One day in the not-too distant future, glass windows may be a thing of the past. Researchers in the US have revealed a surprising window material that could be stronger, more energy-efficient and have less glare – transparent wood.

Engineers at the A. James Clark School of Engineering at the University of Maryland have demonstrated through a study how wood could one day provide shatterproof, thermally-insulated alternative to glass for windows in both houses and large public buildings.

The unorthodox window-making process starts with bleaching wood of its lignin – the component that makes it both brown and strong. The material is then soaked in epoxy, which adds strength back and makes the wood both clear and waterproof.

Tests undertaken by the research team showed that light travelling through the resultant transparent wood is more softly and evenly distributed around a space than it is through glass.

The angle at which light shines through the wooden windows does not change as the sun moves, as happens with traditional glass windows, because the natural channels in the wood direct the sunlight in the same way every time.

“The window is very transparent, but still allows for a little bit of privacy because it is not completely see-through,” said Tian Li, the lead author of the study. “We also learned that the channels in the wood transmit light with wavelengths around the range of the wavelengths of visible light, but that it blocks the wavelengths that carry mostly heat. So while transparent wood lets through just a little bit less light than glass it lets through a lot less heat.”

The research team – which includes members of the university's department of materials science and engineering and energy research centre – has had its findings published in the Advanced Energy Materials journal. Initial tests have been carried out on small squares of linen wood, but the researchers claim wood of any size could be used.