hemp30, CHCx3

Alex Sparrow UK Hempcrete, United Kingdom.

Alex is recognised globally as one of the leading experts in the use of hempcrete and other bio-materials in construction. He co-authored The Hempcrete Book (2014), one of only a few books on the subject and started UK Hempcrete due to the demand for his knowledge and material supply.

Alex Sparrow


Writing the Hempology Curriculum for wide ranging hemp education

Marcus Morley Jones, Ecoversity CIC, UK

A visionary and entrepreneur who has been studying the art of Industrial Design since 2018, specialising in the field of Industrial Hemp. He is co-author of the Hempology®️Curriculum, which is being designed to become an accredited multi-disciplinary qualification to educate students from grassroots to graduate level.


EIHA Working Group on Hemp Construction materials report

Francesco Mirizzi EIHA, Brussels.

Currently responsible for agriculture, bioeconomy and environmental policies at the European Industrial Hemp Association, Francesco has a 10 years long experience in working with agrofood policies in Brussels. After 2 years in the liaison office of Puglia region to the EU, he joined the Directorate General for Agriculture and Rural Development of the European Commission for a bluebook traineeship.


The Role of the Hemp Building Institute

Jacob Waddell HBI, United States.

Jacob is a past president of the US Hemp Building Association (2020 – 2022) and holds degrees in Business Administration and Materials Engineering. He is now director of the Hemp Building Institute in the U.S.


Carbon Credits and how they relate to Hemp Construction sector

Nando Knodel HempConnect -Hamburg, Germany.

Co-Founder and Managing Director at HempConnect GmbH, Circular Agriculture & Carbon Removal powered by Hemp & Pyrolysis. Member of ChangemakerXchange, a global community for young Changemakers and their social initiatives. Nando also holds a M.Sc. in Business Administration with a focus on Entrepreneurship, Finance & Corporate Governance | B.Sc. in Business Administration with a focus on Marketing.


Report on the medium term effects on hempcrete materials in a demolished test structure

Joseph Little, Technical University of Dublin, Ireland.

Through many years of architectural practice, research, lecturing and building fabric consultancy – and now through the role of academic manager – Joseph explores, promotes and teaches science-based construction practices.
Head of Construction and Building Performance in the School of Architecture, Building and Environment, TU Dublin. In that role he supports the quality and development of existing programmes, the creation of new programmes, and engages in research focused on building performance-related concerns of society and industry.


Hemp’s Sustainable Future: Insights on LCA Data Management

Jule Kaptur & Felix Drewes, Hanfingenieur Henrik Pauly®, Germany.

Jule Kaptur is a civil engineer with a Masters Degree in Resource Efficient Construction from Rottenburg University. She has worked focused on LCA for three years. Lea Stauss has designed and overseen the construction of many Hemp houses in Germany and is currently working on a thesis based on the LCA of a house she is currently building. They are both working for Hanfengineur Henrik Pauly®


Panel discussion

With the previous speakers.


Lunch at Kanteen25.

14.00 – 17.30

Demonstration of processing hemp straw with a mobile decorticator

Kristaps Eglitis

Kristaps Eglitis, who built the first prototype of the HurdMaster Micro Decorticator in his own shop, is by training an arts & crafts metal worker. The HurdMaster was inspired in part by his research of a decorticator project started years ago by Voldemars Cirulis, a Latvian developer, in the early 2000s. Kristaps is also interested in hempcrete construction and is insulating and reconstructing a family house from the material.

Demonstration of spraying hempcrete prototype structure

Damien Baumer, Ereasy, France.

The idea of spraying hempcrete onto an inflatable dome form was shared with delegates at the previous Symposium by director Steve Allin. He has had this concept brewing in his imagination for many years but with the emergence of the Ereasy system of spray application the idea seemed to got to a stage where it could be experimented with. Damien Baumer of Ereasy has taken this concept and begun to trial how to implement it with an initial test structure. We now want to enlarge the prototype to see how it works with the potential to build emergency housing.

