Seems to be what I can see online that it's ok if it's under 2.5 metres tall if it's within 2 metres of a boundary.
Detached house but attached gardens, it would be within 2m of our boundary with our neighbours to one side. The other side of the fence from our garden however has their garage and a parking space before their garden so not directly next to their social area if that makes sense. Anyway the height is 2.6 metres.. 2.59 to be precise? The platform height is 120cm, just the very tip of the roof is what reaches 260cm. Toddler wouldn't be able to see in their garden for a couple of years yet.
Would that be ok? I don't think our neighbours would complain.. but just in case I want to make sure before we have it installed.