Blast hardened buildings typically employ higher quantities of standard building materials than their conventionally designed counterparts to meet protective design requirements. Regarding the recent push for net-zero structures, it is important to explore the use of low-carbon materials in building design and other measures to mitigate embodied carbon in structures while maintaining a hardened blast envelope. A case study of a local, reinforced concrete building project with no existing protective design or sustainability requirements was redesigned to determine if it is possible to offset the additional embodied carbon from blast design for a more sustainable outcome. After blast hardening was applied to the building and the additional embodied carbon quantified, the standard concrete mix was converted to a low-carbon mix with the same strength, and it was found that the total embodied carbon in the project was reduced below that of the original, unhardened building.