The SmartBuilt4EU project has set up four task forces investigating issues related to smart buildings: their objective is to identify the remaining challenges and barriers to smart building deployment, and the associated research and innovation gaps that should be addressed in the near future. Task force 3 investigates how smart buildings can interact at best with their external environment. The topic investigated in year 2022 addressed smart building as enabler of new energy practices and communities with a focus on the grid-interacted, consumer-engaging building. This White paper focuses therefore on the following questions: Buildings and energy efficiency: how can the building facilitate or foster the development of new energy practices in electricity and heat? Buildings and energy communities: beyond the single building scale, which smartness requirements act as enablers of energy communities? In its first part, after a reminder of terminology on active consumers and prosumers, the paper provides a state-of-the-art regarding the contribution of Electricity Directives to new customer-centric energy practices and new communities as well as the contribution of EPBD to the definitions; The literature review focuses on energy communities as novel entrants in the energy value chain, on the ‘smart built environment readiness’ framework with regard to new energy efficiency practices and electromobility. Finally, the interaction between electromobility and buildings is presented around the perspective of the new ‘Right to plug’ requirement as a trigger for home charging roll-out. Specific attention was paid to a selection of EC-funded projects REACT, SPHERE, BIM4RE, PHOENIX, MERLON while a set of other related initiatives are listed. A brainstorming process enabled to identify some key barriers and drivers regarding Smart building as enabler of new energy practices and communities. Based on the State of the Art and the barriers and drivers, a number of research and innovation gaps were identified including: R&D, Demo, regulation & legal framework, certification & standardisation and scaling up & industrialisation. The gaps will feed the elaboration of the Strategic Research and Innovation Agenda on smart building, together with some recommendations targeting policymakers.