Conferences and Exhibitions, VentusAR

SNH Visual Impact Consultation

Visual Representation of Wind Farms
Scottish National Heritage (SNH) provide good practice guidance for the visual representation of wind farms. Derived from research and publications for over 10 years the documents provide a standard for production of visualisation methods and methodologies that are used widely in Scotland and referenced widely. In 2012 a consultation and review process began on the guidance and a draft consultation was published in May 2013.

The original reference document is available here:

The consultation process is available at:

As detailed in the current documents, the guidance draws heavily on the ‘Guidelines for Landscape and Visual Impact Assessment’ (GLVIA), produced by The Landscape Institute and Institute of Environmental Management and Assessment (2002) – this guidance was updated and republished in 2013 (

Within the last few years other local authorities, particularly Highland Council (updated May 2013), have published their own “Visualisation Standards for WindEnergy Developments” (link here: Additionally research studies from, amongst others the University of Stirling (ExecutiveSummary-PDF) have added to the understanding of visual perception.

All this history (the above is a summary and not a complete historical timeline) has lead to SNH to reviewing and republishing the guidelines for consultation with the aim, from the Minister, to “develop an objective, verifiable, single approach to wind farm visualisation“. This week (half-way through the 8-week process), at SNH Battleby conference centre, about 40 parties debated the questions raised by the consultation.

In attendance, our observations were that

  • The previous attendance was not considered prescriptive enough
  • All images should be verifiable (but without a definition of the depth of definition)
  • However, there should be proportionate effort and resources
  • That prescriptive use of specific hardware or software was liable to misuse
  • New approaches such as the use of subtended angles should be considered
  • Limits of visual acuity and definition of impact require review for distant viewpoints
  • Named datasets and sources were liable to change and specifications are more important
  • Policing of guidance (by LAs / SNH) is as important as publication of specifications
  • Lack of definitive and accurate sources for turbine locations is an issue for cumulative
  • Viewpoint selection and revision should be more fluid through the development lifecycle

The distinction between visualisation as a appearance in the landscape, supported by the recent research into the use of 75mm imagery is however compromised (when not onsite) by the limited view in a single-frame image.  When assessing the impact of a development in the local context a 50mm or wider image provides a greater field of view.  The use of multiple images by different levels of users both on-site and in isolation continues to provide conflict in limiting the publication of images.

Accuracy and precision in visualisation is important – but the landscape impression is more so.  When micrositing can result in several tens of meters in movement between the scoped and planned development and final construction location then issues in precision of a few meters in viewpoint location or observed heights can be the lesser of the overall issues involved.

We shall be submitting our input to the process in the next few weeks.  Good luck to SNH to get consensus and guidelines published by the end of 2013.