Parameters within EIA

Jenny Ray from Spawforth discusses the use of parameters in outline planning permission applications for developments that are subject to environmental impact assessment (EIA)

The context for the use of parameters in EIA has come about by way of a number of court cases relating to outline planning applications, in particular, R v Rochdale MBC ex parte Tew (1999) and R v Rochdale MBC ex parte Milne (2001), which are known as the “Rochdale cases”.

In the first case, the courts quashed planning permission for a business park as it was considered that there was not enough information submitted to identify the likely environmental impacts. The second application was also taken through the High Court, where it was found that enough information was submitted, and the conditions of the planning permission tied the development to a masterplan and limited the consent to certain activities and buildings.

Outline planning applications reserve a series of details for consideration at a later date with indicative details being submitted to show how a site could be developed. The Rochdale cases have provided clarity on the level of information required for an outline planning application for EIA development to ensure it complies with the EIA Regulations and EU Directive and have evolved the approach known as the “Rochdale Envelope”.

The Rochdale Envelope uses a number of parameters to define the project description. A parameter is a fixed part of the proposed scheme that cannot change and to which subsequent reserved matters submissions will adhere to.

The parameters need to be a series of worst case, but realistic, details that capture sufficient detail of the proposals to allow the environmental impacts to be identified. They can still, however, enable an element of flexibility for developers, without being too broad or too flexible so as not undermine the accuracy and robustness of the EIA. As such, where a value or quantity is relevant, they are often identified as maximums or a range showing the minimum and maximum values.

The parameters will be conditioned as part of the outline planning permission to keep the development within the parameters assessed and to help prevent the need for further assessment or updates to the environmental statement (ES) at a later date. Indicative details can still be submitted, but these are for information.

It is, therefore, the parameters of the proposals that are assessed in the ES to understand the significance of the likely environmental impacts. The parameters will evolve during the evolution of the proposals and are usually influenced through consultations with the local authority, stakeholders and the community.

Mitigation that is required to address potential environmental impacts can also be incorporated as a parameter. The parameters will therefore need to be fixed at an agreed point in time when the scheme is determined to allow final testing of the proposals for the environmental assessment.

Parameters differ from constraints which are existing features on a site that need to be taken into account when preparing the masterplan and may include pylons and water courses, for example. A parameter will be what needs to be considered as a result of the constraint, such as the standoff that is required around a pylon or gas main.

Parameters also differ from design principles which are the overarching themes from which the design parameters and masterplan evolves. These are concepts such as access points and movement through the site. These can, however, develop into a parameter should they form a fixed part of the proposals.

Spawforths has developed a series of approaches to record the evolving parameters of a scheme and the reasons for these parameters. The recording method is a schedule that is accompanied by a plan. The plan identifies the parameters graphically and spatially, and forms the basis of the EIA to which the planning permission will be tied.

Case law has shown that, as a minimum, details relating to the design and size or scale of a project are to be included in the application. The range of parameters will vary from project to project, but will typically include a range of the following elements:

  • Access point and/fixed routes
  • Proposed land use(s)
  • Number of units /square footage
  • Footprint
  • Finished floor levels/ground levels
  • Building heights
  • Boundary treatment
  • Landscape proposals
  • Proposed drainage features
  • Noise mitigation
  • Standoff distances from constraints
  • Any key design parameters

Care needs to be taken when considering the Town and Country Planning (Development Management Procedure) (England) (Amendment no.3) Order 2012which came into force on 31 January 2013 . This Order removed the existing national requirement for information on scheme layout and scale for outline planning applications, where these details are to be submitted as reserved matters at a later date. However, there is still a need for the relevance of this information to be considered for EIA development at the outline planning application stage.

This article was written as a contribution to the EIA Quality Mark’s commitment to improving EIA practice.

Jenny Ray is a principal planner at Spawforths [email protected]

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