The two joined cases, Crondall Parish Council v Secretary of State and Others (CO/3900/2018) and Canterbury City Council v Secretary of State (CO/3625/2018) are important for four reasons. First Crondall Parish Council was granted Aarhus costs protection by John Howell QC sitting as a deputy High Court Judge in a carefully reasoned judgement. Second Mr Justice Dove applied the approach of the European Court of Justice set out in Case C-323/17 People Over Wind rather than that of the Court of Appeal in Smyth (endorsing the Hart approach), to the relevance of mitigation to screening decisions about appropriate assessment (AA) in relation to Habitats and Birds Directive special protection sites. Third the same principle may well apply to screening decisions about EIA. Fourth the judge emphasised that the exercise of Champion discretion not to quash for justiciable errors did not permit courts to make their own planning judgements or strike new planning balances.
The two cases were heard together as they had in common a similar error of law related to the question of whether or not an AA had been undertaken of the effects of residential development upon nearby Special Protection Areas (SPAs) in accordance with the Habitats Directive.
Mr Justice Dove’s judgment is one of the first to consider the implications of the Court of Justice Case C-323/17 People Over Wind to development in the UK.
The Crondall Parish Council case concerned residential development of 30 houses which was granted permission on appeal at Broden Stables in Farnham within Hart District. The site was located outside of the settlement boundary for Crondall and there was a resulting conflict with settlement boundary policies in the adopted and emerging local plan.
The Habitats Directive was relevant because the development site was within the “zone of influence” of the Thames Basin Heaths SPA. Consequently, the Interim Avoidance Strategy required the developer to make contributions to a SANG (suitable alternative natural greenspace) and SAMM (strategic access management and monitoring) to mitigate against the potential for residents of the scheme, in combination with residents of other schemes, causing disturbance and deterioration to the SPA. The developer had agreed to pay defined contributions towards a particular SANG and SAMM prior to applying for planning permission.
The Parish Council challenged the decision of the Inspector not to subject the proposals to an AA of potential effects under Article 6(3) of the Habitats Directive. The Secretary of State eventually conceded that the Inspector had unlawfully screened out an AA on the basis of mitigation measures, namely the SANG and SAMM contributions. That was not lawful following the decision of the Court of Justice in Case C-323/17 People Over Wind. That case decided that "it is not appropriate, at the screening stage, to take account of the measures intended to avoid or reduce the harmful effects of the plan or project on the site." The Secretary of State nonetheless invited the Court to exercise its discretion to not quash the planning permissions in both cases (relying on Walton v Scottish Ministers  PTSR 51 and Champion  1 WLR 3710) on the basis that it should conclude on the facts that the decisions would not have been any different had the error not been made.
The Judge allowed the claim on the basis of ground 1 and ordered that the permission be quashed.
When considering the discretion to not quash, the Judge held that it was essential he should take “a careful and fact-sensitive examination of the available evidence”. On the evidence in the Crondall Parish Council case, there were two key reasons why the Judge refused to exercise his discretion not to quash.
First, the Court was effectively being invited to re-strike the planning balance reached by the inspector which would involve the making of a planning judgement which was not a task which courts should seek to undertake (see ).
Second, the Judge accepted at  the Parish Council’s submission that there were “loose threads” in the analysis of potential significant effects on the SPA, preventing him from concluding that the decision might have been different had an AA been undertaken.
By contrast, the Judge did exercise his discretion not to quash in the Canterbury City Council case because he was satisfied in that case that the error did not make a difference to the outcome.