The Capital Stack Explained: Debt, Mezz, Pref, and Common Equity

The Capital Stack Explained: Debt, Mezz, Pref, and Common Equity

Every real estate deal is financed by a capital stack — the layered set of money that funds the purchase, ordered by priority. The ordering is the entire concept: each layer has a defined place in line for the property's cash flow and, in a bad outcome, for its value; the lower a layer sits, the sooner it gets paid and the later it takes losses, and the return each layer earns is the price of its position. Understand the stack and you understand simultaneously why lenders earn less than sponsors, why "preferred equity" is neither quite debt nor quite equity, and where — exactly, to the dollar — your money starts losing in a downturn.

This explainer walks the stack layer by layer on one worked example, then covers the mezz-versus-pref distinction that confuses everyone, the loss ladder computed, the honest economics of stacking layers at all, and how the whole structure gets modeled. All figures are illustrative examples.

The Diagram and the Two Flows

The stack is conventionally drawn as a column: senior debt at the bottom, then mezzanine debt, then preferred equity, then common equity at the top. Two flows run through it in opposite directions, and the pair is the whole mental model:

• Cash flows bottom-up. The property's income pays the senior lender first, then mezz, then pref, and whatever remains belongs to common.
• Losses flow top-down. A decline in value erases common equity first, then pref, then mezz, and touches the senior lender only after everything above it is gone.

Position determines both, and both determine price: the bottom of the stack trades safety for modest yield, the top trades first-loss exposure for uncapped upside, and every layer between is a negotiated point on that line.

The worked stack — an illustrative $10,000,000 acquisition:

The percentage bands are the layer's attachment and detachment points — the slice of the property's value it occupies — and they are the most useful single fact about any position, because they answer the investor's real question: how far does value have to fall before my dollars are the ones burning?

Layer 1: Senior Debt — the Bottom, and the Boss

The mortgage: first claim on cash flow, first lien on the property, and the last capital impaired. Its safety is engineered by everything covered in the debt underwriting cluster — LTV caps, coverage minimums, debt-yield floors — which collectively hold the senior position to the bottom slice of value where losses essentially never reach it. The price of that safety is the lowest return in the stack and no participation in upside: a 7% loan on a deal that doubles is still a 7% loan.

The senior lender is also the stack's governor: its loan documents typically restrict or condition everything layered above it (more on intercreditor mechanics below), which is why stacks are negotiated from the bottom up.

Layer 2: Mezzanine Debt — a Loan Against the Company

Mezzanine fills the gap above what the senior will lend — in our stack, the 60–75% slice. It is genuinely debt: a loan with a rate, a maturity, and a default remedy. But its collateral is different in a way that defines it: the mezz lender's security is typically a pledge of the equity interests in the entity that owns the property, not a lien on the property itself (the senior loan usually prohibits junior property liens). On default, the mezz lender's remedy is a UCC foreclosure on those ownership interests — becoming, in effect, the new owner of the borrower entity, subject to the senior loan, on a timeline dramatically faster than a mortgage foreclosure.

The senior-mezz relationship is governed by an intercreditor agreement — standstills, cure rights, transfer conditions — and mezz pricing (illustratively 12% here) reflects the 60–75% attachment: real cushion below it, real leverage above the senior's comfort zone.

Layer 3: Preferred Equity — Equity Wearing a Coupon

Preferred equity occupies the next slice up (75–85% here) and the conceptual middle ground that generates most of the confusion. It is equity — an ownership interest in the deal entity, not a loan — but structured to behave like credit: a fixed preferred return (illustratively 13%, sometimes split between current-pay and accrued/PIK), priority over common for both distributions and return of capital, and negotiated remedies if it isn't paid — classically the right to take control of the entity (replacing the sponsor as manager) rather than to foreclose on anything.

The pref-versus-mezz distinction, compressed:

Functionally they can occupy the same slice at similar pricing; structurally they are different animals, and which one a deal uses is frequently decided by the senior lender's requirements as much as by the sponsor's preference. The accrual mechanics of the preferred return itself — simple versus compounding, current versus PIK — are exactly the preferred return machinery from the waterfall world, applied one layer down the stack.

Layer 4: Common Equity — First Loss, Full Upside

The top slice — here $1,500,000, the 85–100% band — is the sponsor's and common investors' money: last in line for every dollar, first erased by any decline, and the owner of everything left after the fixed claims are satisfied. Its return is uncapped and unpromised, which is why common equity underwrites to the highest targets in the stack and why, within the common layer itself, the GP/LP split adds one more distribution structure — the equity waterfall, which is really the capital stack's logic applied recursively inside its top slice.

The Loss Ladder, Computed

Now the stack's core arithmetic — where losses land as value falls (illustrative, straight to the attachment points):

• Value −15% (to $8.5M): common equity wiped, exactly — the 15% common slice absorbing a 15% decline to the dollar. Everyone above is whole.
• −20% ($8.0M): common gone; preferred equity impaired $500,000 of its $1,000,000.
• −30% ($7.0M): common and pref both wiped; the loss reaches $500,000 into the mezzanine.
• −45% ($5.5M): everything above the senior is gone and the senior itself is $500,000 impaired — the scenario its 60% attachment point was engineered to make remote.

Read as an investor: your layer's attachment point is your risk statement. Pref at 75–85% in this stack survives a 15% decline untouched and is destroyed by a 25% one — a sentence more informative than any pitch-deck adjective, and computable in ten seconds from the stack table. Read as a sponsor: every layer added above the senior raises the fixed claims that must be cleared before common sees anything, concentrating the common position's risk in exchange for its smaller check.

