Loading NuWatt Energy...
We use your location to provide localized solar offers and incentives.
We serve MA, NH, CT, RI, ME, VT, NJ, PA, and TX
Loading NuWatt Energy...
NuWatt designs, installs, and manages solar, battery, heat pump, and EV charger systems across 9 states. One company, one warranty, one point of contact.
Get a Free QuoteIRC §179D rewards Connecticut owners — and the designers of tax-exempt buildings — for efficiency work that pushes a building 25% or more past the ASHRAE 90.1 baseline on HVAC, lighting, and envelope. With Connecticut’s heating-driven loads and older Hartford, New Haven, and Fairfield County stock, a single cold-climate heat pump conversion routinely clears that 25% line by itself. Run a 100,000 sq ft project that began construction by June 30, 2026 can use the 2026 rates; at the PWA cap, an 80,000 sq ft project can produce roughly $100k of federal tax value at a 21% corporate rate.
$5.94
Max PWA /sq ft (2026)
25%
Min Savings vs ASHRAE
5×
PWA Multiplier
3
Qualifying System Types
TL;DR: §179D is now available only for qualifying property whose construction began by June 30, 2026; property starting later is ineligible. Earlier-start projects still must document HVAC, lighting, hot-water, or envelope upgrades that beat the applicable ASHRAE 90.1 baseline by at least 25%. CT’s cold climate makes heat pump retrofits especially high-value, and the 2022 CT State Building Code already drives the energy modeling §179D requires. Owners claim directly; A/E designers claim on UConn, CSCU, Yale New Haven Health, Hartford HealthCare, CT DAS, and town DPW / school district work.
Section 179D of the Internal Revenue Code is a federal tax deduction for energy-efficient commercial building property. Originally enacted in the Energy Policy Act of 2005, it was substantially expanded by the Inflation Reduction Act of 2022 — which raised the deduction ceiling, added a 5× bonus for prevailing-wage and apprenticeship compliance, and extended the designer allocation to cover tax-exempt building owners.
The One Big Beautiful Bill Act (signed July 4, 2025) reshaped the federal energy tax landscape. Residential solar (§25D) and residential heat pumps (§25C) are gone. The commercial ITC (§48/§48E) remains: projects that began construction on or before July 4, 2026 locked in the longer placed-in-service pathway (through roughly 2030), while projects that begin construction after that date can still qualify but generally must be placed in service by December 31, 2027.
Section §179D was terminated for property whose construction begins after June 30, 2026. Earlier-start projects may still qualify when they satisfy the remaining energy-savings, certification, allocation, PWA, and filing rules. Later-start projects should carry $0 of §179D value in the pro forma.
Source of truth: IRS Form 7205 instructions (June 30, 2026 construction-start termination), Rev. Proc. 2025-45 (2026 indexed rates), IRC §179D, and Treasury PWA guidance.
The §179D rate schedule is set by federal law and indexed for inflation annually — it is identical in Connecticut, Texas, and every other state. For qualifying property that began construction by June 30, 2026, the 2026 base range is $0.59–$1.19/sq ft; meeting the prevailing-wage-and-apprenticeship standard moves the range to $2.97–$5.94/sq ft. The table below shows the four inflation-indexed years. For the full federal mechanics of how the deduction is computed, certified, and claimed, see our deeper §179D federal mechanics walkthrough — this Connecticut page focuses on the state-specific context.
| Year | Base Rate Range | PWA Rate Range | Per-Point Bonus (Base / PWA) |
|---|---|---|---|
| 2023 | $0.54–$1.07/sf | $2.68–$5.36/sf | $0.02 / $0.10 |
| 2024 | $0.57–$1.13/sf | $2.83–$5.65/sf | $0.02 / $0.11 |
| 2025 | $0.58–$1.16/sf | $2.90–$5.81/sf | $0.02 / $0.12 |
| 2026current | $0.59–$1.19/sf | $2.97–$5.94/sf | $0.02 / $0.12 |
The deduction climbs in a straight line above the 25% floor — $0.02/sq ft (base) or $0.12/sq ft (PWA) for every additional point of modeled savings, topping out at the applicable 2026 caps. Because Connecticut’s heating-dominated retrofits routinely model in the 35–50% range once a boiler is swapped for a cold-climate heat pump, most CT projects land in the right half of this grid rather than at the entry tier.
25% Savings
$0.59/sf
$2.97/sf PWA
30% Savings
$0.69/sf
$3.57/sf PWA
40% Savings
$0.89/sf
$4.77/sf PWA
50% Savings
$1.09/sf
$5.94/sf (cap) PWA
§179D covers three categories of commercial building property. A single project can qualify under one or a combination — and the energy model aggregates savings across all three. In Connecticut, HVAC is usually the biggest single lever because of the heating load.
