How it began
The Demerara window developed in Guyana in the 18th and 19th centuries, when the territory was under Dutch and then British rule. Builders working in European styles adapted them to a hot, humid climate, and this window was one result. No individual designer is recorded. It takes its name from Demerara, the colonial region around Georgetown.
How it works
The window is a sash fitted with a louvered timber shutter hinged at the top. The shutter is pushed outward at the bottom and held on a wooden prop, so it slopes away from the wall. In that position it shades the opening from direct sun and rain while air passes through the louvers and the perforated side panels.
Some windows had a box, called a cooler, at the sill. Blocks of ice, a vessel of water or plants were placed in it to cool the air as it entered. The windows were usually made of imported pitch pine, thought to stand up to the heat and humidity better than local timber, and were normally fitted on upper floors to cool bedrooms and living rooms.
How it spread
The cooler is believed to have been a feature of wealthy households at first and was later adopted by others. The window became common on houses of all classes in Guyana and spread to other Caribbean territories. The National Trust of Trinidad and Tobago records it on a number of heritage houses and office buildings in Trinidad.
Where it stands today
With air conditioning in most modern buildings the window is no longer needed for cooling and is now built mainly for its appearance. It survives on older timber houses that keep their colonial features, especially in Georgetown, and is often described as the colonial forerunner of air conditioning.
