How close you can install an outdoor fireplace to your boundary will differ country by country and region by region. For example, in New Zealand, you are unable to build any structure, including an outdoor fireplace directly on your neighbours boundary, without their permission. In this example, if you need to install an outdoor fire near their boundary, allow a gap, from the back of your fireplace to your boundary, of 1.5 metres. But please note — the responsibility for assessing the rules for your region, and/or checking with your neighbour, lies with you.
Wind direction and smoke
If your predominant wind would blow smoke towards you neighbour – some consideration is needed. This might be an opportunity for a discussion with your neighbour — but to avoid producing too much smoke, start your fire with small pieces of dry wood, then slowly add more. This will significantly reduce how much smoke you create.