If you have claimed 179D with a national firm, you know what an associate-run engagement feels like. We run both 179D and R&D studies partner-to-partner. In-house PE certification coast to coast on the 179D side. Engineer-led technical interviews on the R&D side. One team, both incentives, on the same project.
Dollar-for-dollar federal credit for engineering design work involving technical uncertainty resolved through experimentation. Applies to custom HVAC and lighting design, energy modeling, envelope thermal analysis, BIM-based performance simulation, and proprietary design standard development. Federal credit plus nearly 40 states with additional credits.
Scales with qualifying R&D spend. Wages typically dominate the QRE base for AEC firms.
First-year federal deduction up to $5.94 per square foot for designers of energy-efficient systems on government and tax-exempt building projects. The Inflation Reduction Act expanded eligibility in 2023 to include all 501(c)(3) entities and tribal government buildings.
Prior 3 years plus the current open tax year. Capped at the cost of designer services on the project.
The same project can generate both. The R&D credit applies to the engineering design process. The 179D deduction applies to the energy-efficient systems placed in service. Two separate IRC sections, two separate claims, no conflict between them. Most national tax firms split these into separate engagements with separate teams. We do not.
Mechanical, electrical, and plumbing engineering firms designing custom building systems. The strongest direct-fit category for the R&D credit in the AEC sector. Wages typically represent 75% of the qualifying spend, with senior engineers anchoring the bulk of qualifying time.
Senior mechanical and electrical engineer time on energy modeling, load calculations, system iteration, and design coordination
Software licensing for energy modeling tools (Trane TRACE 3D Plus, IES VE), CAD/BIM platforms used for design experimentation
Specialized engineering subcontractors (controls integrators, commissioning agents, third-party energy consultants)
Architecture firms developing novel design approaches involving genuine technical uncertainty. Qualifying work is concentrated in performance-driven design (envelope, daylighting, sustainability). Wages typically represent 80% of the qualifying spend.
Project architect and senior designer time on envelope iteration, BIM-based performance simulation, and proprietary detail development
BIM software (Revit, ArchiCAD), daylighting and energy modeling tools (Climate Studio, Sefaira, ClimateStudio plugins), prototype materials
Specialty consultants on envelope, daylighting, energy modeling, and sustainability strategy used during the design phase
Design-build firms, design-assist contractors, and specialty contractors who designed the systems they installed. Includes full design-build firms, HVAC contractors, lighting contractors, mechanical contractors, facade contractors, roofing contractors, and BMS/BAS integrators with design responsibility. Activity-based qualification: the work itself qualifies regardless of company classification.
Senior project engineer and field engineer time on system design, constructability iteration, and performance verification under design responsibility
Engineering and modeling software, mockup materials, instrumentation for performance testing during the design and commissioning phases
Engineering subcontractors brought in for specialized analysis (energy modeling, controls programming, commissioning agents)
Energy consultants, commissioning agents, and performance engineering firms doing technical work under genuine uncertainty. Activity-based qualification, with strong overlap on 179D engagements. Wages typically represent 80% of qualifying spend.
Senior energy modeler, commissioning agent, and PE time on calibrated energy modeling, M&V protocol development, and certification engineering
Modeling software (IES VE, TRACE 3D Plus, Carrier HAP), data loggers and instrumentation for M&V, calibration equipment used in commissioning
Specialty subconsultants on advanced modeling, controls verification, or third-party certification when retained for technical analysis
Qualified Research Expenditures (QRE) are the wages, supplies, and contractor costs tied to qualifying technical work. For most architecture, MEP, and contractor firms, wages dominate the QRE base because the qualifying work happens during senior staff design and engineering time.
Credit applies directly against corporate tax liability. Look-back covers the prior 3 years plus the current open tax year.
Most architecture and MEP firms are organized as LLCs, S-Corps, or partnerships. The 179D deduction flows to owners on K-1 and reduces basis dollar-for-dollar (stock basis for S-Corps, outside basis for partnerships). Owner-level deductibility is limited by IRC §704(d) for partnerships and IRC §1366(d) for S-Corps. C-Corps are unaffected because the deduction stays at the entity level. We model both entity-level and owner-level impact during the engagement.
PWA-compliant projects qualify for the bonus rate, roughly 5x higher than the base rate. Many government projects meet PWA via Davis-Bacon obligations.
