The paper presents the new find of a complex oven discovered within a closed context of a LN house on the tell Bapska (Croatia), a site belonging to both the Sopot and the Vinča Cultures.  Extensive (and ongoing) analyses so far point out that the installation shows some very advanced and fundamentally innovative architectural features related to mixture of used clay, thermodynamical aspects of dome opposite to the fireplace, and others. Computer models also show that heat flux (ϕ) was of paramount importance during design and building of the installation, resulting in significant leap forward in household and/or production furnaces.