The construction sector consumes 40% of resources globally and produces 40% of global waste and 33% of all emissions. Considering the projected global population growth of 9.6 billion by 2050 and the resulting increase in the use of materials in the built environment, a different approach will be necessary to construct, maintain, and renovate future buildings. The transition from a linear economy to a circular economy (CE) has the potential to reduce resource use, environmental impacts, and waste in the built environment. Creating a circular economy in the built environment is therefore of fundamental importance to achieve a sustainable society. Through the application of a systemic approach that considers the building as a set of technological subsystems (e.g., vertical closures, roof, furniture), components (e.g., infill panels), and materials, this paper—starting from a review of the literature on the topic of the circular economy applied to construction—establishes a framework of circular design strategies and definitions that links the VRP framework, based on the R-imperatives, to the Design-for-X strategies (DfX). The first research objective was to develop a design tool for circular building components and technological subsystems.