He was born on September 7, 1883, in Ureterp, Opsterland, Friesland, Netherlands to architect Rienk Kornelius De Boer and avid gardener Antje Dictus Benedictus.
His symptoms worsened in the summer of 1908; on the basis of doctor and family advice he emigrated to the United States in October 1908 to be treated at the Dutch operated Bethesda Sanatarium in Maxwell, NM.
As a city planner, he co-authored Denver's first zoning code, helped devise many of its roadways, and led in the development of mountain parks.
He consulted for cities along the Front Range and on the Western Slope – including Greeley, Boulder, Golden, Longmont, Aurora, Fort Collins, Englewood, and Grand Junction – and far beyond, including Scottsbluff, Nebraska; Brainerd, Minnesota; Ruidoso, New Mexico; Idaho Falls, Idaho; Boulder City, Nevada; and Glendive, Montana.
More than a talented designer and a practiced aesthete, they asserted that "his was a 'voice before its time,' not only in ecological awareness, but in his concern over the 'modern' tendency towards dehumanization."