Robots could harvest lava from volcanic eruptions to make 'concrete' of the future

After repeated volcanic eruptions near a fishing town in Iceland, two architects are pushing a novel, futuristic way to harness vast lava fields - by turning molten rock into a construction material.

Since December 2023, there have been nine volcanic eruptions near the coastal town of Grindavik, forcing residents to regularly evacuate.

Arnhildur Palmadottir, founder and owner of Reykjavik-based s.ap arkitektar, says she and her son, Arnar Skarpheoinsson, came up with the idea in 2018, after the 2014-15 Holuhraun eruption, the largest outbreak in Iceland for over 300 years.

She said: "We had this eruption in Holuhraun, which is close to Vatnajokull, the biggest glacier that we have, and we had like an enormous amount of material just running over the landscape. And when we saw those numbers we thought, 'whoa, I mean this is like molten concrete in a way, without the cement, so why can't you just do something with it?'"

Their lava-forming proposal focuses on how the destructive force of lava might be used to transform the global construction industry, which is heavily reliant on concrete, steel, and other high-impact materials.

Palmadottir and Skarpheoinsson believe a lava flow could contain enough building material for the foundations of a city to rise in a matter of weeks, without the climate impacts associated with traditional construction.

However, they don't expect their vision to become a reality until around 2150.

For the project, human construction workers wouldn't be able to handle the lava due to temperatures comparable to molten glass, according to those involved in the project.

Instead, the various methods and technologies would be used to shape and mould the rock into desired forms - from 3D printing, controlled flows, cooling chambers, and robots.

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"We think about it as robots that would travel the lava fields and just kind of gather the molten lava and then create some kind of structures out of that," said Palmadottir.

She also referred to the prefabrication method, which would enable them to guide the molten lava into a factory where pressure and heat would be used to bring about results.

The architects argue volcanic basalt rock is similar to traditional construction concrete used today, but would be available at virtually no cost.

They say basalt and lava could be transformed into durable, low-impact building elements.

"We have seen that lava can be very different. It has different material properties," said Skarpheoinsson.

"We can see in nature columnar basalt that's very crystallised and very strong and could theoretically be used as a structural material."

Palmadottir said Iceland's construction industry has expressed an interest, as it seeks ways to reduce its carbon impact.

"The building industry is interested in this because, for example, concrete producers have to lower their CO2 emissions because it's the biggest emitter in the building industry," she said.

"And also, they are using this material already and concrete is 98% basalt anyway."

The project was Iceland's contribution to the 19th International Architecture Exhibition of the Venice Biennale in 2025.

"This project is about shifting perspective," said Palmadottir.

"What would it mean to live in a lava-built city? What would that change about architecture, about how we relate to the land and to each other?"

(c) Sky News 2026: Robots could harvest lava from volcanic eruptions to make 'concrete' of the future