In the context of a certificate of appropriate alternative development, planning need does not need to be expressed as a specific figure.
The Upper Tribunal (Lands Chamber) has considered this issue in Secretary of State for Transport v Quintain City Park Gate Birmingham Ltd and others [2025] UKUT 7 (LC).
The case concerned the entitlement to compensation of the former owners of four neighbouring plots of land at Eastside in central Birmingham. Each plot was acquired by the SST in 2018 for construction of the Curzon Street terminus for the HS2 railway.