Posted: 29/03/2015 at 12:31
Can you post a photo as it's very difficult to assess the situation?
Without that, and guessing that you mean privacy from inside your house, my advice would be to plant something a bit nearer to you in the same direction as the gap as seen from the problem window. If you plant something too near the gap, it may restrict the light to the new privet plants and they would take longer to grow. Perhaps a piece of trellis or an obelisk with a clematis growing up it. If you choose a Group 3 clematis like Hagley Hybrid and get one in a 3 litre pot, it will romp away and be 6ft high in a couple of months. If you want instant, then maybe a large pot of bamboo (and I would keep it in the pot as many are invasive.)