Continuous lines must not consist of several line segments and there should be no remnants of the old congruent lines. Do not place several identical entities on top of each other.

The content of the model files shall be placed correctly in relation to the agreed project coordinate system. The models shall be modelled in exact dimensions corresponding to the physical elements.

The graphics in the designed model files should be divided into project agreed layers/levels in a manner that will allow other parties to turn off elements that are irrelevant to them (e.g. utility pipes on a different level than texts and dimensions relating to them). Model files must only contain relevant elements and layers/levels.

Shapes (types: shape, complex shape, polyline and ellipse) shall, for the sake of further processing, always be executed as closed elements. Where lines define a delimited area, the lines should be drawn as a closed shape (continuous line without cessation or duplication).

Shapes that are to be plotted as filled shapes (with a raster pattern or with a colour) must have the fill and the border placed on separate layers/levels, so that each part can stand alone.

Designed model files should be of an appropriate size, depending on the chosen application and content of the files. A maximum of 20 MB will be usable for most types of files. Terrain models may generate larger files eg. 50 MB. It is recommended that these size limits are agreed on during the design process.

Designed model files must be divided in disciplines relevant to the project, and only contain elements of that discipline.

Designed model files must only contain one model environment and one layout environment.