Calculator
Capital stack calculator
Layer senior debt, mezzanine and equity on your scheme. The calculator sizes each layer the way funders actually do, shows which cap binds the senior facility, and tells you the cash the stack still needs.
Send us the appraisal and we will return indicative terms for each layer, senior, mezzanine and the equity, within one business day.
How this capital stack calculator works
The calculator builds the stack from the bottom up, the same order a funder reads it. The senior facility is sized against two caps at once: 65 per cent loan to gross development value (LTGDV), the facility as a percentage of the finished scheme's end value, and your chosen loan to cost (LTC) ceiling, the facility as a percentage of hard costs, meaning land, build and contingency. The senior debt is the lower of the two, and the result card tells you which cap binds. On tight-margin schemes LTGDV usually bites first; on schemes with a healthy margin it is normally LTC.
The mezzanine layer then tops the debt up to your combined ceiling, set as a percentage of hard costs, 90 per cent by default. Switch the layer off and the gap simply moves into the equity line. Equity is the residual: total project cost, which is hard costs plus all the finance costs, less the two debt layers. That residual is the cash the scheme needs from you, a JV partner, or both.
Finance costs are estimated honestly rather than precisely. Senior interest rolls into the loan rather than being serviced, and because the facility draws in stages we charge it on an assumed average drawn balance of 55 per cent of the facility over the term. That is a proxy for a typical drawdown profile, not a cashflow model; a scheme that draws heavily early will cost more, one that draws late will cost less. Mezzanine interest is charged on the full balance from drawdown, because mezzanine usually funds the land and is fully out the door on day one. Fees are fixed in this model at 1.5 per cent on the senior facility and 2 per cent on the mezzanine.
Reading the results
Four numbers matter. The stack bar and the layer cards show the size of each slice. The blended debt rate is the weighted average cost across senior and mezzanine, useful for comparing a layered stack against a single stretch facility. The equity required card is the cash the deal still needs after the debt, the number a JV partner would be asked to fund. And profit on cost, projected profit divided by total cost, is the first test every funder applies: as of June 2026 senior lenders want at least 17.5 per cent, and equity partners want 20 per cent plus.
A worked example: the default £2.4m scheme
The defaults model a six-unit scheme: £2,400,000 GDV, £600,000 land, £1,000,000 build and a 10 per cent contingency, so hard costs of £1,700,000 over an 18-month term. The 65 per cent LTGDV cap allows £1,560,000 of senior debt; the 65 per cent LTC cap allows only £1,105,000, so loan to cost binds and the senior facility is £1,105,000 at 8.5 per cent. Mezzanine tops the debt up to 90 per cent of hard costs, £1,530,000, so the mezzanine slice is £425,000 at 14 per cent. Rolled interest and fees across both layers add roughly £192,000, taking total project cost to about £1,892,000, leaving an equity requirement of around £362,000 and profit on cost just under 27 per cent, comfortably above the lines funders test.
The full anatomy of these layers, who provides each one and what each costs, is on our capital stack page. If the mezzanine slice is the part you are weighing up, our mezzanine finance page covers how second-charge lenders price and what their intercreditor terms involve.
Outputs are illustrative estimates based on the stated assumptions, not a quote, an offer of finance or advice. Actual facility sizes, rates and fees depend on the scheme, the sponsor and the funder's underwriting at the time.
Frequently asked questions
What is a capital stack in property development?
The capital stack is the full set of funding layers that pay for a development, ordered by repayment priority. Senior debt sits at the bottom and is repaid first, mezzanine debt sits above it as a second charge, and equity sits at the top, repaid last from whatever profit remains. Each layer prices according to its position in that queue: senior development finance at 7 to 11 per cent per annum as of June 2026, mezzanine at 14 to 20 per cent, and equity through a profit share rather than a coupon. Our capital stack page explains each layer in detail.
How does this capital stack calculator size the senior debt?
The calculator applies two caps at once and takes the lower. The first is 65 per cent loan to gross development value (LTGDV), the facility as a percentage of the finished scheme's end value, which is fixed in this model. The second is your chosen loan to cost (LTC) ceiling as a percentage of hard costs, meaning land, build and contingency. On the default scheme the LTC cap of £1,105,000 is lower than the LTGDV cap of £1,560,000, so loan to cost binds, and the result card tells you which cap is binding on your numbers.
How is rolled interest estimated in this calculator?
Development facilities draw down in stages as the build progresses, so you do not pay interest on the full senior facility from day one. The calculator approximates this by charging senior interest on an assumed average drawn balance of 55 per cent of the facility across the term, a reasonable proxy for a typical staged drawdown profile but an assumption, not a quote. Mezzanine interest is charged on the full balance from drawdown, because mezzanine usually funds early costs such as the land and is fully drawn from the start. Fees are fixed at 1.5 per cent on the senior facility and 2 per cent on the mezzanine.
How much equity do I need in a development capital stack?
In this model, equity is the residual: total project cost, meaning hard costs plus rolled interest and fees, less the senior and mezzanine debt. With debt running to 90 per cent of hard costs, the equity slice on the default £2.4m GDV scheme is roughly £362,000, around 19 per cent of total cost. That slice is funded by your own cash, a JV partner, or a mix, and reducing the combined debt ceiling increases it pound for pound.
What profit on cost do lenders want to see on a layered stack?
Profit on cost is the projected profit divided by total project cost, and it is the first number a credit committee checks. As of June 2026 senior lenders generally want at least 17.5 per cent, and mezzanine lenders and equity partners want more, typically 20 per cent plus, because their money sits further up the stack and the margin is their only downside protection. The calculator flags whether your scheme clears the 17.5 per cent line.