Today, 19th and 20th c. modern period buildings are the trademark of numerous European cities, forming a great part of EU Built Heritage, reflecting and shaping the identity of our local, national and multinational societies. Considering that historic buildings are ineffective in terms of energy consumption for heating and cooling, among the biggest restoration and renovation challenges is to enhance the energy performance of historic buildings. SINCERE aims to elucidate the values of Built Heritage and provide the tools for optimizing the carbon footprint and energy performance of historic buildings, towards the requirements of net-zero-carbon-buildings, by utilizing innovative, sustainable, and cost-effective restoration materials and practices, energy harvesting technologies, ICT tools and socially innovative approaches. SINCERE adapts a multi-scale concept, from material-, to building-, to neighbourhood- to city-scale, applied on the three main parts of buildings: structure, external envelope (opaque), and transparent parts, implemented at different time-frames, in order to provide decision making tools to the stakeholders involved in the process, considering the full-service life of the buildings, including restoration, operation, monitoring and maintenance phases. Energy performance in terms of retrofitting materials and solutions will be optimized according to the buildings’ unique structural, architectural, functional and materials characteristics, their environmental setup, as well as local future climate change scenarios. SINCERE will provide a palette portfolio of sustainable restoration options that will be evaluated by H-BIM/H-DT tools in order to enable the selection of optimum solutions and the planning of necessary adaptation actions. SINCERE will also focus on raising awareness and empowering Europeans to promote the concept of preservation CH buildings by disseminating the obtained results through national and international scale activities.