Design Solution · Structural Systems
Design Solution · Dream about it
Reduce structural mass and slab thickness to lower embodied carbon and foundation loads.
Leaner structures carry less embodied carbon: lighter superstructure means smaller, less impactful foundations, and reducing in-situ slab thickness cuts concrete by roughly 11% per 50mm. Avoiding cantilevers and thick balcony slabs, and tuning grid spans, keeps material use efficient.
Reducing structural mass — through thinner slabs, more efficient grid spans, and eliminating unnecessary concrete in cantilevers and balcony edges — compounds through the building: less superstructure weight means smaller, lighter foundations, and every 50mm off a flat slab cuts concrete volume by approximately 11% per floor. As a whole-building embodied-carbon strategy, this is among the highest-leverage structural decisions, partly because it addresses the largest material mass category and partly because it is made at concept design stage when it is still free. This record sits at claimed status with no verified project evidence, but the engineering logic is well-grounded in established structural principles and there is no fundamental uncertainty about the relationship between mass and carbon. The practical value is that structural optimisation does not require novel materials or procurement relationships — it requires disciplined early collaboration between architect and structural engineer to resist the tendency toward conservative section sizes, and careful checking of assumed cantilever requirements and balcony configurations that often drive slab thickness beyond structural necessity. The honest trade-off is that thinner slabs typically reduce acoustic performance between floors and may increase deflection under variable loading, requiring more refined structural analysis and potential post-tensioning to achieve the same span; the carbon saving from a leaner structure must be weighed against the carbon cost of any post-tensioning system or additional reinforcement that compensates for reduced depth. Whole-building structural carbon modelling, iterated with the LCA team from RIBA Stage 1, is the correct workflow.
#structure #slab #embodied carbon #grid span