A method of manufacturing a structure, the method comprising: forming a panel assembly by bonding a stack of thickness control plies of composite material to a laminar composite panel, the stack of thickness control plies having a first edge proximate an edge of the laminar composite panel, a second edge opposite the first edge, and a ramp where the thickness of the stack of thickness control plies decreases towards the first or second edge; measuring the thickness of the laminate composite panel or the panel assembly; controlling the number of thickness control plies in accordance with the measured thickness; attaching a first component to the panel assembly, the first component having a surface which engages the laminar composite panel and a ramp which engages the ramp in the stack of thickness control plies; and attaching the laminar composite panel at or near its edge to a further component.