Ask a real estate pro: Not all good fences make good neighbors

If you give in and agree to contribute to the installation, you may also have to help maintain it later. You and your neighbor should write down your agreement so that there are no misunderstandings later. Of course, if you do not agree there will be nothing to write down. You do not need a contract to say you are not participating, but if you want to be safe, you can send him an email or letter so there is no question of your intentions later.