Holistic evaluation of tensegrity vs. conventional structures through a new LCA-LCC methodology: Stage-by-stage environmental and economic assessment

Tensegrity structures (TS) can be applied in architecture, as long as essential conditions such as deformation limits are met. These structures aim, among other objectives, to achieve lower energy demand and a reduction in environmental impacts across all project phases, and usually offer advantages in mass optimisation, ease of assembly, cost reduction, and construction safety. However, no studies have hitherto focused on efficiency data in this domain. A real case was addressed in this study: a TS footbridge located at high altitude in Ordino (Andorra). It was built with S275J2 steel and assembled by helicopter, so transport logistics had a significant impact. Two structural design alternatives based on conventional systems were advanced, comparing their carbon footprint, environmental impacts and costs with the TS solution. To this end, a new holistic assessment methodology was developed, combining Life Cycle Assessment (LCA) and Life Cycle Costing (LCC) called LHA-LC (Life Holistic Assessment). The methodology introduces the concept of constructive efficiency, from both an environmental and economic perspective. Furthermore, the methodology involved the novel stage-by-stage application of the EN 15804 + A2:2020 modules within the LCC analysis, thereby enabling a more structured and granular comparative assessment of the environmental and financial impacts. The TS solution achieved, from cradle-to-cradle, a maximum reduction of 27.5% in the GWP-total carbon footprint, ranging between 22% and 61% in the rest of the 12 environmental impacts. It also resulted in a maximum reduction of 22.2% in financial cost. A complementary scenario excluding helicopter use was examined, yielding similar reductions. The findings highlight the usual benefits of TS design in minimising environmental impacts and reducing costs compared with conventional systems.