*2.4.1 Selecting sustainable material suppliers and manufacturers*

Purchase of materials is commonly done through bidding and choosing the least expensive bidder that meets the expected quality. Less attention is paid to how sustainably the supplier or manufacturer procures the material. Selecting the material supplier is a multi-criteria decision [26, 27]. Selection criteria of material supplier or manufacturer must modify and include the following criteria (**Figure 9**).



**Figure 9.**

*Selection criteria of material supplier or manufacturer.*

• Disclosure of material ingredients. The supplier must disclose the life-cycle information of the chemicals they have used in the product. This is more important for the infrastructure facilities that are in the proximity of children or other sensitive groups.
