Mortell, R (on the application of) v Oldham Metropolitan Borough

When screening Schedule 2 development for environmental impact assessment purposes, a local planning authority must consider every relevant Schedule 3 selection criterion. A comparison between existing and proposed end uses is insufficient where the development involves multiple sites, substantial demolition, possible contamination or effects on architectural heritage. Cumulative effects, construction-phase energy use, natural resources, waste, contamination and heritage may all require consideration. The court must not decide whether significant environmental effects are likely or substitute its own assessment for that of the authority. It must quash the permission where the authority failed to address relevant considerations.

The claimant sought judicial review of three outline planning permissions granted by Oldham Metropolitan Borough Council for residential development at sites within the Derker area. The permissions formed part of a Housing Market Renewal Pathfinder programme and supported a compulsory purchase order.

The Council had adopted screening opinions under the Town and Country Planning (Environmental Impact Assessment) (England and Wales) Regulations 1999, concluding that no environmental impact assessment was required. The claimant alleged that the Council had failed to consider cumulative effects, construction-phase impacts, contamination and architectural heritage. A separate issue concerned the timing of assessment for outline permissions following R v London Borough of Bromley, ex parte Barker [2006] UKHL 52. The court decided the first group of issues and therefore did not determine the second.

The claim succeeded. The three screening opinions were invalid and the outline planning permissions were quashed. The claimant was awarded costs, subject to assessment if not agreed.

1. Relevant considerations. Under Regulation 4(5) of the Town and Country Planning (Environmental Impact Assessment) (England and Wales) Regulations 1999, the authority had to take into account such relevant selection criteria in Schedule 3 as applied to the development. The authority was aware that the three sites formed part of the same Masterplan, but it did not consider their cumulative effect. Cumulative effects might have a magnitude and significance which the individual effects did not possess.
2. The authority also failed to consider construction-phase effects, including energy consumption, natural resources and waste. The substantial demolition proposed made those matters plainly relevant. The fact that the precise energy balance might depend on reserved matters did not remove the need to consider the issue at screening stage.
3. Possible contamination was relevant because the sites were near a closed landfill site and the permissions required investigations into landfill gas and land contamination. The impossibility of conducting a full investigation at screening stage did not justify disregarding the issue altogether.
4. Architectural heritage was also relevant. The extent of proposed demolition could have significant environmental effects, notwithstanding that heritage appeared in Schedule 4 rather than Schedule 3 and a later condition required consideration of demolition and retention.
5. The court would not determine whether those matters were likely to produce significant environmental effects. That assessment belonged to the Council. The court’s function was to ensure that the Council had considered the relevant matters. It had not done so, and the permissions therefore had to be quashed.
6. Obiter, in light of R v London Borough of Bromley, ex parte Barker [2006] UKHL 52, any fresh outline permission should contain conditions keeping the development within the parameters assessed at screening stage. Effects should be assessed at the earliest possible opportunity. Only effects not identifiable, overlooked or unanticipated at outline stage could properly be left to reserved matters.