Compare 10 commercial cost segregation firms for 2027: engineering-led specialists, national tax firms and boutiques, with study volumes and property types.
Commercial cost segregation is where the largest dollar benefits sit. An office building, hotel, warehouse or shopping center carries far more short-life components than a house: dedicated electrical and plumbing for equipment, specialty finishes, parking lots, site lighting and landscaping. A well-supported study can move a meaningful share of a 39 year building into 5, 7 and 15 year classes.
This guide to cost segregation for commercial property is for owners, developers, fund managers and the CPAs who serve them. We focused on firms that run an engineering-based commercial cost segregation study, publish their track record on their own site, and cover a broad range of commercial property types. We favored firms that disclose study volumes, years in business and the makeup of their teams. For a broader view of the market, see our main roundup of the best cost segregation companies.
The rules that matter for 2027: the One Big Beautiful Bill Act, signed July 4, 2025, permanently restored 100% bonus depreciation for qualifying property acquired after January 19, 2025 (property under a binding contract signed before January 20, 2025 stays on the older phase-down). It also created a new 100% deduction for qualified production property: owner-occupied manufacturing and production buildings where construction begins between January 20, 2025 and December 31, 2029 and the property is placed in service before 2031. Confirm eligibility with your CPA.
Commercial Cost Segregation At A Glance
Company
Headquarters
Best For
Standout
KBKG
Offices in Los Angeles, New York, Atlanta, Chicago, Dallas, Detroit and Houston
Owners with varied commercial portfolios
Specialty tax firm since 1999 with CCSP-credentialed principals
Engineered Tax Services
West Palm Beach, Florida
Owners who also want 179D, 45L or R&D work
Licensed engineering firm with eight US offices
CSSI
Baton Rouge, Louisiana
High-volume commercial owners
More than 65,000 studies since 2003
CSA Partners
Not published (nationwide)
Commercial real estate specialists
30,000-plus studies and a fee refund guarantee
McGuire Sponsel
Not published (national)
CPA firms referring commercial clients
Works with more than 450 CPA firms in all 50 states
Source Advisors
Arlington, Texas
Businesses bundling fixed asset and tax incentive work
More than 40 years in specialty tax
Capstan Tax Strategies
Dresher, Pennsylvania
Hotels, restaurants, retail and self-storage
Engineers, tax attorneys and analysts on one team
ELB Consulting
New Port Richey, Florida
Properties above $500,000
More than 14,000 studies since 2002
Duffy+Duffy
Offices in Columbus, Westlake (Ohio) and Novi (Michigan)
New construction and LEED projects
CPAs paired with construction engineers and estimators
R.E. Cost Seg
Not published (serves all 50 states)
Smaller commercial owners who want a virtual inspection
KBKG was established in 1999 and has offices in Los Angeles, New York, Atlanta, Chicago, Dallas, Detroit and Houston. Its cost segregation practice is led by principals who hold the CCSP credential, and its published case studies span 27 building types, including apartments, hotels, hospitals, cold storage, warehouses, self-storage, supermarkets, restaurants and R&D facilities.
A KBKG study can include a physical inspection and interviews, and the firm can estimate component values on site when construction records are missing, which matters for older acquisitions. Beyond cost segregation, KBKG handles R&D credits, 179D, 45L, repair versus capitalization reviews, partial disposition and fixed asset depreciation reviews. It is not owned by a CPA firm, so it works alongside your existing accountant.
Best for: Owners and CPA firms with a mixed commercial portfolio who want one independent specialist for depreciation and related incentives.
Engineered Tax Services describes itself as a licensed engineering firm specializing in tax strategy. It is headquartered in West Palm Beach, Florida, with offices in Dallas, Charlotte, Las Vegas, Los Angeles, New York, Phoenix and Raleigh, and its team includes engineers, CPAs and tax attorneys. The firm cites more than 25 years of experience.
