Upcycling shipping containers as building components: an environmental impact assessment

Abstract

The introduction of shipping containers in the trading system has increased world economic growth exponentially. The main drawback of this linear economy consists in the accumulation of empty containers in import-based countries. Designers throughout the world are working with intermodal containers for environmental purposes, often employing them as building components. This research aims to evaluate the environmental impact of a container dwelling in comparison with similar steel and X-Lam structures. In order to estimate the effective sustainability of container structures, a comparative LCA has been undertaken. A cut-off approach was adopted focusing on Global Warming Potential (GWP), Ozone Depletion Potential (ODP), Acidification Potential (AP) and Eutrophication Potential (EP). To ensure reliable comparisons, a functional unit with combined spatial and thermal requirements has been defined. The proposed unit includes a total floor surface of 206.6 m2 and transmittance requirements in accordance with IECC standards. Three scenarios have been identified to address cold, temperate and hot climates within import-oriented places: Vancouver, Durban and Chennai. For hot climates the functional unit has been implemented with a minimum Periodic Thermal Transmittance. It can be generally stated that the use of shipping containers as building components leads to overall environmental benefits compared to steel and X-Lam structures within the boundaries of this analysis. The main advantages of container structures are related to easy reclaim of structural materials, creative reuse and shorter construction schedules. While the use of containers as building components demonstrated the best environmental advantages for cold climates, those benefits can be overturned by improper choices of thermal masses for hot and temperate climates. Empty containers are accumulated worldwide as a result of the linear nature of the trading system. With an upcycling process, the “stored” steel contained within abandoned freight containers is introduced into the circular economy of the building sector. Therefore, shipping containers can be regarded as waste objects that can be used as building components thus avoiding the use of steel from other processes or the extraction of virgin materials during the product stage. This upcycling process provides for each 200-m2 new house a general global warming potential reduction ranging from 20 to 25 tons of CO2 equivalent compared to steel frames and 10 to 26 tons reduction compared to x-lam structures in cold and hot climates, while resulting in an increment of + 3 tons in a temperate scenario.