The construction sector consumes high amounts of resources and energy while generating significant amounts of waste. This development is contrary to Circular Economy principles, which require buildings that are resource and energy efficient and enable material recycling to the greatest possible extent. To effectively tackle this problem, the EU places a strong focus on sustainable building design. However, to assess this development, indicators that measure the potential recyclability of buildings already at the design stage are necessary. In this study, the “Relative product-inherent recyclability” (RPR) assessment method is applied to evaluate the recyclability of buildings. The RPR method considers buildings’ material composition and structure (assembly) to measure recyclability, thereby describing recycling-relevant factors. The method is based on the statistical entropy approach, which aims to describe material distributions. The RPR increases the more building parts can be disassembled, allowing recovery of concentrated materials. A case study on a timber and concrete building is used to demonstrate the applicability of the RPR metric. The results show that the RPR metric is a suitable indicator for expressing buildings’ inherent recyclability, thus identifying significant differences between building variants. Relevant design optimizations can be deduced from the RPR results. In our case, the timber building achieves higher recyclability than the concrete building. Applying the RPR indicator on the EU level can be recommended and offers significant insights into the design and recyclability of buildings. Architects and constructors could use the metric as a planning and evaluation tool, thereby promoting circular building design concepts.