19.00 – 21.00

Symposium Dinner at Kanteen25

Wednesday 11th October 2023



Supplying the Hemp Building Market

Max Scholtes Hempflax, Netherlands

Max Scholtes is an language expert who has worked internationally who during the pandemic became a qualified Hemp Builder and worked at L’École Nationale du Chanvre teaching the technology to a range of professionals. He now works as business Development manger France for Hempflax. He will be presenting the work HempFlax are doing to develop harvesting and processing of hemp materials.


Hemp Processing Technology in Australia’ (online presentation)

Connie Minos Ashford Hemp Industries, Australia.

With more than a decade of research, learning and development, Ashford Hemp Industries husband and wife team Leon and Connie proudly use and market their Ashford Hemp Processor (AHP) that they have designed and built in their home town.


Fast Application of Hemp Plaster

Jiri Kohler Builder, Ireland.

Originally from the Czech Republic and now based in Ireland for the last 17 years where works on mainly renovation projects Jiri has used his plastering skills to devise an improved system of applying hemp plaster.


Hempcrete projects in the Netherlands

Rens Borgers Kalkhennep, Netherlands.

Rens has been building with hemp in the Netherlands since 2010 a journey that has included a lot of learning and sharing of that knowledge. He has developed training courses and built many of the first hempcrete houses in the country.


Panel Discussion on New Technological Developments

With the previous speakers.



Developing a Hemp Based Accoustic Panel System (online presentation)

Robert Schwemmer Silent Fiber, Germany.

In 2006, he started to develop an insulation board made of HANF straw. Together with the company Capatect, the production of the natural insulating material was then established in the Weinviertel in Lower Austria. Initially to insulate facades with it. Through an exhibition in Vienna,it was found that the hemp insulation board also absorbs sound excellently. This resulted in an acoustic panel and later – the online sales platform for sustainable acoustic solutions.


Creating the market for Hemp Fibre Insulated Panels in Sweden

Remi Loren Jr Ekolution AB Sweden.

Ekolution is an innovative BuildTech company focused on the implementation and development of hemp as a bio-based building technology. We offer hemp fiber insulation and hemp lime panels that provide carbon negative, energy efficient and non-toxic buildings.

Remi Loren


‘Designing a novel hemp composite and low carbon panel system’

Chloe Donovan Natural Building Systems Ltd, UK.

The team at Natural Building Systems includes architects, engineers, material scientists and construction experts, united in a passion to design more efficient, affordable and environmentally friendly buildings. Based in the heart of East Anglia where they are developing ADEPT; a breathable, demountable and sustainable SIPs system that provides a solution for radically decarbonising the construction industry.


Hemp Building Materials for Central Europe (online presentation)

Werner Schönthaler Schönthaler, Italy.

Schönthaler have been in operation since 1964 making concrete products for the civil engineering market. From their northern position in Italy they have for the last 7 years diversified into hempcrete products such as blocks and panels and supplying on-site installation of cast hempcrete.


Hempcrete Block for Mexico and Central America (online presentation)

Steven Clarke Heavengrown, Mexico.

An expert in sustainable engineering and also a natural builder, Stephen has put his energy into applying hemp building technology in his native country of Mexico and other parts of Latin America. Together with Heavengrown, they work to help people grow hemp and to grow their homes. He has built many projects and developed some hempcrete alternatives that include coconut fibres, agave fibres and sugar cane bagasse fibres.


Hempcrete and Mycelium composite panel system

Ingmar Nopens C Biotech – Belgium.

Ingmar Nopens holds a MSc in Bio-science engineering in environmental technology and a PhD in Applied Biological Sciences. He is a full professor at Ghent University leading research in the context of resource recovery and circular economy. End of 2022 he joined C-Biotech as process manager, leading the efforts to develop and industrialise sustainable, biobased and circular materials for the construction sector using industrial hemp as biomass. The mission of C-Biotech is to decarbonize the construction sector and contributing to the challenge of net-zero.


Lunch at Kanteen25.


Departure from KANTEEN25 by bus provided by the Symposium. Amsterdam-Twello

Site visit to the ‘Voorst Town Hall Facade’, Twello

Rens Borgers and de Twee Snoeken architects.

This massive example of hempcrete casting is an important example of how public buildings can be retro fitted to reduce energy consumption and make an impressive statement of the direction all governments local and national should be taking.

Twello- Amsterdam, bus return to KANTEEN25


Conclusion and end of Symposium.


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