Planning Permission signifies that the works comply with the Town & Country Planning Acts which is a requirement for all but the most modest of building works. Some works do not require planning permission, if they fall within the Permitted Development Order.
Building Control refers to Building Regulation approval and this is a separate set of legislation which deals with health & safety issues, building standards and energy efficiency. Almost all building works require building regulation approval but there are, as with most things, some exceptions to that rule.
KMASS can assist in advising you what is required and they have the required skills and expertise to guide you through these processes.