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Workers unloading VELUX roof windows from a truck at a construction site.
1941-1951

With materials in short supply in wartime Denmark, Villum Kann Rasmussen developed the first VELUX roof window that would transform dark attics into domestic spaces.

Inventive entrepreneur fills loft spaces with daylight and fresh air

In 1941, the young engineer Villum Kann Rasmussen established his company V. Kann Rasmussen & Co in Copenhagen. One of his first commissions was to supply roof windows to a number of school buildings, in which loft space was being converted into classrooms. The shortage of materials during the war led Villum to come up with an idea that would transform those dark empty attics into bright living spaces – full of daylight and fresh air.
Workers handling window frames outside a brick building.
A historic moment, the first delivery of type BB windows to Slagelse Vestre School.

Vision and success

His vision was “to make a skylight - a roof window - that is just as good as the best vertical window”. Villum’s first roof window was patented in 1942. He called it VELUX – ‘VE’, from the word ‘ventilation’ and ‘LUX’, from the Latin word for ‘light’. VELUX roof windows proved to be an effective way of putting many square metres of wasted roof space to good use. Post-war demand for VELUX roof windows increased significantly, and the young company’s prospects looked bright. Villum’s belief in a fair deal, high quality standards and ongoing technical innovations and improvements were key to his success.
Vintage office with large windows and a person working at a desk.
Villum Kann Rasmussen (KR) at work in his own new company.