This paper discusses the visualization tools and methods used to examine human perception in Visual Impact Assessment (VIA). One of the key conservation areas in Kuala Lumpur was selected in the study to measure the impact of different types of visualization tools. This paper recommends that human perception contributes towards the improvements of the visualization tools for VIA. The study found out that the common visualization tools used were not the most preferable tools among respondents. On the contrary most respondent preferred interactive visualization that offered more visual possibilities leading to a better understanding of landscape design. Apart from this, the study identified that the visual perception between the respondents who have different formal education background have similar concerns on the visualization tools tested to them.