Membrane Sunspace for Old Buildings Refurbishment: Environmental Impact, Economic and Building Technology's Comparison to Conventional Solutions

Abstract

This study presents a state of the art and design proposal for membrane sunspaces, as alternative to conventional ones, in glass, commonly used in the functional refurbishment of old buildings. Sunspaces are passive solar systems that can be easily integrated in existing buildings. Enclosing balconies with glazing has an impact on existing building functional performance (useful area, thermal performance and acoustic improvement) and it may even postpone the renovation need of the intervened building. However, inevitably, many of old buildings are located in areas with access restrictions and other physical constraints on the movement of materials, components and equipment - that limits its construction and maintenance processes and thus demand for alternative solutions. Glass is being applied in all types of sunspaces, so architects and engineers take for granted that it has to be inevitably used. However, a major weakness of glass is its weight and cost, specially associated with installation complexity, framing systems and accessories needed. The fact that membrane requires less substructure, changes the architectural approach - giving more freedom to design options. Membrane construction technology and installation process could be a practical alternative to traditional construction methods for closing balconies in old buildings. For this research, a full-scale Membrane Alternative Sunspace prototype was implemented into an old building (taken as case study) to evaluate the real construction process aspects and compare it with the common glazed solutions. Results were examined from an environmental, economic and building technology's point of view - regarding production, construction and maintenance phases.