For commercial owners, the appeal is breadth. ETS runs cost segregation alongside 179D deductions, 45L credits, R&D credits, 1031 exchange services and grants, so a developer can review several incentives on one project. It prefers site visits but also runs remote studies for smaller or less complex buildings using photos, video walkthroughs and digital documents.
Best for: Developers and owner-operators who want cost segregation coordinated with energy and R&D incentives.
3. CSSI — More Than 65,000 Studies Completed Since 2003
CSSI is a Baton Rouge, Louisiana firm that has focused on engineering-based cost segregation since 2003 and reports more than 65,000 completed studies. Its work is centered on commercial property, though it also accepts multifamily and vacation rental engagements.
The firm works through the client’s existing CPA, who implements the study on the return, which suits owners who want to keep their current advisor. CSSI also offers 179D and R&D credit services. Its scale means it has seen most building types more than once, from office and hotel to self-storage, which helps when an asset has unusual components.
Best for: Commercial owners and CPA firms that want a high-volume specialist with a long track record.
4. CSA Partners — Commercial Real Estate Specialists With 30,000-Plus Studies
CSA Partners has worked in cost segregation and energy incentives since 2006, when it was started by a father-son team with construction backgrounds. It positions itself as a commercial real estate specialist, reports more than 30,000 engineering-based studies, and works nationwide with CPAs, developers and investors.
Its leadership includes a CPA as chief financial officer and a dedicated chief technology officer. The firm offers a guarantee: if a significant depreciation item is disallowed after an audit, it refunds its engagement fee. That is a concrete commitment worth comparing against the audit terms of other providers.
Best for: Commercial owners who want a focused specialist and a written fee guarantee.
5. McGuire Sponsel — Fixed Asset Specialist Working With 450-Plus CPA Firms
McGuire Sponsel is a national specialty tax firm built around fixed assets, R&D credits, global business services and location advisory. Its fixed asset practice covers cost segregation, qualified production property and 179D, and it says it works with more than 450 CPA firms across all 50 states.
The firm lists industries including hotels and resorts, multifamily, manufacturing, auto dealerships, assisted living, restaurants and life sciences. Its attention to qualified production property is useful in 2027, since the 2025 law created a new full deduction for owner-occupied production buildings. Manufacturers weighing a new facility can look at cost segregation and that election together.
Best for: Manufacturers and CPA firms that want cost segregation tied to qualified production property and incentive planning.
6. Source Advisors — Specialty Tax Firm With More Than 40 Years In Practice
Source Advisors is a specialty tax firm based in Arlington, Texas, that says it has been working for more than 40 years. Its real estate services cover commercial property and portfolios, alongside fixed asset consulting, property tax, sales and use tax, LIFO inventory, energy incentives and Section 174 work.
That range makes it a fit for operating businesses that own their buildings and want cost segregation handled by the same firm that reviews their other incentives. Its team includes CPAs, attorneys, engineers and technology specialists, and it also operates in the UK.
Best for: Owner-occupiers and multi-state businesses that want cost segregation bundled with wider tax incentive work.
Capstan Tax Strategies, based in Dresher, Pennsylvania, runs cost segregation with a multi-disciplinary team of engineers, tax attorneys and analysts. It lists hotels, restaurants, retail properties, self-storage and real estate generally among its cost segregation sectors, and names manufacturing, multifamily and dealerships as asset-rich verticals.
The firm also handles R&D credits, 179D, investment and clean electricity credits, EV charging credits, predominant use studies and unit of property analysis. It serves clients nationwide and runs Capstan University training, which can help CPA firms build internal knowledge of these incentives.
Best for: Owners of hospitality, retail and self-storage property who want an engineer and tax attorney team.
8. ELB Consulting — In-House Engineers And 14,000-Plus Studies Since 2002
ELB Consulting has specialized in cost segregation since 2002 and reports more than 14,000 completed studies in all 50 states. It is based in New Port Richey, Florida, and its studies are performed by in-house engineers.
