Visual Impact Assessment
Plans and elevations describe a proposed development, but they do not always show how it may appear within an existing view. Photomontages can help bridge that gap by placing the proposal into photography from a defined assessment location.
In Brief
Photomontages can be used in a Visual Impact Assessment to show how a proposed development may appear within an existing view from a defined location. They can support comparison between existing and proposed conditions and, depending on the methodology, help assess visual change or illustrate proposed mitigation. They are not required for every VIA; their use depends on the project, assessment scope and applicable planning requirements.
Within a Visual Impact Assessment, a photomontage is a visual representation that places a proposed development within photography of the existing environment from a defined assessment location.
Its purpose is to help communicate the relationship between the proposed development and the view in which it may be experienced. This can make aspects of visual change easier to understand than plans, elevations or written descriptions alone.
A photomontage used for visual assessment should therefore be understood as assessment evidence rather than simply as a design illustration. Its role is connected to a particular viewpoint, an existing visual condition and a proposed change.
No. A photomontage is not automatically required for every Visual Impact Assessment.
Whether photomontages are appropriate or required depends on factors such as the type and scale of development, the assessment scope, the applicable planning pathway, project-specific requirements and the visual assessment methodology being used.
Some project-specific guidance requires photomontages as part of a more detailed visual assessment. In other circumstances, the necessary visual evidence may be different. A planning authority or project brief may also identify particular viewpoints or visual material that needs to be provided.
For this reason, the need for photomontages should be established from the requirements of the particular project rather than assumed at the outset.
One of the main functions of a photomontage is to support comparison between the existing visual condition and the proposed condition.
Existing photography records the view from a particular location. The proposed development can then be represented within that view using appropriate project information. This can help communicate where the proposal would appear, its apparent scale and position, how much of it may be visible and its relationship with existing buildings, vegetation, landform and other visual elements.
Depending on the methodology, this visual evidence may contribute to understanding the nature or extent of visual change from that location.
A photomontage does not, however, determine the visual impact by itself. It provides evidence that needs to be interpreted within the wider assessment.
A VIA photomontage is not intended to make a proposal look attractive. Its purpose is to help represent the proposed visual change from a defined assessment location.
A photomontage gains its assessment meaning from the location it represents. The image is not simply a general impression of the development within the surrounding area; it represents the proposal from a particular viewpoint.
That makes viewpoint selection an important part of the process. A location may be chosen because it represents a relevant visual receptor or group of receptors, a particular viewing condition or another view that needs to be examined under the applicable assessment requirements.
A technically detailed image from an unrepresentative location does not necessarily provide the evidence needed to understand the visual effects that matter to the assessment.
For more on this part of the assessment process, see How Are Viewpoints Selected for a Visual Impact Assessment?
Yes, depending on the assessment methodology. Photomontages can provide visual evidence that helps an assessor understand how substantial the proposed change may appear from a particular location.
They may help illustrate matters such as apparent scale, the visible extent of the proposal, its position within the view, screening and its relationship with the existing visual environment.
These are relevant to understanding magnitude of visual change, although the way magnitude is determined depends on the methodology applicable to the project.
The photomontage therefore supports the assessment; it does not replace the methodology or provide a magnitude rating automatically.
Photomontages can also be used to illustrate how proposed visual mitigation may alter a view. Depending on the project, this may include proposed vegetation screening or other design responses intended to reduce or modify visual effects.
This can be useful where the effectiveness of mitigation needs to be understood visually rather than described only in text or on a plan.
However, proposed vegetation should not simply be treated as an immediate opaque screen. The representation needs to reflect the assumptions relevant to the assessment, such as the location and intended form of planting and, where applicable, the stage of establishment being represented.
A photomontage can therefore help communicate the expected visual role of mitigation, but it should not be interpreted as a guarantee that future conditions will reproduce the image exactly.
Not necessarily. Architectural visualisations and VIA photomontages can both depict a proposed development, but they may be prepared for different purposes.
An architectural render may be used to communicate design intent, form, materials, atmosphere or the experience of a proposed space. Its viewpoint and presentation may be selected primarily to explain the design.
A photomontage prepared as visual assessment evidence has a different role. It needs to relate the proposed development to an identified existing view from a defined assessment location so that the resulting visual change can be examined in context.
An architectural visualisation may still provide useful project information, but it should not automatically be treated as equivalent to a photomontage prepared for a Visual Impact Assessment.
No. A photomontage is a visual assessment tool rather than a literal reproduction of human vision.
Human vision is dynamic. People move their eyes and head, experience depth, respond to changing light and weather, and perceive a place within a much wider field of experience than a single static image can reproduce.
The way a photomontage is displayed can also affect how the represented development is perceived. A wide panoramic image reduced to a small size on a page or screen, for example, may make visual elements appear less prominent than they would when the image is viewed at an appropriate scale.
This does not make photomontages unsuitable for visual assessment. It means their preparation and presentation need to be understood as part of the evidence. The reliability of that evidence is a separate technical question from whether a photomontage is needed in the first place.
Preparing a useful photomontage begins with enough information to establish both the existing view and the proposed development within it.
Depending on the project and methodology, this may include an identified viewpoint and suitable site photography, current design information, project location and orientation, relevant dimensions or levels and sufficient geometry to represent the proposal within the photographed scene.
Additional information may be needed where materials, colours, landscaping, screening or other design characteristics materially affect the visual representation being prepared.
The exact inputs depend on the project. For a broader overview of the documentation that may be needed at the start of an assessment, see What Information Is Needed for a Visual Impact Assessment?
The need for photomontages can arise from several parts of the assessment process rather than from one universal rule.
Applicable planning guidance may identify visualisation requirements for particular project types. A consent authority, project brief or project-specific assessment requirement may nominate particular visual material or viewpoints. In other cases, the visual assessment methodology may identify photomontages as useful evidence for understanding particular visual effects.
The scope should therefore be reviewed early enough to establish whether photomontages are required and, if so, what they need to represent.
This also helps avoid producing visualisations that do not correspond with the viewpoints, project information or presentation requirements relevant to the assessment.
Photomontages are most useful when they form part of a wider body of visual evidence rather than being treated as the assessment itself.
A Visual Impact Assessment may need to consider the relevant visual receptors, representative viewpoints, existing visual conditions, the proposed development and the nature of the resulting visual change. Depending on the methodology, visual sensitivity and magnitude may then contribute to the evaluation of visual effects.
A photomontage can make parts of that relationship visible. It can help the reader compare conditions and understand what the proposal may look like from an identified location, but the image still needs the context and reasoning of the wider assessment.
Used this way, photomontages are not simply presentation graphics. They become one part of the evidence used to communicate and assess proposed visual change.
Continue Reading
A photomontage represents a proposal from a particular assessment location. Learn why representative viewpoints are selected and what makes a viewpoint relevant to the wider assessment.
Understand viewpoint selection →Visual Impact Assessment
Photomontages may form part of a Visual Impact Assessment, but the appropriate evidence depends on the proposal, relevant viewpoints, planning requirements and assessment methodology.
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