In improving the sustainability of our built environment, we face challenges regarding energy, climate, and equality. In facing these challenges, European countries and institutions emphasise the need to protect and advance the cultural values of the built environment. However, the largest part of the stock that needs sustainable renovation is not listed, nor is its heritage significance assessed, detailing what is valuable (attributes) and why (values). Herein lies the risk that present significant attributes are not identified and maintained in future renovations, causing the loss of a variety of resources and their heritage significance. Moreover, the risk to destroy existing values and attributes can also reduce citizen’s support for future developments. This problem is faced by the housing stock built in Dutch cities between 1965 and 1985, which is more than 30% of the housing stock in the Netherlands. Although in recent years there is a growing attention for Dutch architecture built after 1965, there is a need for more knowledge about its heritage significance. In assessing everyday residential neighbourhoods, the need to involve citizens alongside experts is recommended. The societal relevance of this PhD research is underlined both at national and international levels, with respectively the Dutch ‘Post 65’ program, the upcoming Dutch Environmental Law (Omgevingswet), the European Faro Convention and its Dutch ratification, the Renovation Wave and European Green Deal, and the national and global housing crisis. The objectives of this PhD research are two-fold. First, it aims to reveal new knowledge about the attributes of 1965-1985 residential neighbourhoods. Second, it aims to contribute to the development and testing of methodologies that assess the heritage significance of residential neighbourhoods. The main research question is: What attributes of residential neighbourhoods, built in The Netherlands between 1965-1985, can be identified as significant by the involved stakeholders? This question is further deconstructed in three main components: how (methods), what (attributes) and who (stakeholders). The research adopts a broad conception of heritage, assuming that all buildings and neighbourhoods have heritage significance, including attributes that are valuable, to someone, in some form. These attributes can be the tangible embodiment of a value, but they can also be an intangible attribute, such as an event, use or meaning. The first part of the thesis explains the development of the research framework. An ‘integral view’ research approach allowed multiple value categories and stakeholder perspectives to be included. Exploration of a range of 1965-1985 residential neighbourhoods led to identification of main types, low-rise and mid-rise, that hold representative urban and architectural attributes and could serve as examples for the empirical research. The Heritage Cube developed by Peter Howard was adopted, adapted, and tested as a conceptual model for the operational framework. It integrates attributes, stakeholders, and scales, fitting the purpose of identifying attributes by different stakeholders and finding the potentially differentiated opinions of individuals and groups. The second part of the thesis explains the empirical qualitative research. The operational framework was used to examine three case studies, mixing methods, stakeholders and data collection. Methods included interviews, inductive and deductive coding methods for content analysis, followed by theory-building on stakeholder differences and attribute classification. Results show that by an ‘integral view’ research approach attributes can be identified in both tangible and intangible categories, and, on successive scale levels. The stakeholders involved in the identification have an influence on the attributes, as different stakeholder groups and different individuals show similarities but also focus on different attribute categories and scale levels. Attributes that were intended in the original planning and design of the neighbourhoods are currently assessed as significant but also later added or changed attributes. The research results suggest that attributes specific for 1965-1985 neighbourhoods are perceived as valuable, but also more generic attributes. The identification of this wide range of attributes, according to the ‘integral view’ and a broad definition of heritage, results from open-ended questioning by multiple participatory methods. A process of inductive analysis, classifying and relating attributes resulted in a network of attributes and sub-attributes that illustrates a shared narrative of a neighbourhood. The study provides insights and recommendations for practitioners in heritage participation regarding e.g. the participatory methods that can contribute to the democratic renewal as proposed by the European Faro Convention and the ‘integral view as a way of thinking for heritage professionals and agencies to assess residential neighbourhoods. The attributes and attribute categories identified in the empirical research can provide a basis for further exploration in the Post 65 inventories expected in Dutch municipalities and at the national level in the coming years. For academics, this research provides insights in the heritage assessment of significance by various stakeholders and individuals and the related influence on types and categories of attributes. This research has expanded the boundaries of what can constitute heritage by assessing the heritage significance of attributes in not-listed everyday neighbourhoods. Deep knowledge about attributes of the existing built environment informs efficient use of the existing ones and can help to refuse or rethink the use of new materials and thereby helping the circular economy. Further developing, testing and applying this broader heritage definition and related research methods can contribute to a more informed and sustainable renovation and development of the entire built environment, informed by its heritage significance, regardless of the heritage status.