IECC Commissioning-What You Need to Know to Stay Compliant in Illinois

If you're planning a commercial construction or renovation project in Illinois, there's one critical question you need to ask: Does your project require third-party commissioning under the Illinois Energy Conservation Code (IECC)?

If your answer is “yes” to any of the following, then the 2021 IECC likely applies to you:

• Your cooling system exceeds 40 tons of capacity.
• Your heating system is rated over 600 MBh.
• You’re working on a large-scale commercial building.
• You manage energy-intensive facilities like hospitals, schools, or data centers.
• You’re upgrading HVAC systems in a complex mechanical environment.
• You’re responsible for code compliance on a multi-tenant property.

Let’s break down what this means—and how to stay compliant without the headaches.

What Changed with the 2021 IECC in Illinois?

As of January 1, 2024, Illinois adopted the 2021 International Energy Conservation Code, introducing stricter energy efficiency standards for mechanical systems in commercial buildings.

But don’t worry—compliance doesn’t have to be complicated. Whether you’re a contractor, engineer, building owner, or facilities manager, understanding the new rules can help you avoid costly delays and ensure your systems perform as intended.

When Is Third-Party Commissioning Required?

Under the 2021 IECC, commissioning is mandatory when:

• Cooling systems have a total mechanical capacity over 480,000 Btu/h (140.7 kW) — that’s 40 tons.
• Heating systems (including space and service water heating) exceed 600,000 Btu/h (175.8 kW).

Why Commissioning Matters

Commissioning isn’t just a regulatory checkbox—it’s a quality assurance process that ensures your mechanical systems are:

• Properly designed
• Correctly installed
• Functioning as intended

It’s about optimizing performance from day one, not just passing inspection.

Who Performs the Commissioning?

A qualified third-party commissioning provider (like Aero Performance Group) works alongside your project team to:

• Validate system performance
• Document compliance for code officials
• Identify and resolve issues early

The Benefits of Expert Commissioning

Partnering with a commissioning expert delivers more than just compliance:

• Peace of Mind: Confidence that your systems meet code and perform reliably.
• Energy Savings: Efficient systems reduce utility costs and carbon footprint.
• Problem Prevention: Catching issues during construction avoids expensive fixes later.

Let’s Talk About Your Project

Every building is different—and so are its commissioning needs. Whether you're breaking ground on a new facility or retrofitting an existing one, Aero Performance Group is here to help you navigate the IECC requirements with confidence.

Have questions about compliance or commissioning?
Let’s connect and make sure your project is built to perform.