we've used double glazed windows with external roll down shutters in a double brick house with a 2m high solid brick fence to create a courtyard to screen all but one front window, added a brick garage at the front and also changed all internal and the front door to solid core doors, added wardrobes along the front wall and also added extra sound blocking insulation and there has been a noticeable noise reduction but noise is like water and will leak in and around any gaps including an open back door so the house has to be kept shut tight to minimise street noise from inside