In the early stages of building renovation projects, the lack of information on the existing building and an unclear definition of project objectives have been identified as critical bottlenecks. An early decision support tool has been developed to mitigate or overcome these barriers. The tool provides initial estimates tailored to the specific building and climate being assessed, and can be used to guide the renovation design at an early stage, even from very limited information. It includes the automatic generation of potential renovation scenarios, a dynamic energy simulation of existing and renovated cases, integrated economic and environmental assessments from a life cycle perspective, and a multicriteria analysis that ranks renovation alternatives to meet the interests of the stakeholders involved. The user obtains an initial indicative budget and the expected potential benefits of several renovation projects over comfort, energy consumption, economic cost and environmental performance. One of the main assets of the tool is the reduction in time and cost at initial phases of the renovation process, avoiding the need of site visits and the use of more laborious simulation tools.

The renovation of buildings has a high capacity to influence the environmental impacts and global objectives of climate change mitigation. In the context of designing low-energy buildings with minimized environmental impacts, the life cycle assessment (LCA) has been proven a straightforward method, to evaluate the direct and indirect environmental impacts of a building concept. Even though it is the most energy-intensive element, the use phase is not only a source of environmental concern but also the whole life cycle of the building and its components. However, energy-efficient renovation decisions tend to be financially motivated events, subject to exogenous constraints or barriers, that do not integrate whole life cycle thinking. This study aims to identify how the LCA information can be considered in comparing renovation options. compare renovation options, taking into account the modular envelope system developed as part of the European research project ENSNARE (ENvelope meSh aNd digitAl framework for building Renovation) case study. The study analysed different renovation scenarios, generated according to combinations of renewable energy sources and compare them to the base case and typical renovation scenario. Such information can support the design team in making decisions that consider the whole building and its components' life cycles.