A new piece of legislation is making its way through Congress, and if you own commercial real estate, work in design and construction, or advise clients who do, it’s worth paying attention.
On April 23, 2026, Representative Brian Fitzpatrick (R-PA) introduced H.R. 8477, the American Energy Dominance Act. The bill, which has bipartisan support, includes a provision that would restore Section 179D as a permanent tax incentive, removing the sunset provisions that currently limit its runway.
What’s Currently on the Table
Under existing law, Section 179D allows commercial building owners and certain designers, including architects and engineers working on government-owned properties, to take an immediate deduction for qualifying energy-efficient improvements. Depending on the level of energy performance achieved and whether prevailing wage requirements are met, deductions can range from $0.50 to $5.81 per square foot. That’s a meaningful benefit for any project of significant scale.
However, recent legislative changes under Public Law 119-21 (commonly referenced as the “One Big Beautiful Bill”) introduced modifications to several energy-related tax provisions, including 179D and the Section 45L new energy-efficient home credit. H.R. 8477 would reverse certain of those changes and, critically, would restore 179D as a permanent incentive rather than a time-limited one. The bill would also extend Section 45L through December 31, 2032.
What This Means, and What It Doesn’t
This is encouraging news for anyone who values energy-based tax incentives. Growing legislative momentum around 179D permanence signals that Congress recognizes the value of keeping this incentive in place for the long term.
That said, H.R. 8477 is still early-stage legislation. It has not been enacted into law, and current law remains in effect today. Under current rules, Section 179D is available for buildings already placed in service or for projects that begin construction by June 30, 2026.
This distinction matters. Waiting to see how the bill progresses is not a risk-free strategy. Here’s why:
- If your project is already complete or underway, the window to claim 179D under current law is real and finite. A favorable legislative outcome later does not retroactively fix missed filing deadlines or incomplete documentation.
- The 179D deduction requires a certification study conducted by a qualified engineer using IRS-approved energy modeling software. That documentation takes time to assemble and must be in place to support the claim.
- For architect and engineering firms receiving allocated deductions from government-owned building projects, allocation letters and certifications must be obtained before project teams disperse, another reason not to delay.
The Smart Move Right Now
Whether or not H.R. 8477 advances, the most defensible position for taxpayers and their advisors is to act on current-law opportunities now and build clean, audit-ready files in the process. If permanence is ultimately restored, those same clients will be best positioned to capture benefits across future projects without scrambling to reconstruct documentation.
At CSSI, our approach to 179D has always been grounded in engineering rigor and compliance-first methodology. We conduct the energy modeling, prepare the required certifications, and deliver studies designed to hold up under IRS scrutiny, not just maximize a number on a form.
For CPA and Referral Partners
If you have clients with commercial construction, renovation, or government-building design projects completed in recent years or currently underway, now is the time to surface the 179D conversation. The legislation reinforces that this is an area of growing policy priority, and clients who move early, with proper documentation in place, will be in the strongest position regardless of how the legislative landscape evolves. Contact CSSI today to get started.
Calculate how much you could save with our Section 179D Calculator!
