Stretch Energy Code
Bringing Energy-efficient Buildings to Aurora
The City of Aurora is considering adopting the Illinois Stretch Energy Code for residential and commercial buildings.
Upcoming Events
Passive Building Envelop and HVAC Design Across Building Types
Date: 12/09/2025
12:00 PM
Join us for an in-depth exploration of how Passive House principles can be applied across a wide range of building types—from healthcare facilities and warehouses to schools and manufacturing plants. This program will highlight how passive design strategies can significantly enhance building performance, comfort, and efficiency.
Passive Building Envelope & HVAC Design Webinar
Design & Construction Roundtable
Date: 12/12/2025
11:00 AM - 12:00 PM
Join this one-hour virtual discussion to share your experiences and perspectives as Illinois advances new stretch energy codes. Builders, developers, and construction professionals are invited to weigh in on real-world challenges and opportunities related to stretch code implementation. We are especially interested in discussing how project teams are looking at cost-effective strategies to meet code compliance pathways—and learning how we can best support efficient, resilient building practices across the state.
Illinois Stretch Code: Design & Construction Roundtable
Making it Happen: Implementation Pathways
Date: 12/16/2025
12:00 PM
This session will dive into real-world implementation pathways that turn plans into results, with examples of successful retrofit projects and the partners, tools, and funding strategies that made them possible. Speakers will explore the most common building upgrades, from HVAC electrification and insulation to solar installations, and how to integrate these into capital planning cycles. Learn how to collaborate effectively with contractors, engineers, and financing partners to streamline projects, and hear practical insights on how to unlock incentives, grants, and loans for your next step. Whether you’re preparing for your first major retrofit or scaling up your efforts, this webinar will give you the knowledge, tools, and trusted resources to confidently move from planning to action.
Making It Happen: Implementation Pathways Webinar
What is a stretch code?
A stretch code is an alternative building code that exceeds the minimum performance of available code options (base code). Its purpose is to give communities the option to adopt higher standards for energy efficiency in new buildings and major renovations.
By following the stretch code, buildings use less energy for heating, cooling, and lighting, saving money over time while reducing environmental impacts. Stretch codes can also help accelerate market acceptance of more energy efficient building practices in the future; the name “stretch” comes from the fact that sometimes stretch code requirements are included in future base codes.
What is the Illinois Stretch Energy Code?
The Illinois Stretch Energy Code is developed by the Illinois Capital Development Board and has been available for adoption since January 1, 2025. By statute it is required to meet specific energy conservation targets that are updated every three years through 2032 (when it effectively will meet net-zero energy readiness).
The Illinois Stretch Energy Code is designed to lower long-term operating costs for buildings, improve indoor air quality and occupant health, and help Illinois meet its goals for net-zero carbon emissions by 2050. It is also intended to work with other I-codes and offer flexible choices to meet the energy efficiency targets after meeting the required measures.
Once adopted by a municipality, the stretch code becomes the new minimum standard in that jurisdiction. More detailed information can be found in the Learn More section below.
Why is Aurora considering stretch code adoption?
Aurora is exploring the Illinois Stretch Energy Code as part of our commitment to:
Addressing Cost and Development Concerns
It’s natural to wonder whether building to higher standards means higher housing costs or less future development. Studies in Illinois and across the country show that while energy-efficient construction can add modest upfront costs, these can be offset by monthly energy savings, reduced maintenance needs, and higher property value.
In many cases, any initial increased costs can level out over time as the industry and market adjust to the learning curve. There is also no evidence that stronger energy standards lead to less development, especially when requirements are not overly complicated, and adequate time and resources for education and implementation are provided. Developers who choose stretch code communities aren’t afraid of high standards—they embrace them to deliver durable, efficient, and future-ready buildings that will benefit the community for generations.
The truth is that housing prices and construction costs have continued to rise even in places with no energy codes or weak energy efficiency requirements. Utility prices are also rising, with rates in Illinois increasing an average of 6.8% every year since 2020, and 14% in 2025 (some residents saw triple digit electric bill increases this summer).
