Contingency in Development Finance: How Much Lenders Expect

Most UK development finance lenders expect a contingency of 5% to 10% of build costs, held outside the building contract and released only with the Monitoring Surveyor’s approval. Where you land in that range depends on the type of scheme, how far the design has progressed and how well you can evidence the figure. A contingency with no reasoning behind it is one of the quickest ways to weaken a funding proposal.

This guide covers what lenders look for, how the money is controlled once the facility is live, how to size it for new-build against refurbishment, and how to deal with build cost inflation.

TL;DR

• Expect to hold 5% to 10% of build costs as contingency. Ground-up schemes with fixed-price contracts sit at the lower end; refurbishment, conversion and complex sites sit at the upper end.
• Lenders test the figure against a risk register. A round number with no evidence reads as padding.
• Contingency should sit in the developer’s budget, outside the contractor’s price, or it is effectively already spent.
• Once the loan is live, the lender’s Monitoring Surveyor controls spend against contingency and reports monthly on whether the remaining funds can finish the job.
• Inflation is best handled as its own line with a stated rate and duration, not buried in the general contingency.

Table of Contents

• What contingency is for
• How much do lenders expect?
• Why a bare percentage is not enough
• Where the contingency sits matters
• How contingency is controlled once the loan is live
• Avoid the double-counting trap
• Allowing for inflation
• Contingency by development type
• Presenting contingency to a lender
• Our perspective
• Funding a scheme with the right buffer
• FAQ
• Sources

What contingency is for

Contingency is money set aside for costs you cannot price yet. It is not a fee, a profit buffer or a place to hide an optimistic cost plan. It covers things like unforeseen ground conditions, a utility diversion nobody anticipated, a latent defect uncovered during strip-out, or a design change the planners insist on.

The GOV.UK development appraisal tool manual describes it as the percentage of building costs set aside for unanticipated building events and problems, particularly on schemes with a high level of build cost risk such as refurbishments and large complex projects. That is the definition lenders work from, even if they apply it more strictly.

For a lender, your contingency is the first buffer between a cost overrun and their capital. That is why it is among the first lines they test in an appraisal.

How much do lenders expect?

The commonly quoted range is 5% to 10% of total build costs. Industry commentary has repeated this for years: a Development Finance Today interview with a quantity surveyor reported how many proposals arrive with inadequate contingency or none at all, and that lenders now expect a credible, robust proposal.

In practice the figure moves with risk:

Treat that table as a guide to how lenders tend to think, not a rule. Each lender has its own credit policy, and a high-quality contractor, a thorough site investigation and a full set of surveys can all justify a lower figure. Weak information can push it up.

A worked example

Take a scheme with build costs of £4,000,000 excluding contingency.

• At 5%, contingency is £200,000.
• At 7.5%, it is £300,000.
• At 10%, it is £400,000.

That £200,000 gap between the low and high ends is real cash that must be funded, either from the facility or from your equity. It also affects your loan to cost and your profit on cost. So the difference between 5% and 10% is not cosmetic. It changes how much capital the deal needs on day one.

Why a bare percentage is not enough

The weakest proposals state “10% contingency” and stop. Lenders and their professional advisers want to see why.

RICS guidance on management of risk points professionals toward a structured approach. The NRM1 cost framework groups project risks into four areas: design development risk, construction risk, employer change risk and other employer risks. Larger projects use quantitative risk analysis, including Monte Carlo simulation, to set contingency at a chosen confidence level such as P80, rather than relying on a flat rate.

You do not need a Monte Carlo model for a six-unit scheme. You do need the logic behind one:

1. List the risks specific to this site and build.
2. Put a realistic cost and likelihood against each.
3. Add them up and compare with your percentage.
4. Explain any gap.

Build a simple risk register

A one-page register is enough for most schemes. For each line, record the risk, the owner, the estimated cost if it happens, the likelihood, and the point in the programme at which it retires.

