Understanding the 45L Tax Credit: A Gateway to Sustainability

Understanding the 45L Tax Credit: A Gateway to Sustainability

The 45L tax credit incentivizes builders and homeowners by offering financial benefits for constructing energy-efficient homes, driving sustainability in the housing sector.

By Abby Massey ・ 5 min read
Industry Insights

What is the 45L Tax Credit?

The 45L tax credit, as part of the Energy Efficient Home Credit under the Internal Revenue Code, is designed to encourage the construction of energy-efficient residential buildings. This credit provides builders and developers with a financial incentive for each dwelling unit that meets certain energy-saving standards. The credit amounts vary, with up to $2,500 for single-family and multifamily homes meeting the ENERGY STAR requirements and up to $5,000 for homes that achieve DOE Zero Energy Ready Home certification​​.

Who Benefits?

The primary beneficiaries of the 45L tax credit are builders and developers of new residential properties. These entities can offset the costs associated with the enhanced energy efficiency measures required to qualify for the credit. Ultimately, the homeowners or tenants also benefit through reduced energy costs and increased comfort levels in their homes​​.

Purpose and Creation of the 45L Tax Credit

The 45L tax credit was created to promote energy conservation in the residential sector, contributing to the broader goal of reducing greenhouse gas emissions. By making energy-efficient homes more financially attractive to build, the credit supports the construction industry while advancing environmental sustainability​​.

Changes Under the Inflation Reduction Act (IRA)

The Inflation Reduction Act has introduced several enhancements to the 45L tax credit, including an increase in the credit amounts through 2032 and ease of qualification by getting ENERGY STAR or DOE Zero Energy Ready Home certified. These changes aim to further incentivize the adoption of energy-efficient home constructions and renovations​​.

Challenges and Considerations

While the 45L tax credit offers significant value, there can be challenges. Builders must navigate complex eligibility requirements such as prevailing wage requirements set out by the Inflation Reduction Act and ensure proper certification through approved third-party assessors. Both certifications require consultation throughout design and construction, so it’s important to plan for these incentives in the early stages of a project.

Ideal Candidates for the 45L Tax Credit

Ideal candidates for this tax credit include builders and developers ready to invest in advanced building technologies and energy-efficient designs. These entities should be prepared to comply with the certification process and any costs associated with prevailing wage requirements and the installation of energy efficient equipment.

Energy-Efficient Buildings that Qualify

  • Residential Condominiums
  • Apartment Buildings
  • Affordable Housing
  • Residential Building Undergoing Major Renovation
  • Student Housing
  • Senior/Assisted Living Facilities 

What is Energy Star? 

Energy Star is a U.S. Environmental Protection Agency (EPA) program designed to promote energy efficiency in various products, homes, buildings, and manufacturing plants. The program provides a recognizable label, the Energy Star certification, which indicates that a product or property meets or exceeds certain energy efficiency standards set by the EPA.

The 45L tax credit and Energy Star work together to promote energy-efficient home construction by providing financial incentives for builders and assurance of lower energy costs for homeowners. This synergy helps push the residential building sector towards more sustainable practices, contributing to broader environmental goals.

How Energy Star Works with the 45L Tax Credit

The 45L tax credit is closely tied to Energy Star in several ways:

  • Certification Requirements:
    • To qualify for the 45L tax credit, newly constructed or substantially renovated homes must meet specific energy efficiency standards. One of the pathways to demonstrate compliance is through achieving Energy Star certification for homes or multifamily buildings.
    • Homes that receive Energy Star certification have been verified to consume less energy compared to non-certified homes, often by significant margins, depending on the local climate and construction practices.
  • Enhanced Credit for Higher Standards:
    • The 45L tax credit provides greater benefits for homes that achieve higher standards of energy efficiency. For instance, homes certified under the Department of Energy's Zero Energy Ready Home (ZERH) program, which includes Energy Star certification as a prerequisite, can qualify for a higher tax credit amount.
  • Verification and Compliance:
    • Energy Star certification involves a third-party verification process conducted by certified Home Energy raters. These raters use approved software to model energy consumption and ensure that the homes meet the stringent requirements of the Energy Star program. This process aligns with the verification needed for the 45L tax credit, making it easier for builders to qualify if they are already pursuing Energy Star certification​​.
  • Market Appeal and Financial Incentives:
    • Beyond energy savings, Energy Star certification can enhance the marketability of homes, aligning with consumer preferences for sustainability and lower operating costs. The 45L tax credit adds a financial incentive for builders, making energy-efficient projects more financially attractive and feasible.
  • Continuous Updates:
    • Energy Star standards are periodically updated to reflect advancements in building technologies and practices. Homes meeting the most current Energy Star standards are likely to qualify for the 45L tax credit, encouraging ongoing improvements in residential energy efficiency​​.

What Qualifies as an Energy Star Certified Home?

  • High-Quality Insulation
  • High-Performance Windows
  • High-Efficiency Heating & Cooling System for Improved Comfort
  • Comprehensive Water Management Techniques That Protect Against Moisture Damage
  • Advanced Air Sealing 


The 45L tax credit plays a crucial role in promoting sustainability in the housing sector. By offsetting the costs associated with energy-efficient construction, it encourages builders to invest in green building practices, benefits the environment, and provides financial relief to homeowners through reduced energy expenses. The recent expansions under the IRA only strengthen its potential impact, making it a pivotal element of the U.S. strategy to combat climate change and promote energy independence.

About the author

Abby Massey
VP of Energy Incentives

Abby Massey is an expert in applying tax incentives for clean energy initiatives. With a B.S. in Civil Engineering from Purdue University and licenses in 47 states plus the District of Columbia, Abby offers significant expertise to her role at TaxTaker as the Vice President of Energy Incentives. Her experience includes certifying over 1,400 179D deductions, achieving more than $100 million in savings for clients. As a LEED Accredited Professional, Abby is dedicated to sustainable building practices. In her role at TaxTaker, she focuses on optimizing energy incentives for clients by leveraging her in-depth understanding of the 179D program, aiming to improve business sustainability and efficiency.

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