Commercial Real Estate Financial Model: Office, Retail, Industrial

Commercial Real Estate Financial Model: Office, Retail, Industrial

A multifamily model and a commercial model compute the same outputs — NOI, coverage, IRR — from structurally different worlds. Multifamily revenue is a statistic: dozens or hundreds of similar leases, individually trivial, whose behavior averages into smooth assumptions (a vacancy percentage, a rent-growth rate). Commercial revenue is a contract schedule: a handful of large, long, idiosyncratic leases, none of which averages with anything, each of which is a named risk with a date attached. Everything distinctive about commercial modeling — the lease-by-lease build, the recovery machinery, the rollover event, TI/LC — follows from that one structural fact.

This pillar covers the commercial model end to end: the lease-driven revenue engine, the expense-recovery layer, the rollover event as the model's central mechanic (with a fully computed example of what one expiry actually costs), the credit and vacancy treatments, the exit logic, and where the simpler and deeper modeling tools each belong. All figures are illustrative examples, not market data.

The Revenue Engine: One Row Per Lease

The commercial model's foundation is the lease schedule — one row per tenancy, projecting each lease's contractual income through the hold:

• Tenant, suite, rentable square feet
• Rent per SF and the escalation terms that grow it (fixed annual steps, periodic bumps, CPI-linked)
• Lease structure — NNN, gross, or modified, determining the recovery treatment below
• Term: commencement, expiration, and any options (renewal, termination, expansion) with their dates and terms
• Concessions and abatements in effect

The projection multiplies out mechanically until each lease's expiration — at which point the model's real work begins (the rollover section below). Two disciplines govern the build: it starts from the actual leases via a lender-grade rent roll (the rent roll format guide covers exactly what that document must carry, and the commercial variant's structure column is why), and it never smooths — a model that converts three tenants into "95% occupancy at $15 blended" has thrown away precisely the information commercial underwriting exists to price.

The Recovery Layer: What "Rent" Means

Commercial rent numbers are meaningless without their structure, because the structures allocate operating expenses differently: under NNN, tenants reimburse taxes, insurance, and CAM on top of base rent; under gross, the landlord absorbs them; modified structures and expense stops (the tenant pays increases over a base year) sit between. The model therefore carries a recovery engine: each expense line allocated to tenants per their leases' terms, producing reimbursement income beside base rent — and producing the landlord's true expense exposure, which under NNN is concentrated in the vacant space (vacancy costs a commercial landlord twice: the rent and the unreimbursed expenses on the empty suite). The structures, their economics, and the base-rent-equivalence math between them are the subject of the NNN vs. gross lease guide; the model-level requirement is that the recovery terms are per-lease inputs, not a building-wide toggle.

The Rollover Event: the Model's Core Mechanic

Every lease expiration in the hold period triggers the commercial model's defining calculation. At each expiry, the model asks four questions, each an input:

1. Does the tenant renew? — a renewal probability, informed by the tenant's situation, the suite's marketability, and the market
2. If not, how long is the suite dark? — downtime months to re-lease
3. At what rent does the next lease sign? — the market reset, up or down from the expiring contract
4. What does the new revenue cost? — tenant improvements (the buildout allowance, quoted per SF, dramatically higher for a new tenant than a renewal) and leasing commissions (a percentage of the new lease's value)

The computed example. A 12,000 SF flex tenant paying $14 NNN ($168,000/year) expires in year three. Illustrative rollover assumptions: 65% renewal probability; if the tenant leaves — nine months of downtime, $25/SF of TI, and a 6% commission on a five-year lease; if it renews — $8/SF of TI and a 2% commission.

• New-tenant path: $126,000 of downtime rent loss + $300,000 TI + $50,400 LC = $476,400
• Renewal path: $96,000 TI + $16,800 LC = $112,800
• Probability-weighted expected cost: about $240,000 — roughly 1.4 years of the tenant's entire rent.

