The present invention relates to a construction kit (B) comprising a position element (2) comprising at least one position pocket (21A, 21B, 21C, 21D) for positioning a construction plate (1), wherein the position pocket (21A, 21B, 21C, 21D) extends in a plane from an origin (0) in an imaginary three-dimensional coordinate system and comprises two interacting and opposite holding means (20A, 20B) with a distance (b) between them for holding the construction plate (1) in place, that the position pocket comprises a corner (h1) with an angle (v1) of 90° and two edges extending from said origin and forming said angle (v1) between them, that between said two opposite holding means (20A, 20B) said edges comprise an orthogonal connection (23) forming a support for the construction plate (1), when this has been placed into the position pocket (21A, 21B, 21C, 21D), wherein said holding means (20A, 20B) comprises two fixation means (24) which are symmetrically arranged on both sides of an imaginary diagonal (d), which extends from origin (0) in an imaginary square plane and in addition are arranged to interact with fixation means (10) of the construction plate for fixation thereof. Further, the construction kit comprises a construction plate (1) comprising at least one corner (h2) for positioning of the construction plate (1) in a position pocket (21A, 21B, 21 C, 21D) in a position element (2) according to the invention, which corner (h2) has a flat extension which at least comprises the extension of said position pocket (21 A, 21 B, 21 C, 11 D), wherein said corner (h2) starts from en origin (0) in an imaginary three-dimensional coordinate system and has an angle (v2) in the region of 45° to 90° with an imaginary diagonal (d) concerning a square plate, which diagonal (d) extends from origin (0), wherein the construction plate comprises at least one fixation means (10) arranged to interact with fixation means (24) of the position element (2), wherein said fixation means (20) is arranged beside said imaginary diagonal (d).