AVR Levels vs Visualisation Types
By Marc Sawan
AVR Levels and Visualisation Types are often treated as though they belong to the same classification system.
They do not.
An AVR Level describes what information about the proposed development is shown. A Visualisation Type describes the technical approach used to produce and present the image.
The confusion is understandable. Both use numbered classifications, both appear in guidance used for planning visualisations, and terms such as "AVR Type 4" are still regularly used in briefs and viewpoint schedules.
But combining the two can create real ambiguity when a project is being scoped. A fully rendered image is not automatically the most rigorously verified, and a simple wireline can be produced using a highly controlled and verifiable process.
Understanding the difference makes it much easier to specify exactly what is required.
1 | Two Different Questions
The Landscape Institute's TGN 06/19 defines four Visualisation Types.
These range from Type 1 annotated viewpoint photographs through to Type 4 photomontages or photowires produced using quantifiable data and a verifiable technical methodology.
The Visualisation Type therefore relates to the way the image is produced, the equipment and information used, the required level of accuracy and the way the result is presented.
AVR Levels come from Appendix C of the London View Management Framework and answer a different question: how much information about the proposed development should the image show?
The scale runs from AVR0, which establishes location and size, to AVR3, which adds the proposed materials.
A useful way of thinking about the distinction is:
Visualisation Type - how the image is produced and verified.
AVR Level - what the image shows.
The two decisions are related, but they are not interchangeable.
2 | Where Each Scale Comes From
The AVR Level classification is set out in Appendix C of the London View Management Framework:
AVR Level | Shows |
|---|---|
AVR0 | Location and size of proposal |
AVR1 | Location, size and degree of visibility of proposal |
AVR2 | As AVR1, plus a description of architectural form |
AVR3 | As AVR2, plus the use of materials |
The Landscape Institute's TGN 06/19 uses a separate four-part classification:
Visualisation Type | Aim |
Type 1 | Annotated viewpoint photograph showing context and the outline or extent of development |
Type 2 | Non-photographic 3D wireline or model showing the form of the development or context |
Type 3 | Photomontage or photowire showing appearance, context, form and extent |
Type 4 | Photomontage or photowire using quantifiable data and a verifiable methodology to represent scale, appearance, context, form and extent |
TGN 06/19 makes the relationship between the two explicit. It states that the graphical approaches used for AVR Levels 0-3 may be applied to Visualisation Types 3 and 4.
This is useful because it confirms that they describe different characteristics of the same image.
One classification tells you the technical approach being used. The other tells you how much of the proposed development is being represented.
3 | How They Combine, and Where They Don't
For Type 3 and Type 4 photomontages or photowires, an AVR Level can be used to define how the proposal should be represented.
For example, the same underlying viewpoint might be required as:
Type 4 - AVR1
Type 4 - AVR3
Both can use the same photography, camera position, 3D model and alignment.
The difference is what is shown in the finished image.
The AVR1 version concentrates on the location, size and visibility of the proposal. The AVR3 version adds the architectural form and proposed materials.
The distinction between Type 3 and Type 4 is different:
AVR Level | Type 3 | Type 4 |
AVR0 | Location and extent shown using a Type 3 methodology | Location and extent shown using quantifiable Type 4 data and methodology |
AVR1 | Position and visibility shown | Position and visibility shown using the higher level of verifiability required by Type 4 |
AVR2 | Architectural form shown | Architectural form shown using Type 4 methodology |
AVR3 | Materials and appearance shown | Materials and appearance shown using Type 4 methodology |
A Type 3 AVR3 can therefore be fully rendered without providing the same level of verifiability as a Type 4 image.
Equally, a Type 4 AVR1 may appear visually much simpler while having been produced using more rigorous technical information and processes.
Type 4 should not, however, automatically be read as "survey verified". TGN 06/19 requires quantifiable verification data and sufficient locational accuracy, but the degree of survey input should be proportionate to the viewpoint, its sensitivity and the purpose of the assessment.
For close or particularly sensitive urban and heritage views, precise survey of the camera position and visible reference points may be appropriate. For other views, a different level of locational accuracy may be sufficient.
4 | Why This Gets Conflated So Often
Part of the confusion comes from the numbering.
AVR Levels run from 0 to 3. Visualisation Types run from 1 to 4. Both are used when discussing planning visualisations, sometimes within the same project.
