## 4 Results and Discussion
### Challenges to Implementing Carbon Reduction Strategies in Construction Procurement
#### 4.2.2 Ambiguous Procurement Guidelines and Documents
Several participants said that even though some tender documents provided standard pricing information, including the LCC method, there was no reflection on the cost associated with carbon-related calculations and measurements. These results reflect those of [PERSON], [PERSON], [PERSON], and [PERSON] [13] and [PERSON], [PERSON], [PERSON], [PERSON], and [PERSON] [16] who have found that the tender document and its evaluation criteria must be better designed to support the successful implementation of carbon reduction procurement strategies. Suggestions for Improving the Implementation of Carbon Reduction Strategies in Construction Procurement  
The suggested support mechanisms for successfully implementing carbon reduction strategies in construction procurement identified by the interviewees generally focused on addressing the abovementioned challenges. However, it was believed that the key support mechanism that could be measured by construction professionals involved in the procurement process was improving the tender document. In particular, the tender document should clarify additional costs associated with applying carbon assessment methods and tools and following up on carbon performance estimations. This approach, which has not been widely recognised in the literature, helps set a budget for carbon-related initiatives and limits unexpected costs during project planning and implementation. In addition, the development of carbon reduction evaluation criteria in selecting stakeholders and proposed solutions to meet carbon reduction procurement requirements should be considered. This finding is consistent with experiences implementing procurement requirements for carbon reduction in other countries such as the US, the UK, Netherlands, Sweden, and Australia [9]. However, the participants in this study have determined significantly more detailed carbon reduction evaluation criteria in which the implementation of carbon reduction strategies in construction procurement could be better improved compared to those found in the literature. In terms of stakeholder selection, participants suggested the following carbon reduction evaluation criteria that should be considered when selecting consultants, contractors, subcontractors, and suppliers:  
* Experience in managing carbon-related issues in the procurement process;
* Ability to draw up specifications of carbon reduction strategies;
* Ability to work with clients and other stakeholders in terms of carbon-related functional characteristics;
* Experience in carbon reduction design and construction and whole-of-life carbon calculating and reporting;
* Ability to develop innovative design and construction strategies;
* Relevant qualifications and experiences in construction projects that focus on reducing carbon emissions;
* Reflections of carbon reduction measurements and management in the proposal and contract agreement. Regarding the evaluation criteria for assessing proposed solutions to meet carbon reduction procurement requirements, participants recommended that these criteria reflect the procurement outcome regarding carbon reduction, which should be specified in the request for the proposal and procurement plan. Including a comprehensive list of evaluation criteria in the tender document helps create a clear and consistent pathway for selecting ideal solutions.