Raised bed against neigbours wall

[AndrewFG]

My house is an end of terrace house, and there a gap of about 4.5m between our gable wall and the gable wall of the next terrace.

This gap of about 4.5m X 5m belongs to me. And we want to convert it into a courtyard garden with French windows on our house, and raised beds on the other three sides.

My question is concerning the raised bed on our neighbours gable wall. Specifically how to avoid drainage or damp problems for the neighbour.

I think we cannot pile the raised bed directly against the neighbours wall? Particularly not if it is above their Damp Proof Course?

And I think that even covering the neighbours wall with a pond liner membrane is probably also not allowed? Because their bricks would not be able to breathe?

Are my assumptions above correct?

So I think I need to build a separate retaining wall for the back of our raised beds with its back separated from the neighbours wall. Is there any guidelines concerning how to build that raised bed back wall, and if it should have a water proof liner (I suppose yes), and what is the minimum recommended distance between the two walls (the courtyard is quite narrow so I want to keep the gap as small as possible).

PS I was thinking something like this..

http://www.whitebear.ch/downloads/raisedbed.png

[Tony McC]

That's fine - leave a minimum of 100mm between neighbour's wall and your raised structure, and that will be adequate.

Make sure that there is no danger of any surface water becoming trapped in there.

[AndrewFG]

Ok. Many thanks.

[AndrewFG]

PS I updated my design to include Tony's suggestions..

http://www.whitebear.ch/downloads/raisedbed.png

[Tony McC]

Lovely!