I have a 6.0" fence, but the neighbour behind has now had a conservatory built but as their property is higher than ours this is towering above it. As the fence is the actual boundary/hedge, I now wish to plant something substantially higher than the fence to provide some privacy. Any suggestions
Legally you can only have a fence/hedge 2 metres high without planning permission.
If you want something taller, I'd suggest you phone your local council's planning department for advice as the planning regs vary from area to area.
You could plant trees/shrubs that are taller than 2 metres as long as they do not form a continuous barrier (i.e. a hedge).