Abstract: Mobile drilling apparatus enables drilling of a plurality of bores in a building wall or the like, concurrently or sequentially or in groups, for the purpose of attaching slabs, panels, siding or other facing material to the wall or for anchoring concrete reinforcement rods to the wall. In the preferred form, the apparatus includes a mobile vehicle having an operator's platform which may be selectively raised or lowered, a vertical drill support frame carried by the platform which may be shifted sidewardly relative to the platform and a plurality of independently driven drills mounted on the support frame by motor driven telescoping structures which travel the drills outward from the frame. The apparatus expedites construction or renovation of buildings by enabling rapid and precise drilling of arrays of bores.