Commercial cold-climate heat pumps, VRF systems, high-efficiency chillers, heat recovery ventilation, demand-controlled ventilation, and heat pump water heaters. This is the single highest-leverage §179D category in Connecticut — the state is heating-dominated, so swapping gas or oil boilers for cold-climate heat pumps or VRF almost always clears the 25% energy-savings threshold by itself, and frequently pushes into the 40–50% savings band in the Hartford, New Haven, and Fairfield County commercial stock.
Examples NuWatt Installs in CT
Networked LED retrofits with daylight harvesting and occupancy sensing. In Connecticut, lighting is often the cheapest first move toward the 25% §179D floor in pre-2000 stock — and the work frequently arrives already part-funded, because Energize CT, delivered through Eversource CT and United Illuminating small-business and custom programs, rebates much of the hardware. §179D then captures the federal deduction on top of an in-state rebate the owner has already banked.
Examples NuWatt Installs in CT
Roof and wall insulation, high-performance glazing, air sealing, and high-R roof membranes. The 2022 CT State Building Code (2021 IECC with Connecticut amendments) already raises the envelope bar on new work; on retrofits of Connecticut’s older inventory, tightening the envelope alongside a heat pump conversion is usually the step that carries the energy model past 40% savings and into the upper §179D rate bracket.
Examples NuWatt Installs in CT
Connecticut heating degree days are roughly 2–3× those of major Sun Belt markets. That means heating is the dominant energy-use category in most CT commercial buildings — and when the retrofit replaces a gas or oil boiler with a cold-climate heat pump, the energy-model delta is enormous. It is not unusual for a Hartford office tower, a Bridgeport manufacturing plant, or a Waterbury warehouse to clear 40% savings on HVAC scope alone, which anchors the deduction in the upper tier of the §179D rate range.
Connecticut adopted the 2021 IECC with Connecticut amendments as part of the 2022 CT State Building Code, which requires whole-building energy modeling on most commercial new construction and many substantial alterations. The input data, zone definitions, equipment schedules, and simulation software eligible for IECC compliance (DOE-approved engines such as EnergyPlus / eQUEST / IES-VE) are the same set that satisfy the §179D ASHRAE 90.1 comparison. For design teams already doing CT code-compliance modeling, the incremental labor to produce the §179D certification package is typically a fraction of the value of the deduction — which is why we recommend wiring §179D into the workflow at schematic design, not treating it as a post-construction afterthought.
Federal law names four categories of claimant. In Connecticut the most overlooked is the third — the designer of a tax-exempt building — which, for an A/E firm carrying a UConn, CSCU, state-agency, hospital, or school-district practice, becomes a tax asset that recurs with every qualifying project rather than a one-time benefit.
Owners of Connecticut commercial buildings that place qualifying property in service can claim §179D directly on their federal return. The deduction reduces taxable income in the year the property is placed in service (subject to the capitalization rules for the property). For CT owners, this stacks on top of any state incentives and utility rebates already captured through Energize CT, the CT Green Bank, and C-PACE financing.
Since January 1, 2023, designers of energy-efficient commercial building property installed in buildings owned by tax-exempt entities can have the §179D deduction allocated to them. In Connecticut, that includes work for the UConn system, the Connecticut State Colleges and Universities (CSCU) system, Yale New Haven Health and Hartford HealthCare, the CT Department of Administrative Services portfolio, every town DPW and school district, and the full set of §501(c)(3) nonprofit hospitals, independent schools, and universities across the state.
Architects, engineers, contractors, and design-build firms that design energy-efficient systems for federal, State of Connecticut, county, city, or public-school buildings in CT can receive an allocation of §179D from the government owner. This is a recurring tax asset for A/E firms working on Hartford, New Haven, Stamford, Bridgeport, Waterbury, Norwalk, and regional school district projects.
Tenants that place qualifying property in service (typically during a tenant build-out or significant leasehold improvement in a Stamford financial tower, Hartford downtown office, or New Haven life-sciences space) may claim §179D if they are the party that owns the property for tax purposes. Ownership analysis matters — the lease structure determines who can deduct, and in the New Haven / Science Park lab market and the Stamford corporate corridor this is frequently worth a proactive review.
The Designer Allocation Play for Connecticut A/E Firms
Connecticut concentrates an unusual amount of tax-exempt commercial square footage into a small geographic footprint: the UConn system (Storrs, UConn Health in Farmington, and the regional campuses in Stamford, Hartford, Avery Point, and Waterbury); the Connecticut State Colleges and Universities (CSCU) system; State of CT agency portfolios under the CT Department of Administrative Services; every municipal school district; dozens of major §501(c)(3) hospital and research systems including Yale New Haven Health, Hartford HealthCare, Nuvance, and Trinity Health Of New England; plus private tax-exempt universities led by Yale and Wesleyan. All of these entities have no federal income tax liability to offset with §179D — before 2023, the deduction simply went unused on those projects.
