Mezzanine finance explained

Mezzanine finance is junior debt that sits between the senior loan and the developer's equity in the capital stack. It tops up the senior facility so the borrower puts in less cash, and in exchange the mezzanine lender accepts a riskier position and charges a materially higher rate. In UK property development it is the most common way to stretch total funding from around 60 to 65 percent of cost up to 85 or even 90 percent.

This guide explains what mezzanine finance is, where it sits, how a mezzanine loan is structured and priced, the security and intercreditor mechanics behind it, the risks, and how it compares with bridging and preferred equity. We use self storage development as the running example because that is the sector we arrange finance in, but the principles apply to any UK development or investment deal. We are a broker, not a lender, and nothing here is investment advice.

What is mezzanine finance?

Mezzanine finance is a second layer of debt that ranks behind the senior lender but ahead of the equity. The name comes from the mezzanine floor of a building: a level inserted between two others. In funding terms it occupies exactly that position, slotted between the cheap, secure senior loan at the bottom of the capital stack and the expensive, exposed equity at the top.

Because the mezzanine lender only gets repaid after the senior lender has been made whole, mezzanine debt carries more risk than senior debt and is priced accordingly. It is still debt, though: there is a loan agreement, a fixed or rolled-up interest rate, a repayment date and security. Some corporate mezzanine structures include warrants or options that convert into shares if the borrower defaults, which is why mezzanine capital is often described as a hybrid of debt and equity. In UK property development the conversion feature is rare; most property mezzanine is a straightforward second-ranking loan, sometimes with a small profit share bolted on.

The practical purpose is leverage. A developer with three viable schemes and enough cash for one can use mezzanine finance to spread that cash across all three, accepting a higher blended cost of capital in exchange for doing more deals.

Where does mezzanine sit in the capital stack?

The capital stack is the order in which the money funding a deal gets paid back. At the bottom sits senior debt, typically a development loan or commercial mortgage secured by a first legal charge. It is repaid first, carries the least risk and therefore the lowest rate. At the top sits the equity, the developer's own cash, which is repaid last, absorbs the first loss and takes whatever profit remains. Mezzanine sits in the middle.

On a typical UK development the senior lender funds around 60 to 65 percent of total cost. The mezzanine lender then advances a further 15 to 25 percent of cost, taking total debt to around 80 to 90 percent, and the developer funds the remainder as equity. Repayment runs strictly up the stack: when the scheme is sold or refinanced, the senior loan and its interest clear first, then the mezzanine loan and its rolled-up interest, and only then does the equity come back with any profit.

That ranking is the whole economics of mezzanine. If the scheme outperforms, the mezzanine lender still only earns its agreed rate while the equity takes the upside. If the scheme underperforms, the equity is wiped out before the mezzanine lender loses a pound, and the mezzanine is wiped out before the senior lender does. Risk and reward both scale with height in the stack.

How does a mezzanine loan work in property development?

A worked self storage example shows the mechanics. Suppose a developer is building a 40,000 sq ft purpose-built store with total costs of £6 million, a figure consistent with UK build costs of £550 to £850 per sq m on PSL Limited's February 2026 construction cost data once land, fees and fit-out are added. A senior development lender offers 65 percent of cost, £3.9 million. Without mezzanine the developer must find £2.1 million in cash.

A mezzanine lender then advances a further £1.2 million, taking total debt to £5.1 million, 85 percent of cost. The developer's equity requirement falls to £900,000. The senior loan might price in the high single digits with interest rolled up; the mezzanine loan might price at 12 to 18 percent annualised, also rolled up, with fees on top. The blended cost of the whole stack rises, but the cash the developer must commit falls by more than half.

During the build both loans draw down against certified construction costs, with the equity usually going in first, then the mezzanine, then the senior facility, so the cheapest money is the last in and the first out. At practical completion the store starts trading, occupancy builds over three to five years, and the developer repays both loans by refinancing onto an investment facility against the trading valuation or by selling. The mezzanine lender underwrites that exit as hard as the senior lender does, because rolled-up interest means nothing is repaid until the end.

What does mezzanine finance cost?

Mezzanine pricing reflects its position in the stack. In the current UK market, property mezzanine typically prices between about 12 and 20 percent a year, against senior development money in the high single digits to low teens depending on leverage and asset. The exact rate depends on how high the mezzanine pushes total leverage, the strength of the scheme, the sector and the borrower's track record. Stretching from 65 to 75 percent of cost is cheaper than stretching from 75 to 90 percent, because the last slice of debt is the most exposed.

Interest is almost always rolled up rather than serviced, since a development produces no income until it completes, and for an operational asset like self storage often little surplus income until occupancy matures. Expect an arrangement fee of around 1 to 2 percent, often an exit fee of similar size, and in some structures a small share of scheme profit instead of part of the coupon. Legal costs are higher than on a senior-only deal because the intercreditor agreement adds a third set of lawyers.

