Planning permission - fencing

[Thingsthatgo]

We are hoping to buy a new house in the next few weeks. It’s a corner property, fairly central in town.
The garden runs down the side, and it currently has new fences running down the side which are about 150cm tall.
Historically it has had taller fences, 180cm or more.
My understanding is, that is order to have fencing taller than 90cm, the owners need planning permission, because the fence is next to the pavement. Is that correct? There doesn’t seem to be any permission for the fence, although it has been there for many years.
There is no problem with blocking the view for drivers. Are there any reasons why permission might be denied? Similar properties in the area have high fences.
Our plan would be to add some trellis or similar to make the height up to 180cm.

1m if adjacent to a highway, 2m limit everywhere else. Beyond those limits planning is required. No set definition of 'adjacent' though! Some thinking is that more than 1m away from the highway is enough not to be adjacent...
I'd suggest 1m fence plus a hedge.

Completely agree with Loofah it all does depend on the council's definition of "adjacent" and there have been some cunning ways to thwart a council's view on this on Garden Law before now.

I live on an estate where the corner plots on a road junction have side gardens but the first part of the side garden just abuts the pavement. Once the visibility at the end of the road is enough then they have 2m high fences for half the side garden and what becomes the back garden.

Or they have a very narrow planted area between the 2m high fence and the pavement or none at all depending on which part of the estate you live on and which builder built it.

I would want planning permission in place for the increased height before you proceed. Are there any other examples of a similar property? Did they get planning? Got to love Google street view and an online planning portal.

The back garden begins a fair way down the side of the house, because the front door is to the side as well. There are similar properties with high (2m) fences, and this house has had tall fences in place for many years, at least 10.
We would still want the house if planning was denied, we would go with short fence and hedges or similar. Thank you for your advice. I shall get in touch with planning.