In the UK, the height of a garden fence cannot be higher than 2 metres unless you have permitted to do otherwise. Erecting a high fence can be perceived negatively by neighbours; however, a trellis topper is ideal if you want to add some heights to your garden fence. The maximum height of a trellis topper should 2 metres above the ordinary fence. If your fence exceeds the maximum height, you will have to apply for a planning permission.
