23rd February 2023
With the last notable case concerning minor material amendments to existing planning consents being almost three years ago , this recent Planning Court judgment casts further light, or possibly shade, upon variations to existing planning consents. The decision comes at a time when many in the development industry are still reeling from the impact of Hillside . Armstrong v Secretary of State  will be of interest, if not surprise, to developers and decision-makers alike for its conclusion that section 73 of the Town and Country Planning Act 1990 (TCPA 1990) is not limited to ‘minor material’ or non-fundamental amendments to planning consents.
Armstrong has provided further judicial authority upon the scope of section 73 TCPA 1990 applications to develop land without compliance with conditions attached to an extant planning permission. The Planning Court held that the limits of section 73 are not set by the question of whether there would be ‘minor material amendments’ or amendments which do not involve ‘substantial’ or ‘fundamental’ variations to the approved scheme.
Previous authorities  confirmed that different conditions may be imposed under section 73 if they do not amount to a fundamental alteration of the original application when considered in light of the original consent as a whole and which may not be at odds with the description of development.
Armstrong has highlighted that there is nothing in statute or case law preventing applications the decision-maker considers to be more than a ‘minor material variation’ or a fundamental variation. Legislation does not restrict the scope of section 73 to ‘minor material amendments’ even though it is common to refer to an application as such. Armstrong clarifies that the terms of the section itself are not limited in such a way and place no restriction on the magnitude of the changes that can be sought. Applications to vary existing planning consents should therefore be considered on their planning merits, not whether they fall within the scope of section 73.
The Council granted full planning permission in 2007 for the construction of a single dwelling. None of the conditions referred to any approved drawings or plans. The permission was implemented by minor works and, in 2020, the Council inserted a tenth condition which required development in accordance with the plans then listed in that condition.
An application under section 73 TCPA 1990 followed in 2021. It sought to vary the approved scheme by substituting the drawings listed in the condition. The new plans showed the proposed dwelling in a different design, style and form. The Council refused this application as the proposed amendment would completely alter the nature of the development and differed materially from the approved permission. The Council considered that this went beyond the scope of section 73.
The refusal was appealed to the Secretary of State. It was contended by the appellant that although:
The appeal was dismissed. The Secretary of State considered the variation to be substantially different to the original permission and beyond the parameters of ‘minor material amendments’, regardless of the fact it would not conflict with the description of the development permitted.
This decision was then challenged in the Planning Court – a specialist division of the High Court. The Planning Court found that the planning inspector had unlawfully rejected the application under section 73. It held that:
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For further advice or information on the Armstrong v Secretary of State case and variations to existing planning consents, or for tailored advice in connection with any development projects or planning proposals or concerns more generally, please contact Victoria Leam or any member of the Planning & Environment team.
 Finney v Welsh Ministers  EWCA Civ 1868
 Hillside Parks Ltd v Snowdonia National Park Authority  UKSC 30
 Armstrong v Secretary of State for Levelling-Up, Housing and Communities  EWHC 176 (Admin)
 Arrowcroft  PLCR 7, Finney  EWCA Civ 1868, Vue  EWHC 588 (Admin)