The Honest Economics of Stacking

Which raises the question the diagram alone doesn't answer: why build a tall stack at all? The sponsor's answer is leverage on the equity check — $1.5M of common controls a $10M asset. But the worked stack carries a warning worth computing: the blended cost of everything above common is $730,000 a year (8.59% on the $8.5M of senior + mezz + pref), while the property at an illustrative 6.5% going-in cap produces only $650,000 of NOI — a negative $80,000 current spread. Every layer of this stack is being paid, in part, out of the common investors' pocket or the deal's reserves until the income grows into the structure.

That is not automatically wrong — it is the standard shape of a heavy value-add stack, financing a plan whose stabilized NOI is meant to overtake the carry — but it is a bet with a clock, and the stack model's first job is to say so out loud: current-pay coverage by layer, the accruing (PIK) balances compounding where cash runs short, and the growth-and-time path at which common turns positive. A stack whose economics only work in the pro forma's later years has all its risk concentrated in getting there — which is, precisely, the negative-leverage logic from the debt metrics applied to every layer at once.

Modeling the Stack

A capital stack model is a waterfall with more floors, and the construction disciplines transfer directly from the waterfall build patterns: per-layer accounts (balance, accrual, payments), cash allocated strictly by priority each period with MIN-cascade mechanics, PIK accruals compounding into balances where current cash falls short, each layer's remedies and triggers flagged, and — the outputs that matter — per-layer returns, per-layer coverage, and the loss ladder as a live table rather than a one-time memo exhibit. Plus the exit: at sale or refinance, the stack unwinds bottom-up, and the model's final tie-out is that the proceeds allocation honors every attachment point on the way to common.

Reading a Deal's Stack Before You Invest

For the LP or pref investor evaluating an offering, the stack analysis compresses to five questions, all answerable from the deal documents:

1. Where do I attach and detach? Compute your band from the sources-and-uses — it is your loss ladder position, and the worked math above shows it takes ten seconds. Distrust any offering where the full stack isn't disclosed plainly enough to compute it.
2. Is my return current-pay, accrued, or split? A 13% pref paid 7% current / 6% PIK is a different investment than 13% cash — the accrual is a promise whose value depends on the exit, and the compounding mechanics determine what the promise grows into.
3. What happens when I'm not paid? Remedies are the position's real teeth: control-takeover rights with defined triggers versus a polite accrual are different securities at the same coupon.
4. Who can change the stack? Refinancings and recapitalizations reshuffle the column mid-hold — new senior proceeds can pay layers down (good for you) or new layers can be inserted (read your consent rights). The stack at closing is the opening position, not the whole game.
5. How do I exit? Trace your dollars through the unwind: at sale, who is paid before you, and does the waterfall in the documents match the stack diagram in the deck? Mismatches between the marketing exhibit and the operating agreement are found by exactly this exercise, and finding them is the diligence.

The pattern across all five: the stack diagram is the claim; the documents are the security. Read the second.

Frequently Asked Questions

What is the capital stack in real estate? The layered structure of a deal's financing — senior debt, then mezzanine and/or preferred equity, then common equity — ordered by priority: cash flows to the bottom layers first, losses land on the top layers first, and each layer's return prices its position.

What is the difference between mezzanine debt and preferred equity? Legal structure, mostly: mezz is a loan secured by a pledge of the ownership entity (UCC foreclosure as remedy); pref is an equity interest with contractual priority and control-takeover remedies. They can occupy the same slice at similar pricing — which one a deal uses often turns on the senior lender's requirements.

Is preferred equity safer than common equity? It sits below common in loss order — in the worked stack, pref survives a 15% value decline that erases common entirely — at the price of a capped return. "Safer" is a statement about attachment points, and the ladder above shows how to read yours.

Why would a sponsor add mezz or pref instead of raising more common equity? Smaller common checks and (when the layers price below the deal's returns) accretion to the common position. The honest counterweight is the worked stack's negative current spread: fixed claims stack up faster than income in heavy structures, and the model's job is to price the bet's clock.

Can the capital stack change during the hold? Routinely — a refinance replaces the senior layer (and often pays down or retires mezz and pref with the proceeds), a recapitalization can insert new layers, and rescue capital in distressed deals frequently arrives as new preferred equity senior to the existing common and sometimes the existing pref. Your protection against unfavorable reshuffling is whatever consent rights your documents grant — which is why question four in the reading list above belongs in diligence, not discovery.

Where does the GP/LP waterfall fit in the capital stack? Inside the common layer — the stack allocates between the layers; the waterfall then allocates the common layer's share between sponsor and investors. Same priority logic, applied recursively.

Model the Whole Column

The Preferred Equity & Cap-Stack Model implements the full structure: senior debt, mezzanine, preferred equity with both PIK and cash-pay mechanics, and common equity, with distribution by tranche, the preferred-return accounts, and sensitivity on exit cap and leverage — the loss ladder and per-layer returns as live outputs — fully unlocked, formula-transparent, versioned, with a documented methodology PDF. The full model catalog is in the store.

This article is for educational purposes only and does not constitute investment, legal, or tax advice. All figures are illustrative examples. Capital stack terms vary by deal; the loan documents and operating agreements govern — have them reviewed by qualified counsel.