Typical lines might be:

• Ground conditions and abnormal foundations, retiring once groundworks are signed off
• Party wall disputes or neighbour issues
• Utility connections and diversions
• Material price volatility on long-lead items
• Latent defects in existing structures (refurbishment)
• Planning condition discharge delays

A register turns a percentage into a story the lender can follow. It also helps you later, because you can show contingency being released as risks fall away, which demonstrates control.

Where the contingency sits matters

There are two broad places contingency can live. It can be embedded in the contractor’s price, or it can be held by you as a separate line outside the contract sum.

The RICS guidance for lenders’ independent monitoring surveyors says it is important to understand how contingency is structured into total development costs and how its spend is authorised, and notes that it can exist at different levels under different parties’ management.

The practical consequence is this. If contingency is buried in the contractor’s price, it is spent by definition, because the contractor is paid it whether or not the risk occurs. A developer-held contingency outside the contract sum is more useful to both sides. The lender has a genuine buffer, and you keep the flexibility to save the money if the risks do not materialise.

When you present the cost plan, show the contingency as a separate, clearly labelled line in the drawdown schedule, and state the rules for how it is released.

How contingency is controlled once the loan is live

For most development facilities, the lender appoints an independent Monitoring Surveyor (MS) to oversee the build. Their role on contingency is central.

Under the RICS guidance, spend against contingency needs authorisation, and the MS reports on progress and cost to complete. In practice this means:

• You cannot simply draw contingency like any other cost line. You request it, with evidence of what the spend covers and why it was unavoidable.
• The MS gives a regular view, typically monthly, on whether the remaining funds are enough to complete the project.
• If the MS concludes the remaining budget is insufficient, drawdowns can be held until the gap is covered, usually by further equity from you.

That last point is the one that catches developers out. Contingency exhausted early in the programme leaves nothing for the riskier later stages, and the lender may stop funding until you top up. Use it as a reserve for genuine unknowns, not to absorb avoidable cost creep in the first few months.

If an overrun looks likely, tell the lender and the MS early. Surprises at drawdown stage damage trust far more than a flagged problem with a plan attached.

Avoid the double-counting trap

Bigger is not always safer. RICS valuation guidance on development property warns about allowing for the same risk twice. If your appraisal already uses a risk-adjusted discount rate or a generous profit target to reflect uncertainty, piling a large flat contingency on top can make a viable scheme look marginal.

So be deliberate. Decide which risks the contingency covers, which are covered by profit margin, and which are transferred to the contractor under the contract. Write that down. It also helps when a lender asks why your figure is below the top of the range.

The opposite error is more common though. Treating contingency as a way to inflate costs and extract more margin is something lenders spot by benchmarking your figure against similar projects, and it tends to raise questions about the whole appraisal.

Allowing for inflation

Readers often ask whether inflation belongs inside contingency. Our view is that it should be shown separately.

General contingency is for events you cannot predict. Inflation is a forecastable pressure: you can pick a rate and apply it to the unfixed parts of the budget over the programme. Showing it as its own line is more transparent and easier for a lender to test.

Choose the rate carefully. BCIS notes that general indices such as CPI can differ from construction costs: CPI was 3.3% in March 2026, while its General Building Cost Index annual inflation was 3.8% on provisional data. On a £10 million project, the gap between the two is around £50,000 a year of potential underestimate, according to the same article.

A sensible approach:

1. Fix as much of the price as you can with the contractor, so there is less exposed to inflation.
2. For the unfixed packages, apply a construction-specific rate over the months remaining until each is bought.
3. Show the inflation allowance as a separate line from general contingency.
4. Review it at each stage of the build.

If you buy materials early or agree a fixed-price contract with a credible contractor, you can often argue for a smaller allowance, and lenders will usually accept that if the contract terms support it.

Contingency by development type

Ground-up new-build

With full planning, a complete design package and a fixed-price build contract, 5% is often acceptable. Show the contract form, what is excluded, and how provisional sums are handled. Provisional sums are a frequent source of overrun and lenders read them as unpriced risk.

