The development of a Multi-Criteria Assessment Model for NOx emission reducing solutions for contractors in the realization phase of utility construction.

Developments regarding sustainability and emission performance of buildings are highly associated with the nowadays construction industry. In most cases, (new) law and regulations determine the standard, however, companies often have the ambition to perform above the legal standard. This research anticipates to this by the development of a Multi-Criteria Assessment Model that can identify NOx reducing solutions in an early stage of a utility construction project based on the overall performance of criteria. The required model input is available in the initial phase, thus, at that moment, it could be determined which NOx reducing solutions are the best fit for a specific project in an early stage of a project. By means of the AERIUS calculation, it is determined whether a project meets the emission requirements defined in the “Programma Aanpak Stikstof” (PAS), which is in force since a judgment of the Council of State at the 29th of May 2019. The reducing solutions which are the result of the model developed in this thesis can be applied to ensure a project will meet these requirements.

The sudden judgment of the Council of State has resulted in an instant stop for several construction projects that were in development. Although a permit was already granted, these kinds of projects had to apply for a permit again. After this judgment, contractors should examine projects through the AERIUS Calculator to calculate the NOx deposition in Natura 2000 areas to determine whether the critical deposition values are exceeded or not.

In case of exceeding this threshold, NOx reducing solutions have to be introduced to ensure that the critical NOx deposition value is not exceeded. In the construction industry, there is a need to efficiently deal with these reducing solutions because these always will result in higher costs, additional labor, and other difficulties.

However, the cheapest solution is often chosen in practice, but this is not always the best possible solution. Therefore, a Multi-Criteria Assessment model with several criteria is proposed in this thesis. These criteria include different aspects such as NOx and CO2emissions, costs, electrification and others that influence the performance of reducing solutions.

Since each construction project is different, there is a need for a specific set of reducing solutions per project. The model developed in this thesis determines criteria weights based on project-specific characteristics of a project. In most situations, Multi-Criteria Assessment models are complex environments that are controlled and used by experienced decision-makers only. Therefore, the intention of this model is to ensure that every employee should be able to use the model without any specific knowledge. To achieve this, the model is set up in such a way that users only must fill in a pre-defined list of questions which eventually result in the output of the model.

The development of the model requires background information on different topics. In the literature research, attention is paid to the characteristics of NOx, impact on human health, and the environment. Furthermore, the emission sources are reviewed and the current situation regarding the NOx problematics in the Netherlands is discussed. Additional interest is given to the resurrection of the PAS policy; what has changed after 2019, and the consequences for the current construction industry. Complementary, an analysis of the AERIUS Calculation is performed to ensure all relevant elements are covered. Lastly, NOx reducing measures in construction, transportation, and industry are provided as far as identified by this research.

In this thesis, several similar models are evaluated and discussed to bring in usable theories of other researchers. In addition, interviews were conducted internally and externally to identify relevant project-specific information and reducing solutions. Based on the acquired information at that point, a flowchart is developed and the most crucial steps of the model are presented. This flowchart, combined with previously gained knowledge in this thesis led to the Proof of Concept of the Multi-Criteria Assessment Model.

To be able to test the model, a project that was executed after the judgment of the Council of State was selected. The project-specific information of this project is used as input for the proposed model, and afterward, it is tested whether the outcome of the model reflects the experiences of the project in practice. According to the first output, the model parameters were adjusted to increase the reliability of the model. It was found that the model can be used during the development phase of construction. However, at this experimental stage, the model is highly based on assumptions, and therefore, future research is required to adjust the reference framework to actual executed projects.