Mortgage guide

Over budget build costs

Read how mezzanine finance may be considered alongside a senior loan when development costs rise, including how Loan to Cost (LTC) affects the funding structure.

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Over budget build costs

We understand that even the best-planned developments can face unexpected cost overruns. When a project runs over budget and your primary lender is unwilling to extend further funds, mezzanine finance can be an effective and strategic solution. Rather than refinancing the entire facility, mezzanine funding allows you to access additional capital to bridge the gap and keep your project on track. One of the key advantages of mezzanine financing is the ability to increase your total borrowing capacity without disrupting your existing loan structure. With Loan to Gross Development Value (LTGDV) available up to 80%, mezzanine loans can raise the total available finance to as much as 80% of your project’s completed market value. This is ideal for developers who have already made significant progress and now need extra funding to cross the finish line.

In many cases, we can also structure mezzanine finance up to 95% Loan to Cost (LTC). This means that between the senior loan and the mezzanine facility, up to 95% of your total development costs can be funded, a crucial safety net for developers who have encountered rising material costs, labour delays, or unforeseen structural works.

Specialist mezzanine finance providers who understand the urgency and complexity of over-budget construction finance. Our panel of lenders is prepared to work alongside your existing senior lender, taking a second charge position without requiring you to refinance the entire project. If you’re facing budget pressures and your current lender has capped their exposure, mezzanine development finance offers a flexible, non-disruptive route to completion. With access to exclusive, broker-only products and a deep understanding of the funding landscape, Mortgage Lane is here to help you secure the support you need and avoid costly project delays.

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Indicative estimate only, based on the figures you enter and the ceilings shown. Lenders also assess experience, planning, the build contract and the exit. This is not an offer of finance. Your property may be repossessed if you do not keep up repayments on a loan secured on it.

Mezzanine financing criteria

For context, these are the wider product terms covered by this guide. Availability and eligibility depend on your circumstances and the lender.

Mezzanine financing criteria
CriteriaDetail
BorrowersPersonal, Ltd co, LLP, Trusts, Offshore Trusts
TermMax 24 months
Max Applicants6
Loan to Gross Development Value (LTGDV)Max 75%
Loan to Cost (LTC)Up to 95%

About the author

Joseph Lane CeMAP is an expert development finance broker

Founder, CEO

Calls and emails here go to Joseph personally, not to a general inbox.

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+44 7487 829005joe@mortgagelane.comMore about Joseph

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Frequently asked questions

Why do self-builds run over budget?

Self-builds commonly run over budget because of ground conditions, design changes, material and labour cost rises, and delays. A costed contingency and staged funding reduce the risk of needing extra finance.

Why do barn conversions go over budget?

Barn conversions often exceed budget because of structural repairs, bringing services to remote sites, access works, insulation and drainage. A substantial contingency protects the exit. Set the contingency using the survey findings and costed work schedule.

What happens if my renovation costs exceed the budget?

You will need to cover the additional cost yourself. Most lenders will only fund the amount agreed at the outset against the original schedule of works.

What happens if my build budget changes?

Inform your lender and provide updated cost estimates. Some lenders will adjust the loan amount against a revised budget, but the change has to be agreed rather than assumed.

How much does bridging finance cost?

Bridging finance typically costs more than a mortgage and is priced monthly, not annually. Expect interest of around 0.6% to 1.5% per month, plus arrangement fees (often 1-2%), valuation fees, and legal costs. Total cost depends on loan length, risk, and structure.

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