R&D Tax Credits for Building System Controls 2026

Building automation and control systems (BACS) firms sit at the intersection of engineering, software, and energy efficiency. The work is technical, custom, and often involves solving problems no one has solved before.

Building system controls R&D credits 2026 reward this work. Here is what qualifies and how to document it.

Important note on Section 174A expensing: The enactment of Section 174A under the One Big Beautiful Bill Act of 2025 (P.L. 119-21), signed July 4, 2025, means domestic R&D costs are once again 100% immediately deductible in the year incurred for tax years beginning after December 31, 2024 . Foreign research expenditures must still be capitalized and amortized over 15 years .

2022-2024 catch-up opportunity: Taxpayers with unamortized domestic R&D balances from the TCJA mandatory capitalization period (2022-2024) may elect to deduct those remaining amounts in full on their 2025 return or ratably over 2025 and 2026 . The special window for small taxpayers (average gross receipts of $31 million or less) to retroactively amend prior-year returns for the Section 174 change closed on July 6, 2026 . The 2025/2026 catch-up deduction is now the only remaining statutory option for recovering past capitalized domestic R&D balances .

The Four-Part Test Applied to Building System Controls

To qualify, your activities must meet all four IRS requirements under IRC Section 41.

1. Permitted Purpose

Your work must aim to develop or improve a product, process, or software.

Examples:

• Designing a new building automation platform

• Developing control algorithms for HVAC optimization

• Creating custom system integration solutions

• Improving energy management systems

2. Technological in Nature

The work must rely on engineering, computer science, or physics.

Examples:

• Control system programming and logic design

• Sensor integration and data analytics

• Energy modeling and simulation

• Network architecture for building systems

3. Elimination of Technical Uncertainty

You must face uncertainty about capability, method, or design at the project’s outset.

What creates uncertainty:

• “Will this control sequence achieve the required energy reduction?”

• “Can we integrate legacy systems with new IoT sensors without latency issues?”

• “Will this algorithm maintain comfort while reducing peak demand?”

4. Process of Experimentation

You must show systematic evaluation through testing, prototyping, or trial and error.

Qualifying activities:

• Testing alternative control sequences

• Trialing different sensor placements and configurations

• Running energy simulations to compare design options

• Commissioning and performance validation

Failed experiments count. The IRS rewards experimentation, not just success.

What Qualifies in Building System Controls

Example: A controls firm develops a new BACS platform that uses IoT sensors and machine learning to optimize HVAC and lighting in large-scale warehouses. The project involves designing proprietary hardware and software to integrate with legacy power grids.

What Does Not Qualify

• Routine installation of standard control systems without experimentation

• Routine maintenance or troubleshooting of existing systems

• Standard programming using established methods without technical uncertainty

• General business functions: Sales, marketing, administrative work

• Applying proven solutions without addressing technical uncertainty

Understanding building system controls R&D credits 2026 also means knowing what does not qualify—routine installation, standard configuration, and maintenance without experimentation.

Which Expenses Qualify

Section 174A & Section 280C Coordination

The enactment of Section 174A under the One Big Beautiful Bill Act of 2025 (P.L. 119-21) made domestic R&D costs fully expensible in Year 1. Because of this, controls firms need to coordinate their Section 174A deduction elections with IRC Section 280C to ensure they maximize both immediate cash-flow relief and the Section 41 credit .

Under Section 280C(c), taxpayers claiming an R&D credit must either reduce their Section 174/174A deduction by the amount of the credit claimed or elect the reduced credit under Section 280C(c)(2) to preserve the full expense deduction .

State Programs for Building System Controls

Wisconsin: Enhanced Credit Rate for BACS

Wisconsin offers an enhanced R&D credit rate of 11.5% for research related to the design and manufacturing of energy-efficient lighting systems and building automation and control systems that reduce demand for natural gas or electricity or improve efficiency of use.

This is double the standard Wisconsin research credit rate of 5.75%.

Key details:

• Research must be conducted in Wisconsin

• Must use separate Schedule R for BACS research versus general research

• Documentation must include a Project Narrative addressing the four-part test and how the project reduces energy demand

Note: State caps, application windows, and rates are subject to annual legislative updates. Verify current figures with a qualified tax professional.

Documentation Best Practices

The IRS expects contemporaneous records—not reconstructed studies assembled years later. For controls firms, this means documenting the technical uncertainty and experimentation process from the start.

What to document:

• Project narratives addressing the four-part test

• Technical challenges and uncertainties faced

• Control sequence alternatives tested and why they failed or succeeded

• Time tracking for engineers and programmers

• Prototype build logs and test results

• Evidence of how the project reduces energy demand

• Cloud resource tagging reports linking compute usage to R&D projects

How to document it:

• Use project codes to separate R&D from routine installation and maintenance

• Maintain version control for all control programming and design documentation

• Use resource tagging on cloud platforms to segregate development, experimentation, and production usage

• Store all records in organized, accessible format

• Ensure documentation is contemporaneous (created during the work, not reconstructed later)

Bottom Line

Building system controls R&D credits 2026 are one of the most valuable incentives for an industry that innovates at the intersection of engineering, software, and energy efficiency. Control system design, system integration, energy optimization, and IoT development can all qualify.

The combination of Section 174A domestic expensing and federal R&D credits under Section 41 makes 2026 one of the most advantageous tax years for controls innovation. Wisconsin’s enhanced 11.5% credit rate for BACS adds even more value for companies operating in that state.

Call (844) 463-2400 or email hello@indagotax.com to discuss which activities in your building system controls firm qualify.