Researchers develop brick of the future

The better a building is insulated, the less heat is lost in the winter. Traditionally, insulating layers are applied to the finished walls, but increasingly self-insulating bricks are being used. Some of these have air-filed chambers, others have larger cavities filled with insulating materials such as perlite. However, these insulating bricks are usually considerably thinker than normal bricks, explains the Federal Laboratories for Materials Science and Technology (Empa). 

Empa researchers have now developed an alternative solution that makes it possible to build thin yet highly insulating walls by replacing perlite in insulating bricks with aerogel, a highly porous solid with very high thermal insulation properties that can withstand temperatures of up to 300 degrees Celsius.

“The material can easily be filled into the cavities and then joins with the clay of the bricks,” said Empa researcher Jannis Wernery. “The aerogel stays in the bricks – you can work with them as usual.”

Called ‘aerobricks’, the Empa invention has far better insulating properties than perlite-filled bricks. To achieve the required insulation values, a wall of perlite brick must be about 35 per cent thicker than an aerobrick wall.

The comparison with ordinary brickwork made of non-insulating bricks is even more pronounced: a conventional wall would have to be almost two metres deep to insulate as well as an aerobrick wall of just 20 centimetres deep.

For now, aerogel is still very expensive – a single square metre of wall made of aerobricks would cost an additional 500 Swiss francs. Experts, however, expect that the costs for aerogel will fall massively in the near to medium term.