He is seeing intuitively there is an energetic gateway to energetic grid lines of energy that allow spirit traffic to take place. This has multiple purposes but is the avenue enabling spirits to travel distances more efficiently than through conscious will. The buildings in question have spirit portals and so this is what he is perceiving, the portals connecting to these energetic grids and that they are infested with many troubled beings. So what is in order here is a location clearing with your Protocol. This will also improve the energy felt by humans entering these locations. As you know, there are many who sense darkness intuitively without understanding its origin or nature and will simply find a location unappealing. So this is a headwind for a developer to take a leap of faith in a property and invest money on its improvement. Such buildings are often subjected to demolition and this can be wasteful because the problem is not the building itself but the energy of the location, which will not change by removing the physical building in that spot. So a clearing will help clarify things for all humans encountering these buildings, and any plans they might develop to make them useful again or rescue the property for the underlying value.