The objective of this research is to study the cost of Net Zero Energy (NZE) communities of different urban scales and densities, while taking into consideration the local climate and the type of buildings in the community. A comprehensive model was developed for this purpose, with which the cost-optimal configuration of renewable energy-related technologies for an NZE community can be identified. To validate the model, data from two case studies that differed in their climate and building types were used. The results of this study contribute to a better understanding of the implications of NZE requirements for urban planning. An increase in the scale of a community was found to reduce energy costs, up to a certain point. Urban density, on the other hand, was found to have a more complex impact on costs, which depends on the local climate of the community and the subsequent energy demand. This underlines the importance of addressing the technological design of energy systems at the initial stage of the urban planning of energy-efficient communities, before the urban density, the unbuilt areas and the building types are set.

Because of the fragmented nature of project information, decisions on changes in construction projects are usually based on project design instead of project requirements. This research proposes a new approach for coping with changes in construction projects: A change control tool (CCT) that will identify implications of a change as soon as it is proposed. The tool will ensure that the stakeholders involved in the decision process in which change proposals are evaluated will know in advance if a change could cause the project to stray from its original goals, as expressed in the requirements. The proposed CCT uses the building program as a link between client requirements and the building design and traces the different relationships that exist between the requirements in the project. The relationships are traced using requirement traceability capabilities on the level of a specific space in the project and on the level of the entire project. A preliminary CCT model was developed and pilot studies implementing the model have been conducted. The pilot studies have given positive results, indicating that the CCT could identify the scope of the proposed changes’ implications.