• The Duurzaam GWW Approach comprises a phased plan and a tool knows as Ambitieweb

  • A practical method for making sustainability in civil engineering projects concrete

  • We can offer advice to tendering parties and provide support throughout the process

Duurzaam GWW Approach

To make sustainability an integral part of the procurement and tendering process in the Netherlands, governments, knowledge institutes and businesses joined forces and established an expertise network for sustainable civil engineering – Duurzaam GWW.

The participants in Duurzaam GWW are Directorate-General of Public Works and Water Management (Rijkswaterstaat), ProRail, the Real Estate Department of the Ministry of Defence, the Agency for Sustainable Rural Development (DLG) of the Ministry of Economic Affairs, Agriculture and Innovation, the Sustainable Procurement Programme Directorate of the Ministry of Infrastructure and the Environment, the Union of Water Boards, the Association of Provinces (IPO), the Association of Netherlands Municipalities (VNG), the Dutch Construction and Infrastructure Federation (Bouwend Nederland), the Dutch Association of Consulting Engineers (NLIngenieurs), CROW, the Dutch Federation of Contracting SMEs (MKB-Infra) and NL Agency.

Duurzaam GWW Approach

The Duurzaam GWW Approach comprises a phased plan and a tool knows as Ambitieweb, a visual representation of the sustainability themes and the associated levels of ambition. The phased plan is a framework based on the stages of the procurement process, which can be applied to the individual process stages. Based on the phased plan, Ambitieweb is used to establish the sustainability ambitions for the project and the ambition is also made concrete. Another element in the Approach is the uniform application of tools including the CO2 Performance Ladder, DuboCalc, a software tool that calculates the environmental impact of the materials and energy used in infrastructure projects, and Omgevingswijzer, a questionnaire-based tool for the systematic assessment of the sustainability performance of structures and projects in a specific area.

The Approach makes the tendering process more tangible in terms of sustainability and is a practical method for making sustainability in civil engineering projects concrete.  At its core, the Approach serves to derive functional requirements from the ambitions and project needs. A key element therefore is to specify, record and implement ambitions, and to pass them on to the next project stage.

Phased plan

The phased plan specifies the required approach for each project stage aimed at making projects more sustainable. The specific phases used are universally applicable, which means the plan can be used in civil engineering regardless of the type of project or contract. This subdivision is unrelated to other phase subdivisions commonly used in civil engineering. In this way, the Approach can be used for both integrated and traditional contract types.

Witteveen+Bos actively contributes to the implementation of the Duurzaam GWW Approach by sharing experiences with other engineering agencies and clients, and by actively promoting and presenting the Approach. Witteveen+Bos can offer advice to tendering parties interested in using the Duurzaam GWW Approach on the best way of going about it, and provide support throughout the process.


Ambitieweb is a support model aimed at translating sustainability ambitions into practicable solutions for a project, and at specifying and managing those ambitions in the subsequent stage. Ambitieweb is a visual representation of sustainability topics and associated levels of ambition. In its completed form, Ambitieweb provides a starting point for drafting sustainability requirements. It comprises seven topics and three levels.

The topics are:

  • energy & climate (planet)
  • materials & resources (planet)
  • water & soil (planet)
  • nature & space (planet)
  • living environment (safety, health and nuisance, planet & people)
  • costs & value (profit)
  • accessibility (sustainable mobility, profit & people)

Each topic comprises three levels, i.e. insight, reduction and adding value.