What is the capital stack, and why does seniority matter?
The capital stack is simply a map of every euro or franc invested in a property and the legal claim attached to it. No real asset of institutional scale is financed by a single source of money. A development or acquisition is funded by layers — a bank loan, perhaps a second lender, an equity sponsor, and co-investors — and each layer signs up to a different position in line.
That position is called seniority, and it works in both directions. When cash flows in (rent, refinancing proceeds, a sale), it pays the most senior claim first and works downward. When cash flows are short or value is destroyed, the loss is absorbed in the opposite order — the most junior capital is wiped out first, and the most senior is touched last. This single ordering principle, often called the 'waterfall,' is the spine of the entire stack.
Seniority matters because it, not the headline return, is what actually defines an investment's risk. Two investors can back the identical building and have completely different risk profiles purely because one sits in senior debt and the other in common equity. Reading the stack is therefore the first analytical step any qualified investor takes — before yield, before location, before sponsor track record.
What are the four layers, from senior debt to common equity?
Senior debt sits at the base of the stack and carries the lowest risk and the lowest return. It is typically a mortgage from a bank, secured by a first-ranking charge over the property itself. If the deal fails, the senior lender can enforce against the asset before anyone else recovers a single unit of capital. In exchange for that security and first position, senior debt accepts the most modest, contractually fixed coupon.
Mezzanine debt sits above senior debt. It is still debt — it carries a fixed or floating interest rate and a defined maturity — but it is subordinated, meaning it is repaid only after the senior lender is satisfied. Its security is usually weaker (often a pledge over the project company's shares rather than a direct first charge over the building). To compensate for ranking behind senior debt, mezzanine commands a higher interest rate.
Preferred equity sits above the debt layers and is the first equity position. It is not a loan, but it carries a 'preferred' right: a defined return (a preferred coupon or hurdle) that must be paid to it before any profit flows to common equity. It usually has limited control rights and a capped or prioritised return rather than unlimited upside.
Common equity sits at the very top — last to be repaid, first to absorb loss. This is the sponsor and the co-investing equity. It receives nothing until every layer beneath it has been served, but it also captures all the residual upside once those obligations are met. It is the highest-risk, highest-return, and most control-rich position in the stack.
How does risk and return move through the stack?
There is one organising rule that explains the entire structure: return is the price paid for accepting a worse position in the queue. Every step down the stack — from senior debt to mezzanine to preferred to common — adds risk, and each layer demands a higher expected return to take it on. This is why a single asset can simultaneously offer a conservative, fixed-income-like profile at the senior-debt level and an equity-like, variable profile at the common level.
The two directions are mirror images. On the way up (distributions), cash is paid out top-down in seniority: senior interest, then mezzanine interest, then the preferred coupon, then whatever remains to common. On the way down (losses), value is destroyed bottom-up: common equity is consumed first as a cushion, then preferred, then mezzanine, and only a catastrophic impairment reaches senior debt. The junior layers literally exist to protect the senior ones — common equity is the shock absorber that lets a bank lend against the asset at a low rate in the first place.
For a qualified investor, this means the relevant question is never simply 'what does this deal return?' It is 'what return am I being offered for the specific position I would hold, and is that return adequate compensation for the risk of that exact slice?' A capital stack makes that question answerable, because it states precisely where each investor stands.
Who typically holds each position?
Different layers attract different kinds of capital, and recognising the pattern helps an investor understand a deal's structure at a glance.
Senior debt is the domain of banks and senior credit funds — capital that wants security and predictability and is content with a modest, contracted return. Their underwriting focuses on the value of the asset and the borrower's ability to service the loan.
Mezzanine debt is provided by specialist debt funds, private credit managers and some family offices seeking yield above what senior lending offers, while staying ahead of all equity. It is a position for investors who want fixed-income characteristics with a higher coupon and can accept weaker security.
Preferred equity is often held by institutional co-investors and family offices that want priority over common equity and a defined return, without taking on full operational risk or wanting day-to-day control.
Common equity is held by the sponsor or developer (whose own capital and 'skin in the game' aligns them with co-investors) alongside equity co-investors who are explicitly buying the upside and accepting they sit last in line. This is the position most associated with value-add and opportunistic real estate strategies.
These are conventions, not rules — a single investor can hold across multiple layers, and structures vary by deal and jurisdiction. But the pattern is consistent enough that the stack itself signals who is in a transaction and what each party is optimising for.
Why does the capital stack matter for institutional execution?
A capital stack is only useful if every participant can see and trust it. In practice this is where many private real estate transactions break down. The stack is described differently in a developer's pitch deck, a bank's term sheet, a lawyer's draft agreement and a dozen email threads — and the version a co-investor signs is not always reconciled against the version the senior lender holds. Seniority, security and the distribution waterfall are precisely the terms that must be unambiguous, yet they are the ones most often scattered across incompatible documents.
For capital that is governed — family offices, institutional investors, regulated balance sheets — that fragmentation is not a cosmetic problem. The position in the stack defines the legal claim, and an ambiguous claim is an unpriceable risk. A professional investor needs the structure stated once, presented consistently to every party, and recorded so that what was agreed cannot quietly drift.
This is the discipline an execution platform is built to enforce: structuring the deal once, presenting the same capital stack to every counterparty in a controlled dealroom, and sealing each step — indication, reservation, signature, settlement — so the agreed structure stays intact from presentation through to reporting. The concept of the stack is finance; making sure it survives contact with the real transaction is execution.