*4.3. Evaluation of Barriers to Effective and Sustainable C&DWM*

Based on the results obtained from the experts, the estimated RI values range from 0.45 to 0.70, as shown in Figure 4. These values were divided into three levels: strong barriers (0.60–0.70), moderate barriers (0.50–0.60), and weak barriers (<0.50).

**Figure 4.** Variation of RI index for UK, Ghana, KSA, and Egypt.

#### 4.3.1. Critical Barriers in the UK

According to the questionnaire in the UK, B4, B3, B7, B8, and B2 constitute the five strongest barriers to effective and sustainable C&DWM. Additionally, B1, B5, and B6 were regarded as moderate barriers to effective and sustainable C&DW. Notwithstanding these, the UK Government has been using a combination of regulations, economic instruments, and voluntary agreements to meet targets of ethical, social, and environmental performance in driving the waste management agenda [71,72]. Also, the UK implements legislative and fiscal measures which lead not only to construction waste reduction, but are directly related to the rising landfill tax, increasing cost for waste disposal, and compliance requirements with site waste management regulations from 2008 [73,74].
