Improving productivity has been a longstanding challenge for the UK Construction Industry and has increasingly become a focus of the UK Government. Constructability is a specific term used to describe how efficiently a design can be realised in construction, thus improving productivity. While this term has been used for many years, it remains a consistent challenge for the construction industry to address. This exploratory research addressed the question: what is the current practice for the incorporation of constructability in design within UK construction industry design firms? The aim is to establish what is currently done in practice, identifying changes needed to enable the industry to transform and meet the challenges of the twenty-first century. This paper will describe a research investigation that included 20 structured interviews with current designers in senior roles, representing 10 organisations within the UK construction industry. Qualitative data was collected and thematically analysed, showing that while the industry has embraced the importance of constructability, it is rare for a formal policy or process to be used by designers. Designers generally consider constructability only through their tacit knowledge whilst making subjective decisions, not data-driven decisions. Furthermore, UK designers associate constructability with the Construction (Design and Management) (CDM) Regulations which are focused on health and safety; this is perhaps not the best vehicle for incorporating constructability. The findings of this study have provided an insight into the current practices of UK construction industry design firms, suggesting avenues for future improvement.