Born in 1874 in Harlingen. He moved to The Hague in May 1897 to join Rozenburg, where his older brother W G F Jansen already was working as a Master Painter. He started as a learner and became a journeyman before he left Rozenburg in April 1898, at the same time as his brother. The latter immediately moved to Gouda and joined PZH. Jan joined him in Gouda in August 1898. He left Gouda in August 1899 for Harlingen, but soon after joined his brother in Haarlem.
To date, we only know one early wall plate that has the monogram of Jan Jansen.