Any new construction cannot afford to be built in a way that burdens future occupants with a lifetime of high energy bills. Energy codes are the only building codes where occupants see a direct payback into their pocketbook every month through the life of the building. By adopting the Illinois Stretch Energy Code, our city is not only ensuring smarter buildings for today but also protecting residents from higher costs in the future.
That said, Aurora is committed to understanding the impacts of the stretch code and is exploring ways to assist the industry and homeowners with incentives, education, and technical assistance. See the Get Involved section below if you’d like to participate in providing feedback.
Will support be available?
The City will offer clear guidance, training opportunities, and easy-to-use compliance checklists to help builders and developers meet stretch code standards (some of those checklists and trainings can already be found in the Learn More section below). We’ll work closely with contractors, inspectors, and property owners to make the transition smooth. The City will also connect projects with available incentives, rebates, and technical assistance to help offset costs and simplify the process.
Benefits for Our Community
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Healthier, more comfortable homes and workplaces: Improved ventilation and insulation mean cleaner indoor air, less drafts, and more consistent indoor temperatures
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Future-proof construction: Buildings designed to higher efficiency standards are more durable, maintain their value longer, and avoid costly retrofits in the future
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Economic growth: Energy-efficient construction supports local jobs in building, design, and technology, while lowering the long-term cost of living for residents
Past Events
Illinois Stretch Energy Code Training - Commercial
Date: 10/7/2025
Learn about requirements for the state-developed stretch code aimed at improving building energy efficiency. Register to access the recorded webinar.
Commercial Stretch Code Training
Illinois Stretch Energy Code Training - Residential
Date: 9/30/2025
Learn about requirements for the state-developed stretch code aimed at improving building energy efficiency. Register to access the recorded webinar.
Residential Stretch Code Training
Phius 101: Foundations of Passive Building and Phius Standards
Date: 4/17/2025
Join Illinois Green Alliance and Phius to learn how you can build comfortable, healthy, cost-efficient buildings for a more resilient world at Phius 101 for Architects and Engineers! In Illinois, Phius certification is an alternative compliance path to the base energy code, stretch energy code, and the Chicago Energy Transformation Code, and included in the point structure for the Illinois Qualified Allocation Plan and Chicago Sustainable Development Policy.
Whether you're new to passive building concepts, or looking to deepen your knowledge, this session will provide valuable takeaways and practical guidance to build high performance buildings in Illinois. Presented by Zoe Rader, learn the basics of passive building and get your intro to Phius in this one-hour session.
PHIUS 101: Foundation of Passive Building & Phius Standards
ComEd High Performance Design Incentives
Date: 2/12/2025
Learn about a ComEd program that provides comprehensive energy solutions for new construction and major renovation projects. ComEd New Construction offering makes it easy to design for greater energy savings. It provides solutions that can help your facility generate long-term energy and cost savings. Learn how to push your design further by consulting with experienced technical experts at no cost and receive one-time financial incentives for new construction or major renovations designed to exceed energy code requirements. Major renovations are eligible if including significant beyond-code upgrades to at least two major building systems. Additional funds are available for lead design firms that actively engage with the program. ComEd provide recommendations, assistance, and financial incentives for energy-saving improvements to all major building systems—envelope, HVAC equipment, lighting, commercial refrigeration and more.
ComEd High Performance Design Incentives Webinar
The Illinois Stretch Energy Code Benefits, Adoption, & Implementation
Date: 10/15/2024
Learn about the development process of the Illinois Stretch Energy Code with SEDAC. Justify why and how a jurisdiction might adopt the Stretch Code. Identify how the Stretch Code improves resiliency and reduces pollution. Evaluate key provisions in the Stretch Code that improve performance above the Illinois base Energy Code.
The IL Stretch Energy Code Benefits, Adoption & Implementation Webinar
Get Involved
Aurora is in the process of gathering feedback on stretch code adoption, including hosting opportunities for public feedback and convening a technical Stretch Code Advisory Workgroup. We are committed to understanding the impacts of the stretch code and exploring ways to assist the industry and homeowners with incentives, education, and technical assistance.
If you’d like to get involved or have questions, please send us an email, and continue visiting this site for updates.