3D Printed Concrete Buildings Have Zero Provisions in U.S. Building Codes

As of the 2024 International Building Code (IBC), there are zero provisions for 3D printed concrete (3DCP) construction. The IBC and IRC — the basis for state building codes across the United States — do not recognize additively constructed concrete as a construction method. The only pathway for permitting is IBC Section 104.11 (alternative materials/methods), which requires expensive case-by-case evaluation by local officials who typically have no expertise in 3DCP. Three separate organizations — ICC, ACI, and ASTM — are developing standards in parallel with limited coordination, and NIST has flagged the risk of inconsistent guidance.

3DCP promises 30-50% reductions in construction time, significant labor cost savings, and the ability to create complex geometries impossible with traditional formwork. In a housing crisis where construction labor shortages are acute, this technology could meaningfully expand housing supply. But every 3DCP project in the U.S. requires jurisdiction-specific alternative materials approval. Structural performance is currently limited to one-story, Risk Category I/II structures in Seismic Design Categories A and B only — excluding most of California, the Pacific Northwest, and the Southeast. The next IBC update cycle is 2027, and state adoption typically lags 2-5 years beyond that.

ICC published the first draft of ICC 1150 in November 2024, but it remains in public comment and covers only 3D concrete walls. ASTM F42.07.07 is developing test methods for cementitious AM materials. ACI Committee 564 and ITG-12 are developing code requirements targeting incorporation into ACI 332 by 2026. NIST and U.S. Army ERDC co-hosted a 2025 workshop to coordinate these parallel efforts. However, the three standards tracks are structurally uncoordinated: ICC writes building codes, ACI writes concrete design standards, and ASTM writes test methods — and none reference each other's drafts. Existing ASTM C09 concrete test methods do not directly apply because 3DCP processes fundamentally alter how specimens are sampled, consolidated, and extracted. ICON (the leading U.S. 3DCP company) must obtain individual ICC-ES evaluation reports for each wall system variant, an expensive and slow process.

A validated, consensus-based set of mechanical property test methods specifically designed for 3DCP specimens (addressing anisotropy from layer-by-layer deposition), plus a prescriptive code pathway for at least simple residential structures. The test methods need to account for the fact that 3DCP creates directionally-dependent material properties — compressive strength parallel to layers differs from perpendicular — which traditional cylinder compression tests don't capture. An integration standard that bridges ICC, ACI, and ASTM work products would prevent years of rework.

A team could 3D print concrete specimens with a small-scale concrete printer, test them for compressive and flexural strength in multiple orientations (parallel and perpendicular to print layers), and compare results to traditional cast concrete. This would directly contribute data to the test method development ASTM F42.07.07 needs. A complementary approach would be surveying local building officials to assess their readiness to evaluate 3DCP permit applications — generating data on the adoption bottleneck. Relevant disciplines: civil/structural engineering, materials science, construction management, policy.