DD – it’s certainly possible, but Councils don’t usually permit it unless the structure is properly supported by foundations that are placed outside the zone of influence.
So what does that mean?
Well…. it means that the foundations of any structure need to be placed such that the weight of the structure and whatever’s within it doesn’t damage whatever pipes are below and within the easement, and so that it everything won’t collapse into an excavated trench if pipes are at some later time placed within that easement.
Frankly though, most Council’s wouldn’t be concerned about a garden shed or similar pre-fabricated structure on a concrete slab, as the gross weight would be unlikely to create a significant load on anything below, and if excavation was necessary the structure could be easily be dismantled.