[2005] EWHC 168 (Admin), 7 February 2005. Considers whether the installation of a mezzanine floor for additional retail floor space could reasonably be described as new development within the Town and Country Planning Act 1990 s55 in the context of a planning permission condition that sought to impose an upper limit on non-food retail floor space. Appeal by N to quash the decision of the planning inspector, appointed by SoS, to allow an appeal by L against N's refusal to issue L with a lawful development certificate after N had built the mezzanine without planning permission. "Held": appeal allowed. The condition did not simply limit the amount of floor space that could be submitted for detailed approval. Provided that the total amount of non-retail floor space did not exceed the amount permitted under the planning condition, occupiers could make under s55(2)(a) of the Act any internal alterations they wanted to. A commonsense approach would reasonably describe the creation of extra retail floor space in the form of a mezzanine as new retail development in the context of a planning condition that sought to place an upper limit on non-food retail space.