That one number is commercial real estate's economics in miniature. A single scheduled expiry carries an expected cost on the order of a year and a half of the space's income — which is why commercial cash flows are lumpy by construction (the model's capital line spikes in rollover years), why the renewal-versus-new gap makes tenant retention a four-hundred-thousand-dollar activity rather than a soft skill, and why every input in the rollover block deserves market evidence rather than defaults. It is also why the model must carry the event per lease, on its date — an "average annual TI/LC reserve" smooths away the year-four capital cliff that the financing plan needed to see.

TI/LC: the Capital Cost of Revenue

The rollover math surfaces commercial modeling's least intuitive truth: commercial revenue has a capital cost. TI and LC sit below NOI (they are capital items, not operating expenses — the NOI boundary rules hold), but they are as certain as the expiration dates that trigger them, and a model that computes NOI-based metrics while ignoring the TI/LC line beneath is quoting a yield the property cannot distribute. The honest presentation carries both: NOI for valuation and coverage conventions, and cash flow after TI/LC and capital reserves for what the owner actually receives — with the gap between them, in rollover-heavy years, being most of the story.

Vacancy and Credit: Specific, Then Statistical

Two more consequences of the few-large-leases structure:

Vacancy is an event, not a rate. The model's primary vacancy is the specific downtime in the rollover engine — suite by suite, dated. A modest general vacancy overlay on top (a small percentage haircut) covers the unmodeled friction, but a commercial model whose only vacancy is a blanket percentage has imported multifamily's statistics into a world where they don't apply.

Credit is a name, not a category. When one tenant is 40% of revenue, that tenant's financial health is an underwriting input: credit tenants versus local businesses justify different renewal probabilities, different downside scenarios (the model should be able to answer "what if Tenant A leaves at expiry — or before it?" as a scenario, not a shrug), and different exit pricing. Concentration metrics belong on the dashboard: largest tenant's share of revenue, and WALT — the rent-weighted average lease term remaining — the single number commercial buyers and lenders read first, because it is the duration of the income they are buying.

The Exit: Buyers Price the Rent Roll

The reversion logic follows the same structural fact. A commercial exit value is not just forward NOI at a market cap — it is forward NOI as shaped by the rent roll the buyer inherits: a year-ten sale with the anchor lease expiring in year eleven trades very differently than the same NOI with eight years of WALT, because the buyer is pricing their own imminent rollover event (they can compute the $240,000 too). The model should therefore report the rent roll at exit — WALT, near-term expiries, in-place versus market rents — beside the reversion, and the exit-cap assumption should be reasoned against it. Engineering the hold period so the sale precedes the expiry cliff, or leases are renewed into it, is one of commercial asset management's genuinely modelable decisions.

Asset-Class Notes: How Office, Retail, and Industrial Flavor the Machine

The machinery above is common to all commercial property; the asset classes set its dials differently.

Office is the TI-intensive case: buildouts are expensive, re-leasing downtimes run long, and the rollover engine's cost side dominates — which is why office models live and die on their rollover assumptions, and why the expected-cost arithmetic above understates the stakes for a full-floor office expiry. Parking income and amenity costs add lines; the recovery engine typically runs expense-stop or modified-gross structures.

Retail adds revenue machinery of its own: percentage rent (a share of tenant sales above a breakpoint — a lease row that needs a sales assumption), co-tenancy clauses (rent relief or termination rights triggered if an anchor leaves — a contractual chain reaction the model should carry as a scenario), and anchor/inline dynamics where the anchor's below-market rent is the price of the inline tenants' above-market ones. Retail credit analysis is really sales analysis: occupancy-cost ratios (rent as a share of tenant sales) are the early warning the rent roll alone can't show.

Industrial runs the machinery at its gentlest settings — low TI, longer terms, modest downtime in healthy markets — which shifts the underwriting weight onto what remains: tenant credit (frequently single-tenant, where the lease is the asset), functional attributes that drive re-leasability (clear height, loading, power), and the mark-to-market on long leases signed in a different rent environment. A single-tenant industrial model is closer to credit analysis with a reversion than to a diversified rent roll.

Same model, three calibrations — and the calibration choices are themselves underwriting statements that a credit committee will read.

