Multifunctionality as a Strategy to Decrease Resource Use in Building Envelopes
The growing use of renewable and non-renewable resources by human society is increasingly seen as one of the root causes of the occurring imbalance in the global ecosystem. The effects are inter alia made responsible for a severe disruption in climate, loss of biodiversity, water shortage and a looming energy crisis that combined threaten human prosperity and livelihood. As a response to the occurring problems, global commitment to sustainable development is envisaged. In this context the building industry has a great responsibility as it's leverage as one of the biggest stakeholders in global material flows is significant. It will increasingly have to provide credible solutions and strategies to not only qualitatively change the composition of the triggered material flows, but to reduce the absolute consumption of raw and refined materials and generation of material flows to a sustainable level. The research presented in this thesis therefore analyses different strategies that can lead to the reduction of resource use in architecture, focussing on multifunctionality. A discussion of constructional principles of the building envelope analyses how multifunctionality can be achieved. A material intensity analysis using the material input per service unit concept (MIPS) quantifies the potential of multifunctionality to reduce resource use by comparing the material flows of a conventional and a multifunctional envelope. The case study shows that multifunctionality has the potential to reduce the resource use of building envelopes, if synergistic effects are created and if life-cycle wide resource flows are taken into account at the design stage. Both the theoretical first part and the case study in the second part of the thesis underline that the success of multifunctionality in contributing to resource flow reductions is highly dependent on the designer's awareness of the importance of material flows in the built environment and willingness to approach the topic with flexible design solutions. Furthermore it is underlined that only a combination of different strategies which address the topic at different leverage points will lead to the necessary absolute reduction in material flows.