From Building Reuse to Curtain Wall Refurbishment: A Study of Mid-20th Century Architecture – The Case of the Assolombarda Building.

This thesis explores the principles and practices of sustainable architecture, emphasizing the reuse, repurposing, and refurbishment of building facades. These strategies are crucial for reducing environmental impact while preserving the cultural and historical significance of structures. The research focuses on the unique challenges involved in refurbishing non-iconic architectural heritage buildings that possess distinct characteristics, with a particular focus on building envelope improvements, especially for mid-20th century buildings featuring curtain wall systems. The first chapter provides a broad exploration of the concept of building reuse, tracing its historical development and evolution across various architectural movements. The research examines different architectural discourses surrounding reuse, identifying critical points where restoration, preservation, refurbishment, and repurposing intersect. By balancing these approaches, the chapter highlights the importance of respecting the original structure’s integrity while adapting it for contemporary use. Through analysing selected case studies, the chapter outlines the advantages, limitations, and challenges of reusing existing buildings. Special attention is given to innovative approaches currently employed in the field, offering insights into how architects adapt to modern sustainability demands while maintaining historical integrity. The second chapter examines a selection of mid-20th-century buildings with similar curtain wall issues, analyzing their refurbishment projects to extract valuable insights and best practices. Case studies are organized into three categories—restoration, rehabilitation, and replacement—to assess varied approaches to curtain wall intervention. Each example provides a brief historical overview, an assessment of the building’s condition before intervention, and key considerations for each refurbishment approach. This analysis aims to inform effective strategies for future façade refurbishments of buildings with comparable characteristics. The third chapter focuses on refurbishing glass facades, with particular attention on mid-20th century metal-framed glazing systems, which became prevalent in this era but are not considered iconic in the same way as certain landmark buildings. This chapter explores strategies for upgrading these facades to comply with evolving building codes and regulations. By investigating the historical context of glass façade systems, the research analyzes successful refurbishment methods and identifies common technical and regulatory challenges. A real case study is then presented: the refurbishment of the curtain wall system of the Assolombarda Building (Gio Ponti, Antonio Fornaroli, Alberto Rosselli, 1958-64, Milan). The study proposes specific design interventions aimed at improving the building's curtain wall system to enhance thermal performance and increase occupant comfort, while also aligning with modern sustainability objectives. The redesign seeks to balance the need for modernization with the preservation of the building’s architectural significance. By applying these principles to a mid-20th-century structure, this chapter offers practical solutions for adapting glass facades to meet contemporary needs, while maintaining their historic character.