Other qualifying project types include tribal government buildings, public transportation facilities, public housing authority buildings, nonprofit private schools, courthouses, fire and police stations, and any building owned by a government or 501(c)(3) entity. Contact us if your project type is not listed.
To qualify for a 179D designer allocation, your firm must meet all five criteria below:
A 179D allocation letter is a written document signed by the owner of a government or tax-exempt building that allocates the available 179D deduction to the designer who created the qualifying energy-efficient systems.
The allocation letter identifies the building, the qualifying systems (HVAC, lighting, envelope), the designer receiving the allocation, and the deduction amount being allocated. It is signed by an authorized representative of the building owner. The letter must be issued before the designer claims the deduction on their return. We assist in drafting and securing the letter as part of the study process.
In our experience, building owners agree to sign once they understand the allocation has no impact on their books and provides no cost to them. Owners that have not previously dealt with 179D often have questions about their own tax position, which we walk through directly.
The Inflation Reduction Act expanded the 179D designer allocation pathway in 2023, adding all 501(c)(3) tax-exempt entities and tribal government buildings to the list of qualifying owners.
Before 2023, designer allocations were limited to government-owned buildings only. Designers with projects from 2023 forward on nonprofit hospitals, private universities, religious buildings, museums, affordable housing, and tribal facilities may now have look-back opportunities they did not realize existed.
If you designed energy-efficient systems for a tax-exempt building between 2023 and the current tax year, those projects may still be eligible for an amended-return allocation.
If you designed any of the following systems for a government or tax-exempt building, you may be eligible for a 179D allocation. The deduction can apply when the design covers one, two, or all three categories.
Custom lighting design and controls integration
Mechanical systems including heating, cooling, ventilation, hot water
Wall, roof, fenestration, and thermal performance systems
For full rate history, building owner pathways, and construction start guidance, see our main 179D service page.
Prevailing Wage and Apprenticeship (PWA) is a labor compliance standard tied to federal wage rates and apprenticeship hour requirements. Projects that meet PWA qualify for the bonus deduction rate, roughly 5x higher than the base rate.
Many government-owned buildings effectively meet PWA through existing federal Davis-Bacon obligations or state-level prevailing wage laws. Federal facilities, state and municipal projects, and projects funded by federal grants often have prevailing wage compliance built into the contract from day one. That means PWA may be satisfied without any additional steps, though the determination is project-specific.
Projects that began construction before January 29, 2023 are exempt from PWA requirements and qualify for the full bonus rate without compliance documentation. For projects after that date, eligibility depends on the specifics of the construction contract and labor records. We work through the determination with you during the feasibility study.
| Project Type | Designer | Sq Ft | Rate | Deduction Range |
|---|---|---|---|---|
| Public School | Engineering Firm | 150,000 | Non-PWA | $88,500 to $178,500 |
| Nonprofit Hospital | MEP Firm | 800,000 | Non-PWA | $472,000 to $952,000 |
| City Library | Architecture Firm | 65,000 | PWA | $193,050 to $386,100 |
| State University | Design-Build Firm | 300,000 | PWA | $891,000 to $1,782,000 |
Projects must meet IRC §179D construction start requirements. Current guidance establishes a June 30, 2026 threshold under the One Big Beautiful Bill Act. For details on construction start determination methods, see our main 179D service page.
Both partners run every engagement directly. The PE certifying your 179D study is the same partner you talked to on the discovery call. The engineer running your R&D technical interview is the same person calculating the credit. No handoff to associates, no junior staff fronting senior conversations.
Every R&D study includes documented technical interviews, contemporaneous records, and a four-part test analysis grounded in the regulatory framework. Every 179D study is delivered with PE certification, energy modeling against ASHRAE 90.1, and Form 7205 supporting documentation. The result is a study that holds its own under scrutiny.
Most AEC firms working with national tax firms claim 179D and R&D as separate engagements with separate teams. We run both in parallel with the same partners on the same engagement. One technical interview, one document collection, one delivery, one supporting documentation package across both incentives.
Yes. Architecture and MEP engineering firms qualify for the R&D tax credit under IRC Section 41 when their engineers and designers perform qualifying technical work involving uncertainty resolved through experimentation. This includes custom HVAC and lighting system design, energy modeling, building envelope thermal analysis, BIM-based performance simulation, and proprietary design standard development. Routine code-compliance documentation and standard schematic design without technical experimentation do not qualify.
