It is advisable that you seek advice from your local authority if you are planning to install new gates, as there may be certain restrictions in place. You will most likely not need planning permission if your gate will open onto a private road, and is no taller than two metres high. However, if your gate opens onto a public road, or a public footpath, it must not exceed 1 metre tall, otherwise you must apply for planning permission. It is unlikely that you will need to seek planning permission if you are simply installing an automation system on existing gates. Similarly, if you are replacing an existing gate with a new gate of a similar size, you will generally not need any planning permission to do so.