# Hurdles to a Circular Built Environment: A Look at the Economic and Market Barriers
## 3 Results
\begin{table}
\begin{tabular}{c c c c c} \hline \hline
**Pair** & **Chi2** & **\(p\)-Value** & **Degrees of Freedom** & **Adjusted \(p\)-Value** & **Significant** \\ \hline Engineers vs. Public Sector & 3.497866 & 0.478203 & 4 & 10.04226 & FALSE \\ Engineers vs. Academia & 8.164707 & 0.085728 & 4 & 1.800282 & FALSE \\ Engineers vs. Project Managers & 3.445807 & 0.486166 & 4 & 10.20949 & FALSE \\ Engineers vs. Architect & 1.744512 & 0.782617 & 4 & 16.43496 & FALSE \\ Engineers vs. Business & 3.263422 & 0.514748 & 4 & 10.80972 & FALSE \\ Engineers vs. Others & 2.486771 & 0.647006 & 4 & 13.58713 & FALSE \\ Public Sector vs. Academia & 3.320803 & 0.505643 & 4 & 10.6185 & FALSE \\ Public Sector vs. Project Managers & 2.29568 & 0.681556 & 4 & 14.31267 & FALSE \\ Public Sector vs. Architect & 3.643282 & 0.454629 & 4 & 9.858006 & FALSE \\ Public Sector vs. Business & 1.132429 & 0.880993 & 4 & 18.67096 & FALSE \\ Public Sector vs. Others & 1.585002 & 0.811485 & 4 & 17.04119 & FALSE \\ Academia vs. Project Managers & 0.405088 & 0.982058 & 4 & 20.62322 & FALSE \\ Academia vs. Architect & 1.409879 & 0.842476 & 4 & 17.692 & FALSE \\ Academia vs. Business & 4.015701 & 0.403885 & 4 & 8.481588 & FALSE \\ Academia vs. Others & 2.885466 & 0.577172 & 4 & 12.1206 & FALSE \\ Project Managers vs. Architect & 1.428571 & 0.839214 & 4 & 17.6235 & FALSE \\ Project Managers vs. Business & 1.909778 & 0.752349 & 4 & 15.79932 & FALSE \\ Project Managers vs. Others & 2.81583 & 0.589103 & 4 & 12.37117 & FALSE \\ Architect vs. Business & 3.139717 & 0.534722 & 4 & 11.22917 & FALSE \\ Architect vs. Others & 1.224377 & 0.874069 & 4 & 18.35545 & FALSE \\ Business vs. Others & 2.033081 & 0.729674 & 4 & 15.32316 & FALSE \\ \hline \hline \end{tabular}
\end{table} 
Table 2: Statistical analysis of data to determine any significant variations using pairwise chi-squared test. Figure 8: (**a**) Inadequate collaboration between stakeholders in the value chain. (**b**) Breakdown according to professional background. To scale up circular solutions, it is essential to establish a circular construction ecosystem. Collaboration is needed between the public and private sectors, as well as within the private sector, to enable stakeholders to partner and build a network that promotes the implementation of closed-loop systems. The transfer of knowledge, along with making skills and resources accessible to partnering companies, fosters innovative approaches and resource-efficient practices. Within the individual responses of job roles, project managers ranked inadequate collaboration as a crucial hurdle, considering their responsibility for ensuring stakeholder management. Respondents were asked to rate if an important market and economic barrier to the advancement of a circular economy is that public procurement currently supports linear business models. Figure 9a,b outline the results, with a total of 67% of respondents agreeing that this was essential and very important. Public authorities own and manage large amounts of building stock. Yet, the adoption of the EU Green Public Procurement (GPP) criteria--an important driver of sustainability and decarbonisation in building and infrastructure construction--remains voluntary. Recently, a handbook was designed for the public sector by over 40 industry experts in collaboration with renowned law firms in Germany, ensuring that the guidelines and templates for circular public procurement in construction are legally compliant. The handbook showcases successful pilot projects and includes strategies for reusing materials and optimising processes with standards for pre-demolition audits. It focuses on reducing emissions, managing costs, and highlighting the public sector's role in leading the transition to circular construction [19]. Since 2022, the Scottish Government has required annual reporting of the prioritisation of the circular economy in all public procurements under policy note SPPN 3/2022 [20].