A website building system (WBS) includes a layout database to store at least one layout having components and an associated layout signature. It also includes a unit to determine a component set signature for an incoming component set having an existing layout provided by a user, to compare the component set signature with at least one associated layout signature of at least one layout from the database to find a match and to replace the existing layout with one of a selected diverse alternative candidate layout from the database according the match. The layout signature and the component set signature represent a hierarchical composition of the semantic types of the components of the layout and of the incoming component set accordingly. A layout adapter and applier adapts content from the user supplied component set to the selected diverse alternative candidate layout.