For some disciplines it is relatively easy to predict the anticipated impact of a given development proposal against key criteria. For example, a proposed land use of a certain scale will generate X number of traffic movements, and this can be further refined to predict at what time of the day the traffic movements will occur, and what category of person will be on the road at that time. Similarly, it is possible to predict the volume and composition of emissions for a given land use, or the amount of noise, or the amount of light escape, and so on.
All these predicted effects can be assessed against published standards and thresholds (which we set ourselves) to tell us whether the proposal is ‘acceptable.’ If the proposal is judged to be unacceptable, then measures to mitigate these adverse effects can be sought to convert the unacceptable into acceptable.
If it is not possible to introduce adequate mitigation then it is a matter for society to decide whether the unacceptable should be put up with as part of an ‘on balance’ judgement, where the disbenefits of the proposal are outweighed by other benefits it brings about. In very simple terms, this process underpins the process of Environmental Impact Assessment (EIA).
Unfortunately, it is not quite as straightforward when it comes to assessing predicted impacts of a development proposal on the landscape, or on a view. There are no universal classifications of landscape quality to refer to. No convenient reference tables setting development type against landscape quality to provide thresholds above which we can say ‘this proposal will have an unacceptable impact upon this landscape.’ All we have is:
1.a very coarse-grained categorisation of landscapes based on the degree to which they are protected by planning policy, from national policy (National Parks, Areas of Outstanding Natural Beauty), to local policies such as ‘Areas of High Landscape Value’ or ‘Areas of Local Landscape Importance.’ In many cases these designations wash across landscapes of highly variable quality, and
2.a hierarchy of landscape character assessments, which identify the key characteristics of our landscapes from a national scale down to local. These generally exclude urban areas. Whilst these do not generally assign quality attributes to tracts of landscape, they attempt to identify their sensitivity and condition. Some set out the pressures acting upon the identified key characteristics, and generate broad aspirational policies based on the need to ‘conserve’, ‘reinforce’, ‘restore’ or ‘create’ – or a combination of these.
Whilst these landscape character assessments generally provide very useful background material, they are rarely sufficiently detailed or fine-grained to describe baseline conditions for assessing proposals at a site-specific or project-specific level. To achieve this a bespoke project-specific landscape character assessment needs to be undertaken.
The assessment of what qualities make a landscape attractive, unattractive, or anything in between, is a highly subjective area, and has unsurprisingly eluded all attempts to be converted into a science. This is critical when it gets to the nitty gritty of development plan formulation or Public Inquiries, where visual and landscape quality (and potential impacts upon them) are important but often intangible issues.
In response to this, Landscape and Visual Impact Assessment (LVIA) is a methodology evolved by the Landscape Institute (LI) and the Institute of Environmental Management and Assessment (IEMA) for evaluating the effect of a development proposal upon views and the landscape, currently embodied in the ‘Guidelines for Landscape and Visual Impact Assessment’ 3rd Edition 2013, known as the GLVIA.
An important distinction is drawn here between effects upon views and effects upon the landscape itself, hence ‘Landscape and Visual Impact Assessment.’
The methodology is based on the simple formula that the effect of a given development proposal upon landscape and visual quality will be derived from (a) the sensitivity of the landscape, and the person experiencing the change in the landscape brought about by the development proposal (known as landscape and visual receptors respectively), and (b) the magnitude of change that would be brought about by the development proposal. These principles are related directly to Environmental Impact Assessment methodology, which in brief was evolved to predict whether impacts of a development proposal upon the environment would be ‘significant’, whether they could be mitigated, and if so what would the residual effects be. This would feed into the decision as to whether the proposal is acceptable.
So far so good. To complicate matters the LI / IEMA have made it clear that for proposals that have been screened as non-EIA, it is not necessary to assess ‘significance.’
Then there is the matter of what defines ‘sensitivity.’ This is bound up with notions of condition and value / importance. This is where policy-designated or protected landscapes come in. But there may also be cultural associations related to a landscape - historical, artistic or literary. These may be of national importance (a Turner or Constable landscape), but equally may only be of local significance. In terms of the visual landscape, one person looking at a tract of landscape from within a motor vehicle on their daily commute to work would be differently sensitive to another person on a walking holiday looking at the same tract of land. Different people will have different sensitivities, depending on who they are and what they are doing.
Not to mention ‘susceptibility.’ What is the capacity or capability of a given landscape to accommodate a specific kind of development? This relates directly to prevailing landscape character and land use. A large grain silo might be expected in a largely arable landscape, but would not be expected in a residential area. An industrial canalside landscape is less susceptible to a proposed new warehouse building than a landscape characterised by educational campus buildings.
These elements require fine judgements to be made, and these judgements can influence the final outcome of the assessment. This is why LVIA has been likened to a ‘Dark Art.’ Inherent in this, of course, is the intimation that the methodology is not, and cannot be, entirely objective. Furthermore, in the final analysis the landscape architect needs to decide whether predicted effects are ‘beneficial’ or ‘adverse.’ One man’s meat is another man’s poison. Progressive modern architecture proposed within a Conservation Area may stimulate and delight some, but there will certainly be others who disagree.
It is important to make sure we protect the best and most valued of our landscapes. Critical planning decisions of course should not be based on subjective, ill-informed or parochial evidence, and ‘landscape’ is usually only one criterion in a wide spectrum of issues under consideration as part of an ‘on-balance’ decision. The LVIA is not a guaranteed level-headed, objective methodology. It is flawed, but it does make us think in a different way about landscape. It encourages us to detach ourselves from our own preconceptions and prejudices, and reflect on what really is important in a landscape, and to whom. If we fail to do this, then we fail to prioritise, and as a consequence we risk protecting mediocre landscapes at the expense of landscapes that really matter.