Every development team I've sat with runs its sustainability review in more or less the same order. The mechanical plant gets scrutinized. Someone models the envelope. The renewables get costed, and the group builds a defensible picture of how the building will perform once tenants move in. By the time the review wraps, operational carbon has a plan attached to it.
The parking structure oftentimes doesn’t make that agenda. It sits in the drawings as infrastructure, fully priced and fully engineered, and the carbon conversation skips right over it. That omission is getting harder to justify.
The embodied carbon of building structure, substructure, and enclosure already accounts for about 11 percent of global greenhouse gas emissions, and the garage holds some of the most carbon-dense material on the entire site. So what turns up when it runs through the same analysis every other system gets?Operational carbon and embodied carbon split on timing. Operational carbon tracks the energy a building burns across its working life, the figure that efficiency upgrades and a cleaner grid keep pulling down. Embodied carbon captures what construction locks in, the emissions bound up in producing and assembling the materials themselves. Operating emissions stay negotiable for decades. Embodied carbon gets spent the day the concrete cures, and no retrofit claws it back.
That timing is why the ratio keeps tilting. Every gain in operational efficiency makes embodied carbon a larger slice of the lifecycle total, which steadily pushes it up the priority list for anyone serious about a project's footprint.
Consider what a garage is. Concrete and steel, poured and erected in volume. Those materials, together with aluminum, drive roughly 23 percent of global emissions. A parking structure concentrates the highest-emitting inputs in the built environment and commits them all in a single push.
The budget runs on a parallel track. WGI's parking cost research pegged the 2024 national median at roughly $29,900 per structured space. Multiply that across a few hundred spaces and the garage becomes one of the largest capital items in the whole development. All that spending buys a lot of concrete and steel, and every yard of it carries embodied carbon that never makes the sustainability tally.
For years, parking sat in the code as a fixed requirement, a box you checked. Now statutes are rewriting it as a climate variable, with California's AB 2097 barring cities from setting parking minimums near transit. Its own legislative findings state that mandatory parking minimums raise housing costs and increase greenhouse gas emissions. Lawmakers wrote the budget effect and the carbon effect into the same clause, which signals how they now read the asset.
Researchers have been putting figures to that connection. Work from UCLA's Institute of Transportation Studies found that required parking makes up 31 to 39 percent of construction costs on office and retail projects. The same analysis found parking minimums can drive total office construction costs 47 to 68 percent higher. Figures at that scale reshape a pro forma rather than nudge it.
The lever that moves both numbers is the size of the footprint itself, treated as a design variable rather than a fixed input. Matching ratios to real demand is often the first gain. Shared parking across uses with offset peaks recovers more. Reworking circulation and stall geometry frees up space on tighter sites. Structured and automated systems earn their place where land is genuinely scarce. On plenty of sites, one of the simpler moves does the job better. The real work is reading the site and choosing the setup it calls for.
Parking is one of the few places where the carbon math and the budget math pull the same way. Trim an oversupplied footprint and both come down together, a result the policy findings and the cost studies keep pointing to. Most sustainability measures ask a developer to spend more for a greener result, so an option that lowers both deserves attention on the economics alone.
Disclosure frameworks are advancing toward embodied carbon faster than most development timelines assume. The World Green Building Council projects that upfront carbon will make up about half the total footprint of new construction between now and 2050. A share that size does not stay optional for long.
Building codes are already closing in on the relevant materials. A growing set of jurisdictions now requires environmental product declarations and global warming potential limits on concrete, reinforcing bar, and structural steel, with Denver among the cities writing that language into its codes. Every one of those materials exists in the garage.
Extend that trajectory and the parking structure falls inside whole-building lifecycle assessment and ESG disclosure well within the service life of anything breaking ground now. A developer who measured the garage early arrives at that reporting with the numbers already in hand. A developer who kept it out of the model gets to reconstruct it after the fact, under rules someone else set, and against a deadline.
The garage escaped the audit for so long because of how teams filed it, never because it was small. It carries the most carbon-intensive materials on the project and sits among the heaviest lines in the budget, and its regulatory profile climbs a little higher every year. What makes it worth a fresh look is the rare alignment it offers, a place where the carbon call and the cost call can point in the same direction.
On the projects where I've watched teams weigh footprint against program, the ones who got it right put the structure in the model. Everything downstream, the carbon number, the budget line, the readiness for whatever the code demands next, followed from measuring it instead of waving it through. Run the garage through the same audit as every other system, and the line item that used to slip through becomes one of the clearer decisions on the project.
Christopher Tiessen is President/CEO of KLAUS Multiparking America, which builds space-efficient automated parking systems. He writes and advises on how parking structures factor into embodied carbon and project budgets.
