02/06/2026
Is there a better way to insulate our draughty homes?
It has insulated components on rovers sent to Mars, extracted toxic contaminants from water, some even speculate that the US military has put it inside nuclear warheads.
But it could be just the thing for your bay windows.
Aerogel is often described as the most effective insulating material known to science.
While aerogel strips or panels have been used in buildings for decades, this type of insulation remains a little-known and rather expensive option for those aiming to reduce heat loss from their homes.
Given that British houses are generally pretty poorly insulated, yet we live in an age when energy efficiency is paramount, could aerogel be about to find a bigger niche in the construction and retrofit industries?
In the late 1920s or early 1930s - no-one is quite sure - two chemical engineers in the US came up with a way of removing liquid from a silica gel substance while leaving behind an ultralight, highly porous structure that one of the engineers, Steven Kistler, christened aerogel.
Imagine a foam but an extraordinarily low-density foam riddled with microscopic pores - some aerogels are around 99% air. Nicknames for aerogel include "frozen smoke" and in pictures it can look like an ethereal half-gas, half-solid slice of matter.
But the intricate structure and large volume of air inside it mean that aerogel is an amazingly good insulator. It has found its way into a surprising variety of buildings.
Aerogel insulation has been used in the roof of a former church in Belfast called The Duncairn, now an arts centre, as well as a façade for a building on Pimlico Road in London, and the ceiling of a banker's residence overlooking Lake Geneva in Switzerland.
"You could have the whole house done in aerogel, we have done it," says Liam Brown, managing director of Enviroform, a Northern Ireland-based company that supplied the insulation for these projects.
[Reprint of article previously posted on bbc.co.uk]