The appellant proposed to moor paired motorised barges on the downstream side of the weir for part of the year to generate hydroelectricity, which would be stored in batteries on the vessels. Thereafter, the barges would be navigated, using their own propulsion, to riverside destinations where they would be moored and used to transfer power to customers.
The council had determined that the proposal comprised development on the basis that mooring the barges would amount to a building operation. Its view was based on Cardiff Rating Authority v Guest Keen Baldwin  and the Court of Appeal ruling in Skerritts of Nottingham v SSETR , which identified three primary criteria – whether a structure would be of a size that would normally be constructed on-site rather than being brought in ready-made, whether it would cause a physical change of some permanence and whether it would be physically attached to the ground.
With regard to size, the council argued that the paired barges would be substantial, having an area of 200 square metres, and the cabins would appear as buildings sitting on top of what appeared to be a pontoon. While agreeing that the barges’ size would be significant, the inspector found that they would not be dissimilar to narrowboats and other barges in terms of length and width or cruise boats and houseboats in terms of height. They would arrive at the weir completely formed and under their own propulsion and would not therefore be constructed on-site, she reasoned. Equally, she held, they would appear much smaller than the weir structure.
As the barges could be regularly moored at the weir for up to six weeks at a time, the inspector considered that they could be regarded as a building or building operation, having regard to the appellant’s intentions and the significance of their presence. With regard to physical attachment, she held that the clamp and hawser method proposed would not change the condition, state or quality of the weir and the barges could easily be removed by one crew member without any power tools. On the balance of probabilities, she concluded that the proposal was not a building or building operation and granted a lawful development certificate.
Inspector: Diane Fleming: Written representations