The hole is nearly dug for my trench fill foundations. Is there anything I need to do before the concrete gets poured? I'm planning to get power and water to my workshop at the end of the garden at some point in the future, which will come from the extension. Will these go through the wall above ground then underground or is it worth putting some conduit in? There will be a drain against this wall for the new kitchen sink. Anything else worth doing/considering?