ELB targets owners and investors with properties above $500,000 and lists apartments, auto dealerships, hotels and resorts, medical centers, manufacturing, golf courses, office complexes, REITs, mixed-use, shopping centers, convenience stores and car washes. For smaller projects that do not need asset-level detail, it refers owners to a separate DIY tool, which is a sign it is candid about when a full study is not needed.
Best for: Mid-size commercial owners who want an engineering-led boutique with a long record.
9. Duffy+Duffy — CPAs And Construction Engineers For New Builds And LEED Projects
Duffy+Duffy pairs CPAs with construction engineers and estimators, and has offices in Columbus and Westlake, Ohio, and Novi, Michigan. It works with builders, developers, investors, franchisees and CPAs, on any commercial building purchased or constructed since 1987.
The firm highlights work on high-efficiency and LEED-certified construction projects, where specialty systems can be hard to classify without detailed plans. It begins with preliminary project information to estimate the benefit, then quotes a flat fee for the study, and client accounts describe reviews of construction plans and on-site visits.
Best for: Developers and franchisees with new construction, especially energy-efficient or LEED buildings in the Midwest.
10. R.E. Cost Seg — Engineered Commercial Studies From $2,730 With A Virtual Inspection
R.E. Cost Seg publishes commercial pricing, which is uncommon in this market. Its fully engineered commercial study starts at $2,730, with the final fee set by square footage, property type and complexity. The study includes a 30 to 60 minute virtual inspection by video call, and in-person visits are available for an added fee.
The firm reports more than 20,000 completed studies and lists warehouses, self-storage, hotels and motels, apartment complexes, restaurants, shopping centers, nursing homes, gas stations, office buildings and industrial manufacturing. Deliverables include a fixed asset ledger with photos, and written audit support is included. Form 3115 is a $600 add-on.
Best for: Owners of smaller commercial buildings who want an engineered study at a published price.
How To Choose A Commercial Cost Segregation Firm
Is The Study Engineering-Based?
The IRS Cost Segregation Audit Techniques Guide favors detailed, engineering-based approaches. Ask who will inspect the building, who prepares the cost estimates and how each component is documented. Our explainer on how cost segregation works covers the methods.
Has The Firm Studied Your Property Type?
A hotel, medical office or manufacturing plant has very different components from a strip center. Ask for sample reports or case studies on similar buildings. For hospitality assets, see our list of cost segregation firms for hotels.
What Happens If The IRS Asks Questions?
Compare audit terms in writing. Some firms provide written defense of their methodology, some refund fees if items are disallowed, and few provide direct representation.
Can They Cover Related Incentives?
New construction may also qualify for qualified production property treatment or energy incentives. A firm that reviews these together can save a second engagement. Confirm current rules for 179D and 45L, which the 2025 law cut back, before relying on them.
How Is The Fee Set?
Most commercial firms quote a flat fee after a free benefit estimate. Get the fee, the deliverables and the timeline in writing, and ask your CPA to review the estimate before you sign.
Frequently Asked Questions
How Much Does A Commercial Cost Segregation Study Cost?
Fees depend on the size and complexity of the building. A few firms publish starting prices around $2,700 to $3,000 for smaller commercial property, while large or specialized buildings are quoted individually.
Can I Do A Study On A Building I Bought Years Ago?
Often yes. A look-back study can catch up missed depreciation through Form 3115 and a 481(a) adjustment, without amending prior returns. Your CPA should confirm eligibility.
Is A Site Visit Required?
Not always, but it is considered best practice for larger and more complex commercial buildings. Some firms accept video walkthroughs and detailed documents for simpler properties.
Conclusion
The firms above range from large national specialists with tens of thousands of studies to engineering boutiques that know specific building types well. Choose based on your property type, the depth of engineering support, audit terms and whether you need related incentives reviewed too. If your portfolio is mostly residential, compare our list of cost segregation firms for multifamily investors.
This article is general information, not tax or legal advice.
