A computer-implemented method of generating building instructions for a building element model, the model including a plurality of building elements, the building instructions being indicative of a sequential order of construction steps for constructing the building element model, each construction step including adding at least one building element to the building element model. The method comprises determining, from a digital representation of the building element model, a sequential order of deconstruction steps for deconstructing the building element model into building elements, each deconstruction step including removing at least one building element from the building element model; and inverting the determined sequential order of deconstruction steps to obtain the sequential order of construction steps.