There's a good summary of the law on outbuildings and the legal shed height here. the government planning portal has the definative answer on what they term as outbuildings but not always in everyday terms, and remember the local council planning officers are at the end of the phone for advice.. Therefore the height of the shed would be measured from the highest ground level adjacent to it. if the height of the shed exceeds 2.5 metres above ground level then planning permission will be required. at this stage it will be assessed whether or not the height of the shed is a problem (amongst other considerations).. Maximum shed height post by littlehorse