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 was key to his success.