Injunction?

Hello, I require some assistance. Me and my family decided to go on vacation for 2 weeks, after which we were back home to notice that our neighbours were constructing something on their existing terrace. When we asked them about it, they mentioned they were going to be building 2 more floors above their house. Normally this would have been fine, but in this situation the construction will obstruct the sunlight to our house. It is a naturally dull lit place, but with the construction it will bring in no sunlight at all. We tried to reason with them but they were adamant to finish the building. How can I stop this construction? Can I apply for an injunction or restraining order? Whom do we have to approach? Please do advice us, thank you.