Visualisations of 3D cadastral information incorporating both intrinsically spatial andnon-spatial information are examined here. The design of a visualisation prototype islinked to real case 3D property information. In an interview with domain experts, thefunctional and visual features of the prototype are assessed. The choice of renderingattributes was identified as an important aspect for further analysis. A computationalapproach to systematic assessment of the consequences of different graphical designchoices is proposed. This approach incorporates a colour similarity metric, visualsaliency maps, and k-nearest neighbour (kNN) classification to estimate risks ofconfusing or overlooking relevant elements in a visualisation.The results indicate that transparency is not an independent visual variable, as itaffects the apparent colour of 3D objects and makes them inherently more difficult todistinguish. Transparency also influences visual saliency of objects in a scene. Theproposed analytic approach was useful for visualisation design and revealed that theconscious use of graphical attributes, like combinations of colour, transparency andline styles, can improve saliency of objects in a 3D scene.