Until June 30, a production builder in Climate Zone 5 could spend $3,200 upgrading a spec home from code-minimum insulation and a standard heat pump to Energy Star certification and collect a $5,000 tax credit under Section 45L of the Internal Revenue Code, netting $1,800 per home. On a 200-unit subdivision, that is $360,000 in free money for building slightly better houses.
On July 1, the credit vanished.
Signed by President Trump on July 4, 2025, the One Big Beautiful Bill Act terminated 45L along with every other major residential energy tax credit created or extended by the Inflation Reduction Act. Congress had originally pushed 45L’s expiration out to December 31, 2032 under the IRA, giving builders eight years of runway, but the OBBB clawed six of those years back, setting a hard cutoff of June 30, 2026, for any home not yet acquired by its first buyer.
Builders knew this was coming, and they had twelve months of lead time, but that does not make the math easier now that the deadline has passed and no replacement exists.
What Died and When
Congress did not surgically remove one credit. It cleared the table.
| Credit | What It Covered | Expiration |
|---|---|---|
| 45L | Builder credit, up to $5,000/home for Energy Star or ZERH | June 30, 2026 |
| 25C | Homeowner credit, up to $3,200/year for windows, insulation, HVAC | Dec 31, 2025 |
| 25D | 30% credit for residential solar, geothermal, battery storage | Dec 31, 2025 |
| 30C | EV charger installation credit | June 30, 2026 |
| 179D | Commercial building energy efficiency deduction | June 30, 2026 |
An NAHB summary of the OBBB changes notes that an executive order dated July 7, 2025, directed the Treasury Department to “strictly enforce” all credit terminations. NAHB warns that taxpayers should expect the IRS to interpret the acquisition date narrowly, requiring legal title transfer before July 1 regardless of when construction started or when Energy Star certification was issued. A home that broke ground in 2024, earned its HERS rating in March, and sits on the market in July is worth $5,000 less to the builder than it was thirty days ago.
Builder Math Without the Credit
Building to Energy Star adds roughly $2,000 to $4,000 in incremental construction cost over code minimum, depending on climate zone, according to ACEEE’s 45L fact sheet. For a DOE Zero Energy Ready Home, the premium runs $5,000 to $15,000. Previously, the credit covered most or all of the Energy Star increment, but without it every dollar of green premium comes out of the builder’s margin or gets added to the sale price.
That sale price is already under extraordinary pressure. According to the NAHB’s 2026 regulatory cost study, regulations now add $131,734 to the average new home, representing 26.4 percent of a $499,500 sale price, with regulatory costs increasing 40 percent over five years while disposable income rose only 18.3 percent.
A builder absorbing $131,734 in mandatory regulatory costs and watching diesel prices climb 105.9 percent year-over-year (per BLS PPI data tracked by NAHB) is not going to voluntarily add $3,000 for an Energy Star upgrade that used to be free, not unless someone is paying for it, and right now nobody is.
Buyer Math Still Works. Barely.
From the buyer’s side, the numbers tell a different story. An Energy Star home saves $400 to $500 a year on utility bills; a ZERH home saves $1,000 or more. ACEEE’s analysis found that discounted lifetime energy savings from 45L-eligible homes were four times the cost of the credit to the Treasury, meaning the program worked by any reasonable benefit-cost ratio.
But homebuyers do not purchase present-value calculations — they buy monthly payments. A $3,000 bump in sale price adds roughly $20 a month to a 30-year mortgage at 6.5 percent interest, while the energy savings might reduce the utility bill by $35 to $40, yielding a net gain of $15 to $20 a month. Positive, but not the kind of number that moves a purchasing decision when a family is already stretching to qualify.
What Fills the Vacuum
State programs and rising code minimums could partially replace the federal incentive, but neither fills the specific hole that 45L filled: a uniform national incentive rewarding builders for exceeding local code by a standardized threshold.
Arizona’s Salt River Project still offers per-kWh rebates for efficient new construction, and several Northeast states run incentive programs through utility ratepayer funds, but these vary wildly in generosity and administrative burden, and a production builder working across state lines cannot plan a product line around a patchwork of local rebates that might not exist next fiscal year. Meanwhile, the 2024 International Energy Conservation Code will push code minimums toward what Energy Star required in 2022 within two to three years of adoption, but code advancement is uneven: some states still enforce the 2009 IECC.
Market demand may also sustain green building without credits. Industry data shows green-certified homes sell for 2 to 8 percent more than comparable non-certified homes in most markets. A builder who drops Energy Star to save $3,000 in construction cost and loses $10,000 in resale value is not saving money. That argument holds in markets with informed buyers. It dissolves in entry-level markets where the buyer picks the house that costs $3,000 less.
What You Should Do
If you are a production builder who was building to Energy Star with 45L credits: run the margin analysis for your specific product line without the credit. In climate zones 4 through 7, the incremental cost is lowest and the energy savings are highest, and the math may still pencil, particularly if your buyers skew toward the move-up market where resale value and utility costs matter. In climate zones 1 through 3, the case is harder.
If you are a homebuyer under contract on a new build: ask for the HERS score and whether the home qualifies for any remaining state or utility rebates. A HERS score below 55 at median pricing means the builder invested in efficiency regardless of the credit, and you are buying a home that will cost meaningfully less to operate over its lifetime.
If you are watching this from the policy side: the 45L credit cost the Treasury an estimated $1.7 billion over seven years according to Joint Committee on Taxation scoring cited by ACEEE. Dividing by seven yields roughly $240 million per year. ACEEE’s own analysis shows the program returned four times that amount in consumer energy savings. Homes that will not be built to Energy Star as a result will consume the budget savings in excess energy costs within a few years.
Limitations
ACEEE data is from 2024; uptake in 2025–2026 may have spiked or dropped as builders adjusted to the approaching deadline. Incremental cost ranges vary by climate zone, labor market, and builder scale. State replacement programs are in active flux. NAHB’s $131,734 regulatory cost figure includes all regulation, not just energy mandates.