## 3 Obstacles to the Implementation of LCA in the Procurement Process of Buildings
### Political Obstacles  
In the context of the obstacles under policy aspects, municipal authorities did not use the right to set sustainability requirements as award criteria. Further obstacles mentioned in the literature were the lack of a comprehensive strategy for public procurement and the lack of governance of regulation, regardless of its nature, which could be either performance-based or prescriptive [67]. Moreover, it was mentioned that more than just the indicator of global warming potential (GWP) should be considered as environmental criteria [93]. Lastly, missing supporting initiatives for the implementation of LCA in the  
\begin{table}
\begin{tabular}{l c} \hline \hline
**Legal Obstacles** & **Reference** \\ \hline _Content analysis of the documents obtained from calls for tenders_ & \\ _Comparison of environmental criteria in tenders_ & \\ \(\rightarrow\) Missing compulsory environmental requirements for & [61] \\ LCA implementation & \\ \hline _Semi-structured interviews on the subjects of current practices and obstacles_ & \\ _to environmental requirements in construction_ & \\ _Survey on the subject of the existence of municipal policies dealing_ & [62] \\ _with environmental issues_ & \\ \(\rightarrow\) Law is unclear regarding environmental requirements & \\ \hline _Assessment of the determinants and drawbacks of green procurement adoption_ & \\ \(\rightarrow\) Absence of extensive and well-defined rules for incorporating & \\ environmental criteria into procurement procedures and the awarding & \\ of contracts for goods and services & \\ \hline _Assessing the environmental impact of road works to promote green_ & \\ _procurement using multi-criteria analysis_ & [90] \\ \(\rightarrow\) Missing compulsory environmental requirements & \\ \hline _LCA is applied for two products to support procurement decision_ & [91] \\ \(\rightarrow\) Lack of consistent format in terms of legal requirements & \\ \hline _Review of EPDs_ & \\ _Comparison of EPDs and NAPs_ & [101] \\ \(\rightarrow\) No regulations for public tenders & \\ \hline \hline \end{tabular}
\end{table}
Table 3: Legal obstacles to LCA implementation in the procurement process of buildings.  
provement process were highlighted as a problem [94]. Table 4 provides an overview of the identified political obstacles.  
Among the political obstacles to implementation, the lack of comprehensive strategies for public procurement was mentioned. Clear strategies for implementing LCA in the tendering and awarding process of buildings do not exist to a sufficient extent. However, sustainability strategies, in general, are increasingly being pushed forward. In this regard, the 17 Sustainable Development Goals (SDGs) within the framework of the 2030 Agenda must be mentioned [4]. Within these goals, SDG 11 \"Sustainable Cities and Communities\" should be highlighted, which, among other issues, promotes more environmentally friendly construction. As part of the UniNetZ research project, options for action were developed for the Austrian federal government to achieve the SDGs, which, among other matters, also propose and explain the implementation of LCA in the procurement process of buildings [103]. Another policy instrument that has already been implemented in the context of CO2 emissions reduction is the implementation of CO2 taxes.  
Another obstacle to implementation mentioned was the lack of supporting initiatives. An organization, e.g., a publicly financed consulting office, could be established here, at least for public buildings, which would provide support in adapting the tender documents, as well as sustainability experts who would carry out the transparent evaluation of the bids. A public consulting office can also overcome the implementation obstacle of municipalities not using the right to set sustainability requirements as award criteria.