HIGH Performance

In 2014, Belgian architect Robbe Van Caimere, a principal of Martens Van Caimere Architecten, was hired to retrofit a bungalow near Ghent. The place dated to the middle of the last century and had no insulation. Structural brickwork simply supported interior plaster and an exterior brick veneer separated by a five-centimetre cavity. “Belgium has cold winters, but the house was built before the seventies oil crisis,” Van Caimere says. “Energy was cheap.”

To improve the home’s efficiency, the architect first considered infilling the walls with insulation derived from either paper or wood chips. But the gap between the brick and exterior