Transport Optimisation and Climate Impact of Mass Handling: Case Study of the Solhöjden Project

Abstract

Within the construction sector, the transport and handling of excavated materials are major contributors to both project costs and climate impact. In the European Union, excavated rock and soil accounted for approximately 20% of total waste generation in 2020, highlighting a significant potential for improved resource management. Transportation over long distances and competition between receiving facilities is a key driver of both costs and CO2e emissions. Reducing transport distances through alternative routes to receiving facilities, increasing reuse of excavated materials, and using electric lorries for transportation could significantly reduce climate impact. The aim of this study is to evaluate how design changes in the Solhöjden residential project in Kungälv, developed by JM, affected excavated mass quantities, transport demand, climate impact, and cost savings per apartment resulting from reduced excavation volumes. To achieve this aim, three different project design versions were compared. Project version 1 (PV1) represents the original design prior to redesign, PV2 includes a raised basement floor level, and PV3 involves a reduced basement. The analysis was based on Life Cycle Assessment (LCA) in OpenLCA, combined with GIS-based modelling of transport routes to receiving facilities. The input data was primarily provided by JM and included delivery notes specifying transported weights, material types, vehicle types, and receiving locations. The study used a case study approach supported by interviews to obtain project specific information that could not be derived solely from the literature. The results show that design changes, including basement layout modifications, reduced excavation volumes and enabled construction of the project. Between PV1 and PV3, the total quantity of excavated masses decreased by approximately 28%, demonstrating substantial mass savings due to design changes. Costs related to excavation, tipping, and transportation were reduced by approximately 13,000 SEK between PV1 and PV3-RO (route optimised). Furthermore, replacing conventional lorries with electric lorries resulted in an approximate 17% reduction in total emissions, with near-zero direct emissions during operation. The study also identified that permitting processes, differences in municipal regulations, and a limited availability of receiving facilities often contribute to longer transport distances and create additional challenges in the management of excavated materials.