California Proposition 45: What the Election Results Mean for Construction, Environmental Compliance, and Climate Risk

Understanding the implications for developers, contractors, and project owners across California.

UPDATE: Preliminary results indicate Proposition 45 is predicted not to pass. The outcome won't be certain until the Secretary of State certifies results on December 11, 2026. Below, we explain what the measure would have meant and what project teams should plan for either way.

California voters weighed in on Proposition 45 during the November 3, 2026 general election. The measure proposed significant changes to the California Environmental Quality Act (CEQA).

For construction and development professionals, the question is practical: what does this mean for upcoming projects, environmental reviews, permits, and schedules? Here's what project teams should know.

What Would Proposition 45 Have Changed?

Proposition 45 proposed new environmental review and legal challenge procedures for certain development and infrastructure projects. Eligible project types included housing, transportation, water infrastructure, healthcare facilities, educational buildings, clean energy, and wildfire mitigation.

The measure aimed to streamline approvals by:

• Establishing more defined timelines for environmental reviews and permitting decisions.
• Modifying how project alternatives and environmental impacts are evaluated.
• Setting deadlines for legal challenges related to project approvals.
• Changing certain public comment and judicial review procedures.

Supporters emphasized faster project delivery and lower development costs. Opponents raised concerns about reduced environmental oversight and public participation.

What Does the Outcome Mean for Construction Projects?

If preliminary results hold, California's existing CEQA review and legal challenge procedures stay in place, along with other applicable laws and previously enacted reforms. Environmental considerations will continue to shape project planning, approvals, and construction schedules.

If the measure had passed, shorter review timelines would not have reduced the underlying environmental work. Compressed schedules would have made early, well-documented site data even more important, because there would be less time to resolve surprises.

Either way, CEQA is only one part of California's environmental regulatory framework. Requirements for hazardous materials, air quality, stormwater, and worker safety apply independently of CEQA.

The Environmental Compliance and Permitting Angle

CEQA review decides whether a project can be approved; permits decide whether it can be built and operated. Most schedule risk sits in the permits, and none of them would have changed under Proposition 45.

Depending on the site and scope, project teams commonly need to address:

When these are identified late, they can stop work or force redesign. Building them into the schedule during due diligence keeps permitting on the critical path visible instead of surprising.

A Sustainability Lens: Seeing the Full Risk Picture

The Proposition 45 debate centered on speed versus oversight. For owners and investors, a more useful question is how well they understand a site's risks, from the ground up to the long term. Citadel EHS looks at that in three layers:

1. Environmental risk (Environmental Services). What is in the soil, groundwater, soil vapor, and building materials, and what regulatory obligations follow.
2. Human health risk (Industrial Hygiene & Safety). How those conditions could affect the workers who build the project and the people who later occupy it, from vapor intrusion to asbestos, lead, and silica exposure.
3. Climate risk (Sustainability). How physical hazards (heat, wildfire, flooding, drought), regulatory change, and weather-related disruption could affect assets, operations, and value over time.

The third layer increasingly matters beyond individual projects. California's SB 261 requires large companies doing business in the state to publish climate-related financial risk reports covering physical and transition risks. Enforcement has been paused pending a Ninth Circuit appeal (CARB status), but many companies are preparing now so they are ready if the requirement takes effect. Site-level environmental and health data feeds directly into those assessments.

Want to see how these layers apply to your portfolio or next project? Request a risk consultation and our team will follow up within one business day.

How Can Project Teams Minimize Environmental Delays?

Regardless of the final result, identifying environmental issues early helps teams manage schedules, budgets, and regulatory obligations.

1. Evaluate environmental conditions early. Due diligence during site selection, acquisition, and preliminary design surfaces concerns before they affect construction.
2. Map permits to the schedule. Identify stormwater, air, hazardous materials, and cleanup requirements up front, with realistic agency review times built in.
3. Integrate environmental expertise into planning. Early coordination among developers, designers, contractors, and environmental consultants clarifies requirements and mitigation strategies.
4. Maintain a proactive compliance strategy. Monitoring, documentation, and reporting obligations continue through construction and reduce the risk of costly stop-work orders.

How Citadel EHS Can Help

Citadel EHS works with developers, general contractors, architects, engineers, and public agencies across the project lifecycle. Our practices work together so one team can cover the full risk picture.

Looking Ahead

California's environmental and climate regulatory landscape keeps evolving through legislation, agency guidance, and litigation. One principle stays constant: projects succeed when environmental, health, and climate risks are understood early.

Citadel EHS will keep monitoring Proposition 45's certification, CEQA reform, and SB 261 developments, and will update this post as results are finalized.