The right way to judge the cost is on blended return on equity, not the headline rate. Paying 15 percent on a £1.2 million slice while releasing £1.2 million of equity into a second profitable scheme is frequently better business than leaving that equity locked in one deal. We model the blended stack both ways before recommending mezzanine to a client, because sometimes the honest answer is that a higher-leverage senior loan or a cheaper stretch facility beats it.

What security does a mezzanine lender take?

A property mezzanine lender typically takes a second legal charge over the site, ranking behind the senior lender's first charge, plus a debenture over the borrowing company and usually a charge over the shares in that company. The share charge matters: if the deal fails, the mezzanine lender can step in and take control of the company that owns the scheme, complete it and protect its position, rather than waiting behind the senior lender in a receivership.

Personal guarantees are common, often capped at a percentage of the mezzanine loan, and on development deals the mezzanine lender will expect the same cost overrun and completion support the senior lender requires. Some senior lenders refuse second charges altogether; in those structures the mezzanine sits as a loan into a holding company above the borrower, secured only on shares, which is riskier for the mezzanine lender and priced accordingly.

The document that makes all of this work is the intercreditor agreement, the contract between the senior and mezzanine lenders that ranks their claims. It governs who gets paid what and when, what happens on default, whether the mezzanine lender can cure a senior default to protect its position, and how long the mezzanine lender must stand still before enforcing its own security. Senior lenders vary widely in what intercreditor terms they will accept, and pairing a senior lender with a mezzanine lender that they will actually sign terms with is a large part of what we do when we arrange a stacked facility.

What are the risks of mezzanine finance?

For the borrower, the main risk is leverage itself. At 85 to 90 percent of cost there is very little margin for error: a build cost overrun, a slow planning discharge, a valuation that comes in light or a slower lease-up can consume the entire equity cushion and leave the developer working for the lenders. Rolled-up interest compounds the problem, because every month of delay adds cost at the mezzanine rate, not the senior rate.

Refinance risk sits underneath that. Most property mezzanine is repaid by a sale or a refinance, and for an operational asset like self storage the refinance depends on trading performance, not just bricks and mortar. A store that reaches month 36 below its business plan occupancy may not support enough senior debt to clear the mezzanine, forcing an extension at penal rates or an equity injection.

For the mezzanine lender the risk is structural: it stands first in line for losses among the lenders, behind only the equity, and its security is subordinated by the intercreditor agreement. That is precisely why the coupon is high. Borrowers should also weigh execution risk, since running two credit processes and a three-way legal negotiation takes longer than a single senior loan. Starting the mezzanine conversation early, alongside the senior process rather than after it, removes most of that friction.

How does mezzanine compare with bridging loans and preferred equity?

Mezzanine and bridging are both short-term, interest-rolled property lending, and they are often confused, but they solve different problems. A bridging loan is usually the senior debt: a first-charge facility used to buy or hold an asset quickly before a sale or refinance. Mezzanine is never the whole loan; it is the junior slice that sits behind a senior facility to increase total leverage. A self storage operator buying a site at auction needs a bridging loan; a developer who already has a senior development facility but wants to halve the cash going into the build needs mezzanine.

Preferred equity is the next layer up the stack from mezzanine. It is an equity investment, not a loan: the preferred investor takes shares or a partnership interest with a priority return, typically has no charge over the property and no intercreditor agreement, and relies on contractual rights in the shareholders' agreement instead of security. Senior lenders that refuse second charges often accept preferred equity precisely because it is not debt. The cost is usually higher than mezzanine, somewhere between mezzanine pricing and a full profit share.

The practical hierarchy for a developer is straightforward. Maximise sensibly priced senior debt first. If more leverage is needed and the senior lender will tolerate junior debt, mezzanine is normally the cheapest route. If the senior lender will not, or the gap is really risk capital rather than debt, preferred equity or a joint venture fills it. We arrange all three layers and the answer is set deal by deal, not by preference for any one product.

Who uses mezzanine finance, and when does it make sense?

The classic mezzanine user is an experienced developer or operator whose ambitions have outgrown their balance sheet. In self storage that profile is common: the sector rewards multi-site scale, new stores absorb cash for three to five years while occupancy builds, and operators who want to keep opening stores during that period need their equity to stretch further. Mezzanine on the second and third developments, funded partly by the maturing first store, is how many UK storage businesses have grown.

Mezzanine makes sense when the scheme's projected profit comfortably exceeds the extra cost of the junior debt, when the developer has a genuinely better use for the equity it releases, and when the exit is credible under conservative assumptions. It makes much less sense as a way to rescue a deal that does not work at sensible leverage, to outbid the market for a site, or to substitute for equity the borrower simply does not have. Mezzanine lenders read appraisals carefully and price desperation quickly.

Lender expectations are higher up the stack, not lower. A mezzanine lender funding a self storage development will want the same feasibility evidence as the senior lender, a demonstrable track record or an experienced operating partner, real cash equity in the deal, and a clear exit. Brought in early, with the senior terms and the intercreditor position mapped before credit committee, mezzanine is a clean and well-understood product. We arrange senior and mezzanine together for exactly that reason.