The future of modernist housing estates: The "replace vs Refurbish" dilemma in the context of future urban densification

The aim of this paper is to present a part of the research developed inside the author's dissertation topic which deals with the future of large modernist housing estates. The central question of the dissertation investigates which of the currently dominating tendencies - their replacement or refurbishment - result in lower energy consumption and provides more sustainable use of natural resources within the context of future urban densification. The presented workflow combines actions contained in the first step of the research methodology built around the abovementioned dilemma. It explores the solar energy harvesting potential of various urban forms and densification scenarios, proposed inside the main "refurbishment" and "replacement" approaches, including both retain and demolition options of the existing building stock located in the Nordweststadt housing estate in Frankfurt, Germany. All scenarios are tested against maximal density rate which secures enough operational energy from on-site renewable energy sources for the achievement of the zero energy building (ZEB) standard. The expected outcome of this paper gives an insight which of the proposed densification scenarios from both approaches generate the highest density rate in respect to the given boundary conditions, and compares the energy balance between the best performing scenarios in both approaches at the same density level.