Independent of the landscape, or design of the proposed site, the visibility of the site to the general public in the surrounding area represents a fundamental dimension in establishing the degree of change to the visual amenity of the area surround a proposed site.
As described in the previous section (Design Recommendations), the visual sensitivity index establishes the visibility of the proposed site which combined with the Design Compatibility percentage creates a quantitative measure of visual change.
It may be worth noting, that even a poorly designed site relative to the surrounding landscape may represent a low degree of visual change if it is located in a remote area where there is not immediate access to the site, and it is located away from populated areas. The other extreme is where a highly compatible design which has all possible efforts expended to reduce it's visual disamenity, might still be "obvious" if located in a high traffic area without any vegetation or other buildings to blend in with (i.e. a flat, open field with no woodlands or tree groups) thereby reflecting a need to consider it's location relative to visual amenity.
There are 6 factors which are considered according to the definitions below:
Below is an example of ASDF Design Guidelines based on a residential land use:
4: Highly visible site (open)
3: Large vistas and avenues to and from the site and surrounding landscape
2: Views and Vistas to and from the site and surrounding landscape
1: Glimpsed views between building and vegetation
4: Prominent within the line of sight
3: Elevated within the line of sight
2: Above the line of sight
1: Out of the eyeline
4: Continuously visible in the surrounding area
3: Partly visible, some screening
2: Brief views when travelling within the landscape
1: Specific views from static locations
4: Highly visited site
3: Moderate visitation
2: Low visitation to the site
1: Occasional visitation
3: Isolated items (street lights, small scale distribution lines - services)
2: Groups of elements (road lighting, large scale distribution lines - services)
1: Large Infrastructure (transmission lines, freeway lighting, major pipelines)
4: Designated cultural precincts or landscapes classifications
3: Distinct Landmarks and recognized features
2: Notable features and significant landscapes
1: No significant elements
The resulting score provides a quantitative measure of the visibility of the site relative to the surrounding features. This represents the final step towards establishing the Degree of Visual Change.