Refurbishment and conversion

Expect the upper part of the range. Existing structure, services and hidden defects are hard to price before strip-out. Surveys and intrusive investigations before you submit will let you argue for a more precise figure.

Heritage, basement and complex schemes

These are priced at the top of the range or above. Specialist advice on structure and ground conditions can narrow the uncertainty, which is the best argument for a lower number.

Phased schemes

The risk profile changes by phase. Early phases carry ground and infrastructure risk; later ones carry finishes and sales risk. A phased contingency release schedule, tied to your risk register, suits these deals.

Presenting contingency to a lender

A lender reading your proposal wants to see five things:

• A contingency percentage appropriate to the scheme type
• A risk register that explains it
• Clear separation from the contractor’s price
• A stated release mechanism as risks retire
• A separate inflation allowance, if relevant

Pair those with sensitivity analysis showing how the scheme performs if costs rise and values fall. If the numbers only work with contingency removed, that tells you the scheme is underfunded, not that the contingency is too high.

If you are also working out how the whole capital structure fits together, our guide on structuring a development finance deal when margins are tight shows how senior debt, mezzanine and equity can be arranged around the cost plan. For a wider view of the lender market, see our overview of development finance lenders in the UK.

Our perspective

We arrange structured property finance for developers and investors, and contingency is where we see proposals strengthen or fall apart. The pattern is consistent: lenders do not penalise a high contingency that is well explained, but they do penalise a low one that is not.

Our advice is to build the contingency before you approach a lender, not in response to their query. Do the risk register first, decide who owns each risk, and set the contingency outside the contract. A clear paper trail lets us go to specialist lenders and private credit funds with a proposal that reads as professionally managed, and that matters most when time is short and the structure is complex.

We also encourage developers to think of contingency as part of the whole debt stack. Where a scheme is tight, the answer is sometimes not shaving contingency but changing the funding mix, for instance adding mezzanine or JV equity so the senior lender sees a robust buffer and a lower loan to cost. That is a structuring conversation, and it is better had early.

— James William Dawes

Funding a scheme with the right buffer

If you are putting together a development appraisal and want to test how much contingency your senior lender is likely to accept, we can help. We arrange development finance, mezzanine and joint venture equity for UK developers and investors, with a single point of contact from structuring through to execution. Send us your cost plan and risk register and we will tell you where the proposal is strong and where a lender will push back.

FAQ

What does contingency mean in development finance?

It is a sum within the project budget set aside for unforeseen costs, such as ground problems, design changes or hidden defects. Lenders require it as a buffer so that a moderate overrun does not leave the project short of funds. It is usually held separately from the contractor’s price.

What does a 10% contingency mean?

It means you add 10% of the build cost as a reserve. On a £2,000,000 build budget that is £200,000 on top. It is common for refurbishment, conversion and complex schemes, and the lender will expect it to be funded and supported by a risk register.

Can I use contingency to increase my profit?

Not legitimately. If contingency is unspent, it is released and normally increases profit at the end, but lenders look unfavourably on padding it to inflate margins. A figure tied to specific risks is credible; one picked to flatter the appraisal is not.

Who controls contingency once the loan is drawn?

The lender, through its Monitoring Surveyor. Spend against contingency needs authorisation, and the surveyor reports on whether the remaining funds are enough to finish. Drawdowns can be paused if they conclude there is a shortfall.

Should inflation be part of contingency?

Preferably not. Show it as a separate allowance with a stated rate and period, using a construction cost measure rather than general CPI. That keeps general contingency for genuine unknowns.

Sources

• RICS: Lender’s independent monitoring surveyor
• RICS: Management of risk
• RICS: Valuation of development property
• GOV.UK: Development appraisal tool user manual
• Development Finance Today: inadequate or no contingency
• BCIS: Construction inflation

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