Careers Advice: guidance on good practice in assessing landscape impacts of developments

Written by: Chris Kennett
Published on: 29 Sep 2017

landscape

Much of my professional life has been concerned with assessing the landscape and visual impacts of proposed development, where a common challenge has been securing high standards of photography and photomontage as planning evidence for the likely visual impacts. The following hopefully helps by providing simple guidelines for better practice and pointers to best practice.

1: Select appropriate vantage points: A representative range of vantage points should demonstrate an observer’s experience of the proposed development site from the wider public realm (not private views) based on the site’s ‘visual envelope’.

A site’s visual envelope can be established through fieldwork, computer modelling or a combination of the two; neither is perfect and I prefer a combined method. A computer-generated model of what is known as the ‘Zone of Theoretical Visibility (ZTV)’ is relatively easy and quick to produce, generated from theoretical lines of sight between the proposed development and the surrounding area using landform only, taking no account of intervening buildings, trees or other visual barriers. It usefully identifies all areas with potential vantage points of the proposed site, which can then be confirmed or disproved through fieldwork. This is a reliable and fast way to capture key vantage points whereas more complex computer modelling involves more time, cost and can easily fail to identify real-world vantage points if not done properly.

Sensitive key views may be (and should be) identified in the council’s local plan; examples include vistas towards historical landmarks or panoramic views across the countryside from an elevated vantage point. However, well-used public locations are also potential key vantage points – public parks, busy streets, popular footpaths and tourist locations for example. Sometimes it can be helpful to illustrate such sensitive views within the visual envelope to demonstrate the proposed development site is not visible from there.

Further guidance on this can be found in Chapter 6 of the professional publication 'Guidelines for Landscape & Visual Impact Assessment', 3rd Edition (Landscape Institute/Institute of Environmental Management and Assessment, 2013).

2: Provide clear photographic evidence: A frequent fault with photographic evidence for views, visibility and visual effects of development is the use of a wide-angle photograph in combination with a small print size. Most of us are accustomed to the 6” x 4” prints from the days of film cameras, which typifies photographs included in reports, but this doesn’t come close to conveying the scale and detail of what a person would see ‘in the field’ with the naked eye. The limited resolution of most printing devices* and/or image compression in PDF files make this even worse. Therefore, making planning judgements about visual impacts based on such images is fundamentally flawed.

Standards for Landscape & Visual Impacts Assessment (LVIA)** require the reader to be presented with a photograph or photomontage that conveys a similar scale and level of detail as would be seen in the field with the naked eye. Interpreting this is a technical and somewhat confusing exercise, with professionals guided by the Landscape Institute amongst others (see below). As a very rough guide though, a single frame photograph should typically be printed to the full width of an A4 or A3 page in ‘landscape’ orientation if it is to even begin to be valid as evidence of views, visibility or the visual effects of development, whether part of a LVIA or not. This should be a standard requirement for photographic evidence in any planning submission.

3: And finally …: Producing photomontages is expensive so be kind to your clients – do your homework and only ask for those that you really need!

* A detailed explanation of this can be found at https://forums.adobe.com/thread/370714.

** Photography and photomontage in landscape and visual impact assessment (Landscape Institute, Advice Note 01/11); also, Visual Representation of Wind Farms, Version 2.1 (Scottish Natural Heritage, 2014), endorsed by the Landscape Institute.

Chris Kennett is Natural Environment and Urban Design officer at Wycombe District Council