Lavrenčič was born on 24 February 1925 in Rogaška Slatina and died on 5 July 1996 in Celje, where he had moved with his family in 1929. He attended the Ljubljana School of Arts and Crafts. In 1950 he enrolled at the Ljubljana Fine Arts Academy, where he studied painting under Gojmir Anton Kos, Marij Pregelj and Gabrijel Stupica. He graduated in 1954.
From 1954 to 1965 he taught art at primary schools in Laško, Žalec and Celje. Later, he became a freelance artist. He left an indelible mark on the cultural life of Celje with his interior designs for public buildings and stage designs for the Slovensko Ljudsko Gledališče theatre (1962-1981). He also took part in the founding of the local Likovni Salon gallery (1965). For his stage designs for the theatres Slovensko Gledališče in Trieste, Slovensko Narodno Gledališče in Ljubljana and Maribor, Mestno Gledališče Ljubljansko and Mladinsko Gledališče Ljubljana, he received two Borštnik Awards (in 1972 and 1974), and then in 1974 he also received the Prešeren Fund Award for his paintings and stage designs.

Lavrenčič is one of the few surrealists in Slovene painting. The first intimations of his style can be found in his studio series of gouaches entitled "The Sea" from the 1960s and in his images of the hilly Slovene landscape that are abstracted lyrical interpretations, floating in midair. In the 1970s the landscapes in his paintings were replaced with fantastic figures or their parts, mannequins, draperies and objects in unusual combinations in front of an ethereal, undefined background or a distant horizon. Rather than interpretations of the subconscious, these images are the artist's observations about the world and its phenomena.