The 2023 change lets the exempt owner sign that unused deduction over to the firm that designed the energy-efficient property. Across a Connecticut design practice — UConn cold-climate HVAC work, a CSCU campus envelope package, a Yale New Haven Health lighting retrofit, a Hartford-area town DPW upgrade — those allocations compound into six-figure recurring deductions over a portfolio.
NuWatt plays the build-and-document role on these jobs: we install the systems, produce the energy model, and hand the A/E firm the certification package it needs to secure the allocation letter from the UConn, CT DAS, hospital, or municipal signatory.
UConn Storrs, UConn Health Farmington, and the regional campuses; plus Central, Eastern, Southern, and Western Connecticut State Universities and the CT community college network. HVAC modernization, lab retrofits, residence-hall heat pump conversions, and envelope upgrades are ongoing designer-allocation opportunities.
The CT Department of Administrative Services manages the Commonwealth-owned portfolio; every town DPW owns municipal buildings; every school district from Hartford, New Haven, Bridgeport, Stamford, Waterbury, Norwalk, and Danbury down to every regional K-12 agency can allocate §179D on HVAC and lighting work.
Yale New Haven Health (flagship Yale New Haven Hospital, Bridgeport Hospital, Greenwich Hospital, Lawrence + Memorial), Hartford HealthCare (Hartford Hospital, MidState, Backus, Windham, St. Vincent’s), Nuvance Health (Danbury, Norwalk, Sharon, New Milford), and Trinity Health Of New England. All are §501(c)(3) tax-exempt and can allocate §179D to the design team.
The deduction value depends on three things: square footage, the achieved energy savings percentage, and whether PWA requirements were met. Corporate tax rate converts the deduction into cash (21% federal corporate rate shown).
Numbers below are illustrative and modeled on typical Connecticut project profiles. Actual values depend on verified energy modeling, certification by a qualified engineer, and final audit posture.
Energy Savings
40% below ASHRAE 90.1
Base (No PWA)
PWA Compliant
Energy Savings
30% below ASHRAE 90.1
Base (No PWA)
PWA Compliant
Energy Savings
50% below ASHRAE 90.1
Base (No PWA)
PWA Compliant
Energy Savings
35% below ASHRAE 90.1
Base (No PWA)
PWA Compliant
The PWA Math Almost Always Wins in CT
The base → PWA jump is roughly 5×. On the Bridgeport cold storage example above, PWA compliance moves the tax benefit from $19,488 to $97,608— a $78k swing. In Connecticut, most public-sector commercial work above statutory thresholds already falls under CT state prevailing wage (Conn. Gen. Stat. §31-53), and the state’s registered apprenticeship infrastructure across Hartford, New Haven, and Fairfield counties makes hour compliance straightforward. The federal §179D PWA boost is typically a near-free add-on compared to greenfield right-to-work states. Plan for PWA compliance as the default, not the exception.
There are two federal paths. The new-construction path (EECBP) measures savings against an ASHRAE 90.1 reference building and has no building-age requirement; the retrofit path (EEBRP) measures savings against the building’s own pre-retrofit baseline and requires the building to have been in service at least five years. The mechanical differences — reference-building vs before/after modeling, the qualified retrofit plan, the baseline-EUI measurement, and the M&V documentation — are covered in full on our federal §179D walkthrough. What matters for Connecticut is which path you will actually use, and why.
The Connecticut commercial stock skews old — much of the inventory in Hartford, New Haven, Bridgeport, Waterbury, and New London pre-dates 2000, so essentially every existing-building project clears the five-year EEBRP age test on day one. That makes the before/after retrofit baseline the more common framework, and it is the more forgiving one: an inefficient 1970s or 1980s building has a high pre-retrofit EUI, so a cold-climate heat pump conversion plus an LED and envelope package frequently models a 35–50% reduction against that baseline.
New construction and gut-renovation work runs the reference-building path instead — and here Connecticut gets a workflow break: the 2022 CT State Building Code (2021 IECC with Connecticut amendments) already mandates whole-building energy modeling on most commercial new builds, so the ASHRAE 90.1 comparison §179D needs is largely produced as a byproduct of code compliance rather than as standalone work.
The 5× multiplier requires two things: paying every laborer and mechanic at or above the Davis-Bacon prevailing wage for the locality and trade, and having a minimum share of labor hours performed by registered apprentices. The federal nuts and bolts — DOL rate lookups, the journeyworker-to-apprentice ratio, the good-faith-effort exception, and the five-year alteration window — are detailed on our federal §179D walkthrough. Connecticut’s distinct advantage is that you are usually most of the way there before §179D enters the conversation.
