A recently published research paper demonstrates how current building structures hardly achieve a 4% structural efficiency, in other words they use 25 times more material than the minimum theoretically required.
Existing methods to assess structural design have been using indirect magnitudes -self-weight, embodied carbon- hence the structural capacity inherent to the material got lost in the process.
Instead, the novel Structural Efficiency Classification System -or S.E.C.S for short- measures “Stress Volume” i.e. the capacity of the material to translate forces over distances; hence it works consistently across materials.
Also, any building is compared to a theoretical optimal model resolving the very same structural problem, and the ratio between the stress volume of the theoretical optimal and the real design becomes the Structural Efficiency or SE.
The method is public and its theoretical foundations described in the paper:
Mena Q (2020) Towards a Structural Efficiency Classification System
(Structures, Volume 26, August 2020, Pages 298-310)
In that paper you’ll find:
- how buildings designed following design guides do not achieve structural efficiencies over 5%
- it is possible to design floor systems up to 50% structural efficiency: e.g. in steel/concrete, their self-weight is under 40 kg/m2
( As a reference: latest design derived from the direct application of the S.E.C.S. principles is a residential square floor, 4.2m side simply supported at corners and using existing standard materials. Its self-weight is under 15 kg/m2 and its embodied carbon also less than 15 kgCO2e/m2 )