This study addressed problems related to the protection, reconstruction, and revitalisation of modern heritage, particularly the regeneration of mass housing estates built after WWII and facing the contemporary perils of urban decay and deterioration. It presented interdisciplinary research investigating the possibility of extending and complementing the heritage assessment methodology and broadening the scope of the criteria by including mass housing landscape values. Starting with a close reading of the key theoretical positions embedded in the conceptualisation and construction of New Belgrade, we investigated a set of holistic and time-based criteria, followed by contemporary methodologies for landscape quality assessment. The investigation was based on an urban landscape approach to heritage assessment and focuses on the Central Zone of New Belgrade, declared a heritage site in 2021. The interaction of the theoretical underpinnings of modern architecture and urban planning with urban landscape discourse, coupled with historically and theoretically relevant knowledge and data, resulted in an investigation of landscape-based criteria for further mass housing assessment. Finally, we presented the findings of the landscape quality assessment of the transformations of the Central Zone. This perspective could be used to extend the possibilities of this approach in order to (1) tackle the “thickness” of temporality related to (urban) landscapes; (2) rethink and redefine the applied heritage assessment approach; (3) open the assessment procedure to a wider range of stakeholders, particularly nonexperts and the local community; and (4) re-actualise the position and role of experts in the sense of communicating knowledge in a completely new context.