Decking and drainage

The cheapest option to start with is to approach the local-authority. Report your neighbour to the Planning Department - as the neighbour may be in beach of planning - Building Control as they would not have allowed the drainage, and Environmental Health with regards to the flood. If none of these may help, then it becomes legal and expensive. A Building Surveyor would help you get a resolution to your problem.

Speak to the local authority as he is not allowed to divert water into your garden.

No they are definitely not aloud to drain water into your property. I would start off by approaching the neighbour to see if you can resolve the problem between both of you. If that fails I would go to local authorities to deal with it.

The first thing to do would be to speak to the neighbour. Be polite as what you are reporting is reasonable and the neighbour may not even be aware.. In most cases any damage to your property caused by this your neighbour would be liable for, however I suggest you try to resolve it peacefully without going straight to any authorities! If the structure was erected by a tradesperson they may have overlooked the issue, either that or they just wanted to take the money, this is also common! Either way, your neighbours may realise that this isn't acceptable and either get someone to rectify it or you could call someone yourself.. Personally if I turned up to your house and identified the problem I would knock the door Personally and explain the situation to the neighbours in a way they could understand. I would also think of a solution and offer them a quote. This wouldn't cost you anything and it would likely get me a job! I realise not every trades person may be this competent, nor have the sales experience I have but give it a try! Find someone reputable with half a brain and you should resolve this issue amicably. Regards, Steff.