The Debt Side Reads the Rent Roll Too

Commercial lenders underwrite the same lease schedule, and the model should anticipate how. Loan terms get structured around the rollover profile: TI/LC reserves (upfront or ongoing deposits earmarked for re-leasing costs), cash-flow sweeps triggered as major expiries approach or if a key tenant goes dark, and loan maturities deliberately set against the WALT — a lender is reluctant to mature into the same year as the anchor lease, for the same reason a buyer discounts it. For the model, this means the debt block on a commercial deal is not fully specified by rate, amortization, and proceeds: the reserve and sweep mechanics are cash-flow items with dates, and a pro forma that ignores them overstates distributable cash in exactly the years the rollover engine already flagged as expensive. The coverage machinery is standard; the structuring around the lease schedule is the commercial addition.

Multifamily vs. Commercial: the Summary Table

	Multifamily	Commercial
Revenue	Statistical (unit mix × market rents)	Contractual (lease-by-lease schedule)
Vacancy	A percentage assumption	Specific downtime events + small overlay
Expenses	Landlord bears	Allocated by lease structure (recoveries)
Re-leasing cost	Turnover make-ready	TI/LC — a capital line with dates
Key risk metric	Economic vacancy, expense ratios	WALT, expiry concentration, tenant credit
Cash flow shape	Smooth	Lumpy by construction

The two models share the downstream machinery — debt sizing, the DCF, returns, sensitivity — which is why the general pro forma template standards apply to both. The revenue half is where they are different species.

The Commercial-Specific Mistakes

1. Blended revenue — averaging the leases away, and the risk with them.
2. Rent numbers without structures — $14 NNN treated as $14 gross, or recoveries omitted entirely.
3. TI/LC missing or smoothed — the capital cliff hidden in an annual reserve.
4. Renewal optimism without evidence — the rollover engine's probabilities defaulted rather than argued.
5. Statistical vacancy only — no dated downtime anywhere in the model.
6. An exit blind to the rent roll — terminal value computed as if the buyer won't read the lease schedule.
7. No tenant-departure scenario — the concentration risk everyone can name, priced nowhere.

Frequently Asked Questions

What is a commercial real estate financial model? A lease-driven underwriting model: per-lease revenue projection with escalations and recoveries, rollover events with downtime and TI/LC at each expiration, tenant-level credit treatment, and the standard debt/DCF/returns machinery on top — for office, retail, industrial, and flex assets.

How is commercial modeling different from multifamily? Structurally: commercial revenue is a few large contracts rather than many small statistical ones, so vacancy becomes specific events, expenses become allocations, re-leasing becomes a capital line, and risk becomes named tenants and dates. The table above summarizes the translation.

What are TI and LC? Tenant improvements (the buildout allowance funding a tenant's space) and leasing commissions (broker compensation on the new lease) — the capital costs of commercial revenue, incurred at each new lease and, more modestly, at renewals. They sit below NOI and above the owner's actual cash flow.

What is WALT and why does it matter? Weighted average lease term — the rent-weighted years of contractual income remaining. It is the duration of the thing a commercial buyer is buying, which is why it headlines every offering memorandum and belongs on every model dashboard.

What renewal probability should I use? One you can defend from the tenant's situation and the submarket — not a universal constant. The computed example shows why it matters: on that lease, each 10 points of renewal probability moves the expected rollover cost by about $36,000.

Two Tools for Two Depths

The lease-by-lease machinery scales with the deal's stakes, and the catalog is built accordingly. The Commercial Sheet is the full acquisition model — the 10-year DCF with the tenant rent roll, lease expiry schedule, vacancy and credit loss treatment, recoveries, DSCR and debt sizing, and the 5×5 sensitivity grid — the working tool for underwriting office, retail, and industrial deals. For the assignments where the rent roll is the analysis — heavy rollover concentration, complex recovery structures, suite-level repositioning — the Commercial Lease-by-Lease Underwriting Model extends the same conventions into deeper per-lease machinery. Both fully unlocked, formula-transparent, versioned, with documented methodology PDFs.

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This article is for educational purposes only and does not constitute investment, legal, or tax advice. All figures are illustrative examples, not market data or cost estimates. Consult qualified professionals before making investment decisions.