Just to further clarify, Council does NOT approve permits, they approve land use. Council does not decide on the detailed designs of the buildings, that is left to Administration / CPC.
When a DP is approved, it is given the status of "Pending Release", which means the design has been approved, but there are conditions that need to be met that won't change the design. For instance, cost obligations for off-site utility work, or sometimes minor changes to some features of the building (but nothing that will substantially change the building design). A developer needs to satisfy all of these conditions to get the permit "released", which will then allow construction. As Mountain Man stated, it is pretty rare to get a BP approved without a released DP.