- Home
- For CPAs
Offer cost segregation to your clients
Bring us in as the engineering specialist on your clients' commercial and 5+ unit multifamily properties. 425+ CPAs, advisors and real estate groups already work with Seneca.
You handle the return. We handle the engineering.
A cost segregation study is an engineering exercise with a tax outcome. Bring us in for the engineering half, and for the Form 3115 preparation that goes with it.
- The engineering specialist. Commercial estimates are prepared by Engineering, and every study is signed off by our Head of Engineering.
- Form 3115, prepared for you. The narrative, the form, the calculations and the supporting schedules.
- Directly with you, throughout. We work with the CPA from the estimate to the final deliverable.
- Large look-back portfolios. Deep experience delivering Form 3115 for large look-back study portfolios.
- A partner on audit defense. Lifetime audit defense is included with every study.

CPAs, advisors and real estate groups work with Seneca.
Who does what on a look-back
The accounting method change is your filing. Everything that goes into it is our work, and we stay with you while it is prepared.
Your firm
- Files Form 3115 with the return
- Signs it
- Adds the taxpayer information
Seneca
- The narrative
- The form
- The calculations
- The supporting schedules
Client situations worth a conversation
They bought a commercial building this year
The allocation is being made now, on this return. An engineered study puts the components in the right lives from the start.
They have owned one for years with no study
A look-back study claims the missed depreciation through Form 3115, which we prepare for you to sign and file. No amended returns.
They finished a renovation or build-out
Short-life components, qualified improvement property, and a partial asset disposition on what was removed.
They are building a production facility
Qualified production property under §168(n) can reach the production portion of the building itself.
They are underwriting an acquisition
A pre-acquisition estimate puts the depreciation into the underwriting before closing.
They are planning a sale or exchange
Exit planning covers recapture and 1031 coordination, worked through with you.
Partner firm questions
Still have a question? Ask Engineering.
Who files and signs Form 3115?
Your firm does. The client's CPA files and signs it and adds the taxpayer information. We prepare everything else: the narrative, the form, the calculations and the supporting schedules.
Do you work with us directly?
Yes. We work directly with the CPA throughout, from the estimate to the final deliverable.
Can you handle a large look-back portfolio?
Yes. We have deep experience delivering Form 3115 for large look-back study portfolios.
How quickly can we get a proposal for a client property?
Engineering prepares the estimate, and you receive a written, fixed-fee proposal within 24 to 48 hours.
What does audit defense cover?
Lifetime audit defense for the taxpayer and the property while under their ownership, included with every study: responding to IRS information requests about the study at the agent and appeals level, answering for workpapers, photos and methodology questions, and correcting the report if the IRS finds an error on our side.
Which client properties belong on this site?
All commercial property and multifamily with 5 or more units. Clients with 1 to 4 unit properties or short-term rentals are served through senecacostseg.com.
Talk to us about a client property
Fixed-fee proposal in 24 to 48 hours.
- Prepared by Engineering
- Lifetime audit defense
- NDAs available
Request your estimate
Estimates are prepared by our Engineering team.
Request received
Engineering will review the property and send your written estimate and proposal within 24 to 48 hours.
Preview site: this form is not yet connected, so nothing was sent.