Buildings are the dominant end users of energy, as well as the largest contributors to CO2 emissions due to fossil fuels. As an investment, buildings possess the slowest turnover of the capital stock, but also comprise the greatest majority of any country’s capital assets. Energy efficiency is thus extremely important in buildings, since it can offer expanding instead of diminishing returns, rendering the adoption of novel technologies imperative for the building & construction (B&C) industry. This conclusion is further reinforced by the EU energy strategy for 2020, 2030 and 2030 , where de-carbonization of buildings is prominently featured . To achieve these targets, the Zero Energy Building (ZEB) and near-ZEB (nZEB) market share in construction and refurbishment needs to significantly increase: in refurbishment, specifically, an increase by a factor of two to three times of the current rate of between 1.2% and 1.4% in the decades up to 2050 is required. The EU B&C sector comprises 53,280 companies and 12,730,700 employees , over 80% of which are SMEs and micro SMEs. Policy changes face therefore reluctant acceptance in the fragmented and conservative B&C landscape, in addition to the adoption of new technologies that are similarly problematic. The state of fragmentation makes offering holistic solutions for deep renovation difficult, especially at an acceptable cost and quality, since the process involves input from multiple separated disciplines without the benefit of involvement of all the stake-holders at the planning stage of the renovation, resulting in additional costs and a heightened risk of failure. The renovation market is principally supply driven which can lead to a mismatch between the offered products and the end-user’s needs. Many customers prefer to maintain high building operating costs and a suboptimal indoor environment to the time-consuming, disruptive and risky renovation process. On the other hand, Indoor Environment Quality (IEQ) is becoming exceedingly critical in modern construction. While it is relatively straightforward to construct a new building with measures achieving a constant and satisfactory IEQ, renovation of existing buildings constructed in the 50s-70s is especially challenging when the IEQ factor is considered. Nevertheless, IEQ is critical to modern society: poor IEQ has adverse effects not only in workplaces, but also at home, causing health issues and affecting school children homework, home/office working and on sleep quality distressing productivity during the next day. In fact, the total calculated burden of disease attributable to Indoor Air Quality (IAQ) in EU-26 [EU-27 minus Malta] is ca. 2 million DALYs per year, i.e. two million years of healthy life is lost annually ”. The RECO2ST project is positioned to address these issues, through coverage of the entire refurbishment supply chain and encompassing all the stages, from planning and decision making to installation, operation and monitoring. The project will enable the formulation of customized and efficient renovation action plans and implement cost efficient technological solutions improving the energy efficiency of residential buildings into nZEB levels, through reductions of 60-95% in energy consumption. Finally, the buildings renovated through RECO2ST will achieve the optimal conditions of indoor environment, improving the living conditions of the inhabitants, and increasing building value for the owners. To guarantee achieving these benefits, strategic objectives have been identified, along with the sets of corresponding KPIs against which the success of the project will be defended.