In this article, we highlight the potential of nanocelluloses, such as cellulose nanocrystals (CNC) and microfibrillated cellulose (MFC), to serve as building blocks for the design of hierarchical functional nanomaterials. Four categories of value-added nanomaterials are envisaged here, namely aerogels, emulsions, templated materials and stimuli-responsive nanodevices. But most importantly, we demonstrate that appropriate functionalization methods are required in order to tailor the nanocellulose surface and further design materials with required characteristics.