There is also a terminology problem within the guidance itself.
Appendix C of the LVMF asks each AVR to identify the "AVR type", meaning which visual properties are shown.
In practice, this is what is now commonly referred to as the AVR Level.
TGN 06/19, published later, uses the word "Type" for its separate Visualisation Type 1-4 classification.
It is therefore easy to see how expressions such as "AVR Type 4" have entered everyday use.
The problem is that the phrase is ambiguous. Does it mean a Type 4 visualisation, an AVR3 rendered image, or both?
Using the two classifications separately avoids that uncertainty.
5 | Specifying Both Correctly
A brief or viewpoint schedule should make clear what is required from each image.
The Visualisation Type should identify the technical approach. Where an AVR Level is being used for a Type 3 or Type 4 image, this should be stated separately.
For example:
Type 4 - AVR1
or:
Type 4 - AVR3
The methodology can then record the technical information behind the image, including the method used to establish the camera position and the level of locational accuracy appropriate to the view.
This is much clearer than simply asking for an "AVR Type 4".
Likewise, AVR Level 4 is not a classification within the LVMF. The AVR scale ends at AVR3.
Keeping the terminology separate at briefing stage helps the visualisation studio, planning consultants and Local Planning Authority understand exactly what is being commissioned and avoids assumptions later in the process.
Key Takeaways
AVR Levels and Visualisation Types describe different things. The Visualisation Type relates to the technical approach used to produce and present the image. The AVR Level describes the information shown about the proposed development.
AVR Levels run from AVR0 to AVR3. There is no AVR Level 4.
Visualisation Types run from Type 1 to Type 4. Type 4 provides the highest level of accuracy and verifiability within TGN 06/19.
AVR Levels can be applied to Type 3 and Type 4 photomontages and photowires. A Type 4 image can therefore be produced at different AVR Levels depending on what needs to be communicated.
More visual detail does not automatically mean greater technical verification. A fully rendered AVR3 can use a Type 3 methodology, while a visually simpler AVR1 can use a Type 4 methodology.
Type 4 does not automatically require survey verification in every situation. The required locational accuracy should be appropriate to the viewpoint, its sensitivity and the purpose of the assessment.
Both classifications should be stated separately where applicable. "Type 4 - AVR3" is much clearer than "AVR Type 4".
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Frequently Asked Questions
Is "AVR Level 4" a real classification?
No. The LVMF AVR classification runs from AVR0 to AVR3. AVR3 is the highest level and adds the proposed use of materials to the architectural information shown at AVR2. "Level 4" usually results from the AVR Level classification being confused with the Landscape Institute's separate Visualisation Type 1-4 system.
Does a higher AVR Level mean more reliable evidence?
No. AVR Level describes how much information about the proposed development is shown. It does not define the technical accuracy or verification method used to produce the image. An AVR3 contains more visual information than an AVR1, but it is not automatically more accurately positioned. The Visualisation Type and methodology provide the information needed to understand how the image has been produced and the level of technical verification behind it.
Can a Type 3 image be produced at AVR Level 3?
Yes. TGN 06/19 specifically notes that the LVMF AVR0-3 graphical approaches may be applied to Visualisation Types 3 and 4. A Type 3 AVR3 can therefore show the architectural form and proposed materials without using the full Type 4 methodology. Whether Type 3 or Type 4 is appropriate should be determined separately, based on the purpose of the image, the sensitivity of the setting and the requirements of the assessment.
Why do practitioners and LPAs mix these terms up so often?
The terminology is genuinely easy to confuse. Both systems use numbered classifications and are often discussed alongside each other. The LVMF also uses the expression "AVR type" to describe which visual properties are shown, while TGN 06/19 later adopted "Visualisation Type" for its separate Type 1-4 system. Using the full terms AVR Level and Visualisation Type removes most of the ambiguity
About Eye-kon
At Eye-kon, we establish the Visualisation Type and AVR Level separately so that each viewpoint is produced to the technical standard and level of detail actually required.
We coordinate the photography, survey information and camera alignment accordingly, then produce the appropriate output, from a clear AVR1 wireline to a fully rendered AVR3. Any project-specific requirements or constraints are recorded in the methodology so that the finished views are straightforward to understand and review.
