ASUENE Blog

Article Details

U.S. Energy Codes and Impact on Green Construction

Construction Insights US
U.S. Energy Codes and Impact on Green Construction
Article Summary

Introduction

The built environment accounts for nearly 40% of total energy consumption in the United States and a significant portion of greenhouse gas (GHG) emissions. As the U.S. accelerates its climate and decarbonization goals, building energy codes have become a foundational policy tool for achieving long-term sustainability in the construction sector.

From federally influenced standards to state-mandated codes, energy efficiency regulations are shaping how buildings are designed, constructed, and operated. This article explores the major energy codes—particularly ASHRAE 90.1 and the International Energy Conservation Code (IECC)—and their growing influence on green construction and ESG integration.


What Are Building Energy Codes?

Building energy codes are legal minimum requirements that govern energy use in the design and construction of buildings. They typically address:

  • Envelope performance (insulation, windows, doors)
  • Mechanical systems (HVAC, fans, chillers)
  • Lighting systems (fixtures, daylighting, controls)
  • Water heating and energy distribution

These codes exist to ensure that new buildings meet a baseline of energy efficiency and climate responsiveness. They are updated periodically to reflect technological advances, climate data, and emission reduction targets.


ASHRAE 90.1 and the IECC

ASHRAE Standard 90.1

Developed by the American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE), 90.1 is a reference standard for commercial buildings used in:

  • Federal buildings
  • LEED certification (as a baseline)
  • Many state and local building codes

International Energy Conservation Code (IECC)

Managed by the International Code Council (ICC), the IECC is adopted widely across U.S. states and:

  • Covers both residential and commercial buildings
  • Is updated every 3 years
  • Allows performance-based and prescriptive compliance paths

Together, ASHRAE 90.1 and the IECC form the backbone of U.S. energy building regulations.


The Rise of State-Level Code Adoption

While building energy codes are developed at the national level, their adoption is left to state and local governments. Over time, a growing number of states have implemented updated versions of IECC and ASHRAE, advancing national energy performance.

Figure 1: State Adoption of Building Energy Codes (2010–2022)

As of 2022, 44 states have adopted a version of the IECC, and 35 states have adopted ASHRAE 90.1 or equivalent standards. This widespread adoption reflects increasing momentum toward energy-aligned construction nationwide.


ESG Implications for the Construction and Real Estate Sectors

Building energy codes are no longer just compliance checklists—they have become strategic ESG tools:

ESG PillarImpact of Energy Codes
EnvironmentalReduce energy consumption, improve thermal efficiency, and cut Scope 1 & 2 emissions
SocialEnhance occupant comfort, indoor air quality, and long-term health outcomes
GovernanceDemonstrate regulatory compliance and due diligence in ESG disclosures (e.g., GRESB, CDP, SASB)

Case Studies

1. PNC Tower – Pittsburgh, PA

PNC’s headquarters was designed to meet ASHRAE 90.1 and IECC standards, using advanced façade systems, radiant heating, and passive ventilation. It consumes 50% less energy than typical office buildings.

2. The Bullitt Center – Seattle, WA

Often cited as the “greenest commercial building in the U.S.,” the Bullitt Center exceeds local codes by integrating net-zero energy design, triple-glazed windows, solar panels, and rainwater harvesting.

3. Sacramento Housing Redevelopment

Through California’s adoption of Title 24 (an enhanced version of IECC), this public housing project achieved over 30% energy savings through code-mandated insulation, lighting, and HVAC upgrades.


Role in Green Building Certifications

Many sustainability certifications require or build upon code compliance:

CertificationCode Linkage
LEEDUses ASHRAE 90.1 as the baseline for energy performance prerequisites
ENERGY STAR for BuildingsAssumes code-compliant construction as a baseline
WELL Building StandardRequires code-level HVAC and lighting minimums
Green GlobesAligns with both IECC and ASHRAE compliance pathways

Achieving or exceeding code standards not only ensures compliance but also facilitates certification, boosting property value and ESG ratings.


Financial and Policy Incentives

Many states and municipalities offer incentives for exceeding code requirements, such as:

  • Density bonuses for developers
  • Tax abatements for green building features
  • Accelerated permitting for high-efficiency projects

Additionally, the Inflation Reduction Act (2022) includes funding for local governments to adopt and enforce advanced energy codes, helping accelerate the transition.


Challenges in Implementation

ChallengeSolution
Complexity of modeling complianceUse certified energy modelers and software (e.g., EnergyPlus, eQuest)
Cost perceptionHighlight lifecycle energy savings and improved tenant retention
Fragmented code enforcementWork with local building departments early in the design phase
Resistance to changeOffer training to contractors and design teams on code benefits

By proactively engaging stakeholders and using available technical resources, developers can turn code compliance into competitive advantage.


The Future of Energy Codes

The future of building energy codes is increasingly integrated with carbon reduction, climate resilience, and smart technology. Key trends include:

  • Carbon-based codes: Shifting from energy to GHG-based performance metrics
  • Grid-interactive buildings: Integration with demand response and storage
  • Embodied carbon regulation: Expanding scope to include construction materials
  • Climate zone-specific codes: Tailoring requirements to regional environmental realities

These advancements will play a key role in meeting U.S. commitments under the Paris Agreement and emerging SEC climate disclosure requirements.


Conclusion

Energy codes like ASHRAE 90.1 and the IECC are essential tools for building a low-carbon future. Far from being mere regulations, they:

  • Drive innovation in architecture and engineering
  • Lower long-term operational costs
  • Strengthen ESG profiles for investors and stakeholders

For construction firms, developers, real estate investment trusts (REITs), and ESG managers, staying ahead of code updates and leveraging them strategically is vital to ensuring that the buildings we construct today remain sustainable, compliant, and valuable tomorrow.

Download Our Expert Publications!

Why Work with ASUENE Inc.?

ASUENE USA Inc., a subsidiary of Asuene Inc., is a key player in carbon accounting, offering a comprehensive platform that measures, reduces, and reports emissions, including Scope 1-3, with expertise in decarbonization and GRI compliance. Asuene serves over 10,000 clients worldwide, providing an all-in-one solution that integrates GHG accounting, ESG supply chain management, a Carbon Credit exchange platform, and third-party verification. With a strong focus on the manufacturing and construction sectors, ASUENE supports companies in achieving net-zero goals through adva

Talk to us

For any inquiries regarding our products or partnerships, please feel free to contact us. Connect with our team today
and begin your journey to net zero.