Qualifying activities involve technical uncertainty resolved through experimentation. Common examples include custom HVAC system design and load calculation, energy simulation and performance modeling, plumbing and fire protection engineering, electrical distribution and lighting design, building envelope thermal analysis, daylighting and passive solar design, BIM-based performance modeling, proprietary design standard development, and design-build engineering with technical uncertainty. Standard schematic design and code-compliance documentation are excluded. The four sub-sectors above show how the four-part test maps to typical AEC work.
A 179D designer allocation is a federal tax deduction transferred from the owner of a government or tax-exempt building to the designer who created the qualifying energy-efficient systems. The deduction is up to $5.94 per square foot for projects meeting Prevailing Wage and Apprenticeship requirements, or up to $1.19 per square foot for non-PWA projects. The designer receives the deduction even though they do not own the building. The deduction is capped at the cost of the designer's services on the project, with a look-back across the prior 3 years plus the current open tax year. See IRS Form 7205 for the federal filing.
It applies to all levels of government ownership: federal, state, county, city, and local. Public schools, state universities, county courthouses, municipal buildings, fire stations, police stations, public libraries, public hospitals, military and VA facilities, and tribal government buildings all qualify when owned by the relevant government entity.
The Inflation Reduction Act expanded eligibility further in 2023 to include all 501(c)(3) tax-exempt entities, which means nonprofit hospitals, private universities, religious buildings, museums, and affordable housing now qualify too.
The common misconception that 179D only applies to federal buildings is outdated. If the building is owned by any level of government or any 501(c)(3) entity, designer allocations are available to the firm that designed the qualifying energy-efficient systems.
The letter is signed by an authorized representative of the building owner, typically a facilities director, finance officer, or executive depending on the entity. For government projects, this is often a contracting officer or department head. For 501(c)(3) buildings, it is usually a CFO or executive director. The letter must be in hand before you claim the deduction on your return. We handle the request and drafting as part of the engagement. In our experience, owners agree to sign once they understand the allocation has no impact on their books and provides no cost to them.
Yes. R&D credit on the engineering design work involving technical uncertainty. 179D deduction on the energy-efficient systems placed in service. Two separate IRC sections, no conflict between them. This is the most common stacking scenario for architecture and MEP firms working on government and tax-exempt projects.
The credit is calculated as a percentage of qualified research expenditures (QRE) using either the Regular Credit method or the Alternative Simplified Credit (ASC) method. We calculate both and apply the optimal method for your firm. For most architecture and MEP firms, wages dominate the QRE base at 70 to 80 percent of qualifying spend, with smaller contributions from supplies and contractor costs. The federal credit typically ranges from 2.5 to 6.25 percent of QRE. See the estimator above for ranges based on your firm's qualifying spend.
Qualifying buildings are those owned by government entities or tax-exempt 501(c)(3) organizations. This includes public schools, state and federal universities, federal facilities, military and VA buildings, public hospitals, nonprofit hospitals, religious buildings, museums, public libraries, municipal buildings, public housing authority buildings, LIHTC affordable housing, tribal government buildings, and nonprofit private schools. The Inflation Reduction Act expanded the qualifying owner list in 2023 to include all 501(c)(3) entities and tribal governments, opening look-back opportunities for designers on those project types.
Yes. Nearly 40 states offer additional R&D credits that can be claimed alongside the federal credit. State credits typically add 5 to 25 percent on top of the federal benefit. State programs vary in their conformity to federal rules, their carry-forward provisions, and whether they include the same qualifying activities. We handle state credit identification and filing as part of the federal engagement.
R&D and 179D run in parallel as one engagement when both apply. Both incentives share a single technical interview, a single document collection cycle, and one delivery package. The R&D study has 4 steps. The 179D study has 5 steps. Partners run both engagements directly. The PE certifying the 179D study is the same partner you talked to on the discovery call. The engineer running your R&D technical interview is the same engineer calculating the credit. See the side-by-side process above for the full step breakdown.
Yes. Both incentives are activity-based, not size-based. Smaller firms often have stronger qualifying ratios because senior engineers and architects spend more of their time on hands-on technical design work, which is exactly the work that qualifies for R&D. For 179D, the deduction scales with the buildings you design, regardless of firm size. We work with firms of every size.
A 30-minute conversation tells us whether your firm has a viable path on R&D, 179D, or both. No fee for the feasibility assessment. Partner-to-partner from the first call.