Hempcrete Cabin in Iceland Tracks Its Own Performance for Science

Eighty per cent of Iceland's buildings are concrete, and nearly every building material arrives by import. Studio Lúdika, a Reykjavik practice founded by Anna Karlsdóttir and Jan Dobrowolski, built a small hempcrete cabin called Biobuilding to argue there's a better way.

The structure sits on a family-owned plot in Grímsnes, a verdant stretch of rural Iceland. Its walls are hempcrete, a biocomposite built around the hemp plant, using industrial hemp grown at Sandhóll. The crop became a legal option only recently: industrial hemp cultivation was legalised shortly before the project began, and the first growing trials succeeded.

Why two architects left London for hemp fields

The duo relocated from London to Iceland and found a construction industry they describe as rigidly dependent on imports. 'Biobuilding began when we moved from London to Iceland and found a construction industry built on concrete and imports. We set out to learn what it takes to build here with natural, locally available materials,' they explain.

The timing helped. 'An opportunity arrived at the same time. Industrial hemp cultivation had been legalised earlier that year, and the first growing trials were successful.'

There's precedent, too. Traditional Icelandic turf houses relied on locally sourced materials, so the argument isn't exotic — it's a return trip.

What is the cabin made of?

Beyond the hempcrete core, the materials list reads like a regional inventory:

• Glulam beams for structural support
• Prefabricated foundation footings, made off-site
• Solid timber joinery, lime plaster, limewash and wool
• Internal window screens made of Icelandic seaweed, developed with textile designer Alberte Bojesen

A team of growers, researchers, engineers and craftspeople assembled the project, and a group of German journeymen craftsmen — passing through on their traditional travels — helped build it. Itinerant carpenters building a hemp cabin in Grímsnes. Iceland doesn't do dull.

A 'house for the soul' with a spreadsheet

Lúdika didn't stop at completion. They monitored the building for two years, running a life cycle assessment to test how the material actually behaves in Iceland's climate. The findings cut both ways, they say, showing 'what is possible, and also what stands in the way: current regulations and certification rules are prohibitive and policies need to change.'

The pair call the cabin a 'sáluhús' — a house for the soul. That's the poetry. The policy critique is the substance.

The design borrows from Japanese teahouses: small, humble, connected to the land. 'From inside, the views are framed rather than open: low towards the mossy ground and the mountains beyond in one direction and opening up towards a wooded area in the other. Three principles guided it: a light touch on the site, natural and locally sourced materials as far as practical, and honest, unfussy craftsmanship,' the architects explain.

What happens next?

The monitoring continues. Lúdika will keep tracking temperature and relative humidity inside the cabin to determine adjustments, challenges and opportunities. Their findings go into a final report for Askur, Iceland's Housing and Construction Research Fund.

That report may matter more than the cabin itself. If hempcrete can't clear Iceland's certification rules, the demonstrator demonstrates a bottleneck, not a building type. Either way, the data now exists — and it's growing in Grímsnes, one humidity reading at a time.