Do enough due diligence before making an offer to know the property is plausibly worth your number — and no more. Pre-offer diligence is desk research: ACRIS records, zoning, violations, taxes, and rough underwriting, done in days at near-zero cost. Deep diligence — inspections, environmental assessments, legal review — belongs after your offer is accepted, inside the contract period, when you have a deal to justify the spend. Buyers who invert this sequence lose twice: too much pre-offer work means you move slowly and lose deals to faster bidders; too little means you sign contracts on properties you should have screened out for free. In NYC, where Skyline Properties has brokered $976M+ in transactions, the fast-but-informed offer wins.
The two-phase framework: screen cheap, verify deep
Due diligence is not one activity — it is two phases with different costs, tools, and purposes. Phase one, pre-offer, answers a single question: is this property plausibly worth my number? It uses public records and rough math, costs almost nothing, and should take days. Phase two, post-acceptance, answers a different question: is everything I assumed actually true? It uses engineers, environmental consultants, attorneys, and title companies, costs five figures or more, and runs during the contractual diligence period your attorney negotiates. The offer — typically expressed as an LOI in NYC commercial deals — is the gate between the phases, and it is protected by contingencies precisely so that committing to a price does not mean committing blind.
Calibrating how much time the whole arc should take is its own question — see how much time due diligence takes on NYC commercial properties for phase-by-phase timelines.
Pre-offer desk research, step by step
Here is the pre-offer sequence Skyline runs on every candidate property — all of it from a desk, most of it from free public records, in two to four days.
- Pull the ACRIS file — retrieve the deed, current mortgages, and transaction history from NYC's public recording system to confirm who actually owns the property, what they paid, and what debt sits on it.
- Confirm the zoning envelope — check the zoning district, permitted uses, and FAR on ZoLa to verify the property can legally do what your thesis assumes, including any unused development rights.
- Search open violations — run DOB, HPD, FDNY, and ECB violation searches; open violations transfer with the property and convert directly into price adjustments or walk-away signals.
- Pull the tax bill and assessment history — the Department of Finance file shows current taxes, the assessment trajectory, and any abatements or exemptions that expire on sale.
- Build a rough underwriting model — apply market rents, realistic expenses, and a submarket cap rate to test whether the asking price is within range; Skyline's cap rate calculator and NOI calculator handle the arithmetic in minutes.
- Stress-test the seller's story — compare the claimed rent roll and expenses against public benchmarks and comparable trades; gaps between story and record are where offers get mispriced (see how to verify off-market property information).
- Decide and move — if the screen holds, issue the offer with appropriate contingencies within days; speed at this stage is itself a competitive weapon in NYC.
Pair this sequence with the right seller-facing questions — our companion piece on questions to ask before buying commercial real estate covers what to ask the human beings while the records answer the rest.
What NOT to do before offering
Do not commission engineering reports, Phase I environmental assessments, appraisals, or full legal review before you have an accepted offer. Each costs thousands to tens of thousands of dollars, takes weeks, and buys you certainty about a property you do not control — if another buyer offers while you perfect your knowledge, you have purchased a very expensive education about someone else's building. In competitive NYC situations, the buyer who offers in week one with a clean LOI routinely beats the buyer still refining a model in week three.
The exception that proves the rule: if a single issue is genuinely thesis-critical and cheap to resolve — a zoning question your architect can answer in a phone call, a violation search — resolve it. The discipline is spending in proportion to deal probability, not eliminating uncertainty before commitment. Uncertainty is what contingencies are for.
After acceptance: where the real diligence lives
Once your offer is accepted and counsel is negotiating the contract, the deep work begins: physical inspection by a licensed engineer (structure, facade, mechanicals, roof), Phase I environmental assessment and Phase II testing if flagged, title and survey review, lease audits and estoppel certificates on tenanted buildings, service-contract review, and insurance-loss history. On a mid-size NYC commercial deal this package runs roughly $15K–$75K+ and three to six weeks — which is exactly why it happens after acceptance, funded by a live deal rather than a hope. The commercial due diligence guide details every workstream.
Findings feed back into the deal in one of three ways: a price adjustment (credits for discovered capex), a contractual cure (seller resolves violations before closing), or termination under a contingency. This is the machinery that makes fast pre-offer commitment safe — you committed at a price subject to verification, and verification is now doing its job. Findings that should genuinely kill deals are covered in our red flags guide.
Calibrating by deal type and competition
The two-phase split flexes with context. In a competitive marketed process, compress pre-offer work to the essentials and lean harder on contract protections. In a negotiated off-market deal — where Skyline does most of its work — there is usually more room to ask questions before offering, because no other bidder is racing you; use it, but don't abuse it, since off-market sellers grant access expecting momentum. On vacant land, pre-offer zoning work grows and building inspection disappears; on a fully leased office building, lease-file review dominates the contract period. Skyline's off-market sales — including the $135M sale of 6 East 43rd Street and the $105M sale of 101 Greenwich Street — closed with sophisticated buyers who committed quickly on desk-level conviction and verified deeply in contract.
How Skyline approaches buyer diligence
Skyline Properties front-loads the desk research for its buyers: ACRIS history, debt position, violation file, tax trajectory, and a defensible underwriting range arrive with the opportunity, because off-market investment sales only work when qualified buyers can commit quickly and confidently. Robert Khodadadian, Founder, President & CEO, has run this sequence across $976M+ in closed transactions — the deals close because the pre-offer screen was honest and the contract diligence confirmed it.
Serious buyers can join the buyer network to receive vetted off-market opportunities, or submit an acquisition mandate so we run the screen against your specific buy-box.
Frequently asked questions
- How long should due diligence take before making an offer?
- Two to four days for a competent pre-offer screen on most NYC commercial properties: ACRIS ownership and debt records, zoning check, violation searches, tax history, and a rough underwriting model — all desk work from public records at near-zero cost. Deep diligence (engineering, environmental, legal) belongs in the contract period after your offer is accepted, and typically runs three to six weeks. Buyers who try to complete both phases before offering routinely lose deals to faster, equally protected bidders.
- Can I make an offer on commercial property without any due diligence?
- You can, but you shouldn't — and you don't need to choose between speed and safety. A two-to-four-day public-records screen (ownership, debt, zoning, violations, taxes, rough underwriting) catches most mispriced deals for free, and the contingencies in your contract protect everything the screen can't see. The failure modes are symmetrical: offering blind wastes contract-period costs on properties a free search would have killed; over-researching loses the deal to a faster bidder.
- What does contract-period due diligence cost on a NYC commercial deal?
- Roughly $15K–$75K+ on a mid-size transaction, depending on building complexity: engineering and facade inspection, Phase I environmental (a few thousand dollars; Phase II testing more if flagged), title and survey, legal review, and lease audits on tenanted buildings. That real money is exactly why the spend belongs after an accepted offer, inside a negotiated diligence period — you are verifying a deal you control, not researching one you might never win.
- Is due diligence different for off-market deals?
- The workstreams are identical; the rhythm differs. Off-market sellers grant access without the pressure of competing bidders, so buyers usually get more pre-offer question time — but they extend that access expecting momentum, and buyers who stall lose the relationship. Verification also matters more because there is no marketed offering memorandum: you confirm the rent roll, expenses, and physical story against public records yourself, which is why disciplined off-market buyers lean hardest on the desk-research screen.