The judge also concluded that the inspector had failed to identify exceptional circumstances to justify modifying the green belt.
Gallagher Estates Limited and Lioncourt Homes Limited had jointly challenged the Solihull Local Plan, which was adopted in December 2013 following examination and publication of the inspector's report. Both developers had proposed residential developments on sites which were placed within the green belt in the Plan.
The judge said that the full housing need required in Solihull had not been objectively assessed, as is required by policy. "When the report is read as a whole, far from full objectively assessed housing need being a driver in terms of the housing requirement target, as the NPPF requires, it is at best a back-seat passenger," the judge said.
The judge also said that the approach taken by the inspector in relation to green belt boundaries was wrong in law, as far as they concerned the developers' two sites. "The inspector, unfortunately, did not adopt the correct approach to the proposed revision of the green belt boundary to include the sites," he said.
The judge said the inspector "performed an exercise of simply balancing the various current policy factors, and, using his planning judgement, concluding that it was unlikely that either of these two sites would, under current policies, likely to be found suitable for development".
"That, in his judgment, may now be so, but that falls very far short of the stringent test for exceptional circumstances that any revision of the Green Belt boundary must satisfy," the judge said.
Christopher Lockhart-Mummery QC of Landmark Chambers and Pinsent Masons acted for the developers in the case.
The Court will hear further submissions on the relief being sought.