A few years ago, a bridge rehabilitation project I worked on came down to two options. The first was a conventional replacement: remove the existing structure and build new. The second option would have retained most of the superstructure, reduced new material use, and lowered embodied carbon while meeting performance requirements. Both were technically viable. The lifecycle case for rehabilitation was more than credible. But as the project moved through feasibility review, procurement scoring, and value engineering, the lower-carbon rehab option failed to advance—not because the idea of addressing embodied carbon was dismissed, but because the decision process the project moved through was not structured to weigh it. Sadly, nothing about this outcome is unusual. Situations like this are common in infrastructure work. These projects are rarely framed as carbon decisions, even when they are. They’re also largely absent from the broader embodied carbon conversation, which has understandably focused on buildings. 

What the Building Sector Built

Over the past decade, the design community has assembled a working ecosystem for addressing embodied carbon in buildings. Life cycle assessment has moved into practice. Environmental Product Declarations (EPDs) have made product-level comparisons possible. Buy Clean policies—first implemented in California and now adopted in various forms by Colorado, Oregon, and Washington—have started linking public procurement to material emissions. Tools such as EC3 and tallyLCA have made carbon visible during design, when decisions can still change outcomes. None of this is close to complete. But these steps have created a scaffolding of standards, data, tools, and procurement pathways that allows embodied carbon to be evaluated as part of normal design and specification. That shift from aspiration to integration is what has made progress possible.

What Infrastructure Looks Like by Comparison

Equivalent practice in infrastructure is slowly emerging but remains uneven. Bridges, transit systems, water networks, and underground assets operate across fragmented ownership structures, varied design codes, and inconsistent procurement frameworks. Yet efforts are underway to change this. The ASCE Infrastructure 2050 initiative is focused specifically on infrastructure, while the SE 2050 Commitment has advanced embodied carbon practice in structural systems more broadly. The Envision framework, developed by the Institute for Sustainable Infrastructure, provides a sustainability rating system for civil infrastructure. At the federal level, programs administered by the Federal Highway Administration have directed more than a billion dollars toward studying, tracking, and procuring lower-carbon materials in transportation projects.

But the ecosystem is still developing. Baselines are not consistently defined across asset types. Product-level data is uneven. Tools that integrate into infrastructure workflows are less mature than their building sector counterparts. Policy direction has also evolved, with state-level Buy Clean programs and multistate collaborations continuing to advance procurement alignment, alongside federal funding that is already in implementation. Infrastructure has not missed the conversation, but the institutional landscape it moves through is more fragmented.

Where the Gap Shows Up Inside Projects

On the ground, the gap appears in all of the familiar places:

• In feasibility studies, where alternatives are compared against cost baselines drawn from historical project data, and where carbon and lifecycle considerations, if included at all, are often presented separately and rarely shape the final recommendation.
• In value engineering, where budget pressure leads to the removal of elements perceived as additive. A supplementary cementitious material mix, a salvaged steel component, or a design refinement that reduces material volume can be set aside when the immediate pressure is to reduce cost, even when those strategies improve long-term performance.
• In procurement, a lower carbon material or method can pass technical review but carries little or no weight in the criteria that determine which bid is selected. Many state departments of transportation continue to evaluate bids primarily on price and technical compliance, with carbon either absent from the scoring rubric or treated as supplemental information. This is often where lower-carbon options that were viable earlier in design fall out of consideration.
• And in risk management, teams weigh whether to specify less familiar alternatives and often conclude that conventional solutions are the more defensible choice within existing incentives. A project manager who delivers a conventional design on schedule is rewarded; one who delivers a lower-carbon design on schedule is acknowledged. That asymmetry shapes decisions.

None of these dynamics is unique to infrastructure. But in buildings, a more-developed ecosystem, supported by rating systems such as LEED and tools that integrate product-level data into design workflows, increasingly allows lower-carbon options to compete. In infrastructure, that support system is still forming.

What It Would Take To Close the Gap

The building sector did not advance embodied carbon reduction by adding new conversations. It did so by embedding carbon into the decisions already being made. EPDs aligned with specification processes. Design tools integrated into workflows already in use. Buy Clean policies attached carbon performance to procurement systems that already governed spending.

Infrastructure decisions operate through a similar logic, but with a different emphasis. Cost, schedule certainty, lifecycle maintenance, and delivery risk are evaluated together, often under tight constraints. Life cycle cost analysis and risk-based asset management are already part of this framework, closely aligned with what is often referred to as techno-economic analysis in other sectors. What remains inconsistent is the pairing. Embodied carbon analysis is often conducted separately from the cost and risk evaluations that determine outcomes. Bringing these together at the stage when alternatives are defined, budgets are set, and procurement strategies are structured is where the opportunity lies.

Examples of Integration

Some systems have started to do this:

• The U.K.’s National Highways net-zero program has developed material-specific decarbonization pathways for concrete, steel, and asphalt, and maintains a register of lower-carbon opportunities that project teams can draw from.
• The Netherlands’ Rijkswaterstaat approach uses its DuboCalc tool to evaluate lifecycle environmental impacts and convert them into an environmental cost indicator that is incorporated into bid evaluation alongside price. Designs with lower environmental impact can improve their competitive position in procurement. This approach has been used in infrastructure tenders for over a decade and is now widely applied on major projects.

These are not pilot efforts—they are institutional approaches that demonstrate carbon can be integrated into infrastructure decisions without displacing cost discipline.

There are early examples in the U.S. as well. State transportation agencies, including Caltrans in California and CDOT in Colorado, have started incorporating EPD requirements into selected procurements, and state-level Buy Clean programs continue to expand. Federal funding already allocated to low-carbon materials programs is now being implemented across multiple states.

An Invitation

Infrastructure carries a significant share of the built environment’s emissions and will absorb much of the climate adaptation effort in the decades ahead. It is also a space where architects, engineers, owners, and public agencies are working toward similar goals from different positions.

Much of what has been developed for buildings is adaptable, not as a direct transfer, but as a set of lessons about how change takes hold. Progress came when carbon became part of decisions already being made, not an additional layer alongside them. Closing the gap in infrastructure will follow a similar path. It will depend on pairing carbon analysis with the cost and risk frameworks that already govern projects, and on building the institutional support to make that pairing consistent across owners and asset types.

The bridge rehabilitation project I opened with did not go the way I had hoped. But it reflected the system it moved through. Changing outcomes will depend on changing that system incrementally, across many projects, until different decisions become the default option.

Featured image via Creative Commons.