Connecticut public and institutional construction above the statutory thresholds already runs on state prevailing wage under Conn. Gen. Stat. §31-53, so on the UConn, CSCU, CT DAS, town DPW, and school-district work where §179D’s designer allocation is most valuable, the prevailing-wage discipline is a pre-existing condition rather than a new requirement. On the apprenticeship leg, the CT building trades operate registered programs across sheet metal, electrical (IBEW Local 35 and Local 90), plumbing, pipefitting, and carpentry in Hartford, New Haven, Fairfield, and New London counties — so sourcing qualified apprentice hours is rarely the binding constraint here, unlike right-to-work states. The real work in Connecticut is documentation: certified weekly payrolls, apprentice-hour logs, and classification evidence the IRS can audit.
Compared to right-to-work states, Connecticut is well-positioned for PWA compliance. Most commercial public work above CT statutory thresholds already runs on state prevailing wage under Conn. Gen. Stat. §31-53, and the CT building trades operate a network of registered apprenticeship programs across sheet metal, electrical (IBEW Local 35 and Local 90), plumbing, pipefitting, and carpentry. Key nuance: the CT state prevailing-wage thresholds and rate schedules are not identical to the federal Davis-Bacon determinations used for §179D PWA, so you cannot assume satisfying CT state law automatically satisfies the federal standard. Run both rate tables in parallel during bid and certified payroll — the higher of the two governs each classification. The incremental work is documentation discipline, not behavior change.
A whole-building Connecticut project usually touches all three federal tax tools at once. They land on different line items and never double-count: the solar and storage hardware feeds §48E and MACRS, while the heat pump, lighting, and envelope scope feeds §179D. What makes Connecticut distinctive is the in-state layer that sits on top — Energize CT, the NRES tariff, and the Energy Storage Solutions (ESS) program — which is where most CT-specific value is captured.
A dollar-for-dollar federal credit on the solar-plus-storage cost basis — 30% base, reaching up to 50% with the domestic-content and energy-community adders. Timing has a fork: projects that started construction by July 4, 2026 kept the longest placed-in-service runway; projects starting now place in service by December 31, 2027.
A federal deduction worth up to $5.94/sq ft (2026 PWA rate) against the efficiency line items — the cold-climate heat pump plant, the LED retrofit, and the roof/envelope work. It lowers taxable income rather than tax owed, so the cash it returns is your marginal rate times the per-square-foot amount.
Five-year accelerated depreciation on the solar-plus-storage basis, now paired with 100% first-year bonus depreciation made permanent by OBBBA under IRC §168(k). It runs independently of §48E and §179D — a third, separately-claimed layer of the federal economics.
Combined effect on a typical CT commercial retrofit: the federal stack alone can pull effective out-of-pocket cost down to roughly 40–55% of gross capex. On top of that, Connecticut adds its own programs: Energize CT custom commercial incentives (administered through Eversource CT and United Illuminating) for the HVAC, envelope, and lighting scope; the Non-Residential Renewable Energy Solutions (NRES) tariff, which sets the long-term compensation for the solar generation; and the Energy Storage Solutions (ESS) incentive for the battery. CT Green Bank financing and C-PACE cover the cash-flow gap. None of those state layers exists in a no-incentive state like Texas — they are specific to operating in Connecticut.
Project scope
500 kW rooftop solar + 500 kWh storage + cold-climate VRF + LED + envelope
§48E ITC (solar + storage basis ≈ $1.3M)
30% base + 10% domestic content = 40% of $1.3M
§179D (40% energy savings, PWA)
100,000 sq ft × $4.77/sf deduction × 21% corp rate; eligible pre-cutoff project
MACRS 5-year on solar + storage ($1.3M basis, reduced by 50% of §48E)
NPV of accelerated depreciation at 21% corp rate, 8% discount
Total federal tax stack
~$834k (≈ 24% of gross capex)Illustrative — actual values depend on verified energy modeling, domestic content documentation, depreciable basis calculations, and CT state / Energize CT / CT Green Bank layers on top.
NuWatt delivers the install and the energy model that hold up a defensible §179D claim on Connecticut HVAC, lighting, and envelope work. Whether you own a Hartford office building, lease a New Haven medical suite, or design for UConn, CSCU, CT DAS, Yale New Haven Health, or a town DPW, we will scope the eligibility route and run the PWA documentation with you — and line it up against the Energize CT, NRES, and ESS layers.
§179D is unavailable for property whose construction began after June 30, 2026. Earlier-start projects require project-specific tax review before any value is included.
Last verified: July 9, 2026
Sources: IRS Form 7205 instructions, Rev. Proc. 2025-45, IRC §179D, Treasury PWA guidance, ASHRAE 90.1-2019, 2022 CT State Building Code (2021 IECC + CT amendments), Conn. Gen. Stat. §31-53