It is estimated that around 40-50% of natural resources are transformed into construction material, and that as much as 30% of all building materials delivered to a construction site end up in waste. To minimize this, it is important to ensure that the procurement process allows for careful and detailed planning of resource use during the project. In order to promote this, and encourage the use of sustainable materials, the following data should be captured during the project:
The estimated material use during a project should be recorded. This data will include the type, quantity, and quality of the materials. Although the sustainability impact of material use will depend on the type and quality of the materials, capturing the quantity is essential, as projects with lower material use usually have a lower environmental impact. However, it is also important to take into account what % of this material is, as described below, reused or more sustainable.
The quantity of materials available on-site that are reused during the project should be recorded. This is particularly relevant in refurbishment projects, where a pre-procurement evaluation of the quantity and type of available materials should be conducted. Generally, the more materials are reused, the lower the environmental impact of the project will be.
The quantity of more sustainable material use should be captured. Sustainable materials can include, for example, materials that comply with the standards of any existing accreditations (i.e. if they are Type 1 accredited ecolabelled materials). A higher use of these materials will usually lower the environmental impact of the project.
Vehicle and transport use
It is estimated that construction projects account for the largest share of both global final energy use (36%) and energy-related CO2 emissions (39%). Although not all of these emissions derive from vehicle use, it is also important to monitor and capture the following:
The total vehicle use can be captured during the project. This data will normally include the number of vehicles used during the project, and the hours of use for each vehicle. Less hours of vehicle use will normally result in a lower environmental impact. However, this will also depend, as explained below, on the vehicles’ emission standards.
The emission standards of the vehicles used during the project should be captured. The European Emission Standards can help as guidance. Despite being European, these standards have been used by UNEP to evaluate vehicle emissions in LAC and Africa, and West Africa has used these standards to develop their new vehicle emissions regulation.
- Petrol: CO: 2.3G/km; THC:0.20g/km; NOx: 0.15 g/km/
- Diesel: CO: 0.66g/km; HC + NOx: 0.56g/km; NOx: 0.50g/km; PM: 0.05g/km.
Transport use can be captured in kilometers, and can include, for example, the kilometers that workers have to do in order to get to the construction site. However, the transport use that can have the biggest environmental impact during a construction project is the one related to material delivery. This includes the number of material deliveries to the site, and the associated kilometers per mode of transport used.
Grouping shipments, sourcing local materials, and using more sustainable modes of transport will help to minimize the impact of transport use.
Construction projects, especially those in the construction, refurbishment, and deconstruction stages, involve the generation of great quantities of waste. To minimize and monitor waste generation, the following data can be captured:
The quantity of waste generated during a construction project should be captured. This can be collected in terms of volume (m3) or weight (kilograms or tonnes). Information regarding waste should also include the type of waste generated (especially regarding hazardous waste).
Lowering the amount of waste generated during a project will also lower the environmental impact of the project. However, in terms of sustainability, it is also important to capture data that shows what % of the generated waste is diverted from landfill.
Minimizing waste generation will help to lower the environmental impact of the construction project. However, diverting the generated waste from landfill will also help towards minimizing this impact. This data should also be captured, and it will include the volume (m3), or weight (kilograms and tonnes), of waste that is reused, or recycled.
In order to monitor the economic and social impact of a construction project, data can be collected regarding:
Data should be recorded regarding the companies that are involved in the supply chain, especially the number of SMEs, local, and women-led companies.
Data regarding the employees that will be involved during the project can be collected, including the employee data from the suppliers, and subcontractors. This data can include the number of employees contracted as part of the project, as well as the number of hours of work per employee.
- Civil Works Contract Model. IHOBE (ES)
- EU Green Public Procurement Criteria for Road Design, Construction and Maintenance. 2016. European Commission
- EU GPP Criteria for Office Building Design, Construction and Management. 2016. European Commission
IHOBE provides examples of how to introduce sustainability criteria regarding construction materials on a tender document, as well as how data should be required of the bidders.