Abstract Some advances in our methodological approach for visibility analysis (VA) and some relevant improvements of the software tool (MOYSES v4.0) are presented. Usually visibility studies and Visual Impact Assessments (VIA) are expressed as reports that are carried out only when design of projected structures is already completed. The proposal presented here provides methods and tools that can help to measure and incorporate visibility as a part of the engineering design process. Different queries can be formulated and alternative solutions can be compared during the design stage. The tools are interactive and designers can use them to visually optimise their final solutions.