Many thanks for your replies.
I had thought to run the lights from the Main building but it would seem the only option would be some sort of flood light. I really wanted some sort of secondary lighting to create a subtle mood. The plans and build that have been passed by the building...
Can you help?
I am building a flat roof single storey extension with roof garden on top.
The flat roof will be clad in roofing felt covered in concrete tiles. The roof garden in contained by metal railings. My problem is that I need to light the area. I don't want to drill through the new flat...