Material specifications affect construction schedules, structural performance, and procurement costs. Concrete composition influences curing requirements, while steel production routes affect emissions and exposure to energy prices. Product selection therefore forms part of technical design and commercial planning.

Lower carbon procurement requires clear performance criteria and comparable environmental data. Specifications establish the standards for strength, durability, availability, and emissions that suppliers must meet.

Carbon accounting boundaries

The World Steel Association reports an average carbon footprint of 2.18 tonnes of CO₂ equivalent per tonne of steel in 2024, covering scopes 1, 2, and 3. This global average reflects sector performance. Project assessments require data for the steel that the contractor purchases.

A mill using scrap and an electric arc furnace follows a different production route from a conventional blast furnace. Electricity supply, material inputs, and transport also affect emissions. Product comparisons require a declared carbon value, a consistent assessment boundary, and supporting evidence for the proposed supply.

Concrete comparisons require a reference mix, a defined strength grade, and a specified unit. These parameters establish the basis for any reported percentage reduction.

Clinker substitution through LC3

Limestone calcined clay cement, or LC3, reduces clinker content through a combination of calcined clay and limestone. The LC3 research programme describes a blend comprising 50% clinker, 30% calcined clay, and 15% limestone, with gypsum completing the formulation.

The programme reports potential CO₂ savings of up to 40% compared with ordinary Portland cement. The actual carbon footprint depends on the specific blend, energy sources, transport, and reference cement. Clay processing also requires energy.

Technical submissions must include a carbon assessment and evidence of performance for the intended application. Strength development, curing, and exposure conditions determine whether the proposed mix meets project requirements.

Local benchmarks for concrete procurement

On 26 February 2026, CapitaLand Development and Climate Group launch Concrete Data for Concrete Action. The initiative establishes a Singapore market benchmark using verified supplier data and comparisons across concrete strength grades.

The benchmark supports comparisons between a proposed mix and the local reference for its strength grade. Procurement teams can review the composition, assessment boundary, and supplier evidence behind the reported differences.

Certification requirements depend on the scheme version and applicable dates. The Building and Construction Authority announces Green Mark Version 7 on 2 September 2026. Teams preparing a submission must confirm the criteria and transition requirements that apply to their project.

Procurement and supply verification

A lower carbon material must meet the construction schedule and environmental targets. Production consistency, curing requirements, and delivery capacity determine its suitability for the site.

A comprehensive procurement brief defines strength and durability criteria, sets a carbon target against a specified baseline, and requires product-specific evidence. It also establishes supply capacity and procedures for changes to the approved formulation.

These requirements allow suppliers to compete against common technical and environmental criteria. The client can then assess carbon reduction claims alongside the material performance and supply conditions that the project requires.