The developmental process pertaining to the initial formation of a renal capsule from unspecified parts. The renal capsule is the tough fibrous layer surrounding the kidney, covered in a thick layer of perinephric adipose tissue. It provides some protection from trauma and damage. During development, it comprises a single layer of flattened cells that lie just above the cortical stroma and the condensed mesenchyme of the nephrogenic zone. It is in this region that the early stages of nephron induction and formation of new generations ureteric bud branches occur, as the kidney expands. [ GOC:mtg_kidney_jan10 ]