Your Home Finance
Self-build lending funds a schedule, not just a house.
Whether stage payments arrive before or after each phase — and whether there's a contingency behind them — decides self-build outcomes far more than the rate on the facility.
30+ years
build finance advice
Cashflow
mapped stage by stage
Contingency
built in
Specialist panel
access
Situation grid
What stage is your build at?
How your case is assessed
How self-build lenders assess a project
A self-build mortgage releases money in stages against a build that doesn't exist yet. Lenders are underwriting the project as much as the borrower — and the mechanics of the release are where the risk sits.
Advance or arrears stage payments
Arrears lenders release funds after each stage is complete and inspected, so you must bridge every phase from your own cash. Advance lenders release at the start of each stage, which is far kinder on cashflow and usually worth paying for.
Plot value, planning and the build cost
Lending is assessed against both the land value and the projected value on completion — typically up to around 75–85% of costs, with a lower percentage of the land. Detailed planning permission, and any conditions attached, materially affect what's available.
Contingency and cost overrun
Lenders expect a contingency, commonly 10–15% of the build cost, and experienced builders plan for more. Overruns are the normal condition of a build, not the exception, and a facility with no headroom is where projects stall.
Build method, warranty and exit
Traditional masonry is the easiest to fund; timber frame, SIPs and other systems narrow the panel. A structural warranty and appropriate site insurance are usually conditions, and the facility needs a planned exit onto a standard mortgage at completion.
You can't plan a build from a rate table — we map the stage payments and the contingency against your actual costs before any hard search.
Specialist insight
Not every self-build project funds the same way
Arrears payments · non-standard build system · no contingency · outline planning only
Higher challenge
Every stage funded from your own cash first · shorter panel for the build method · a single overrun can halt the site until further funds are found.
Advance stage payments · detailed planning · realistic contingency
A build that keeps moving
Funds available before each phase begins · contractors paid on time · a clear exit onto a standard mortgage once the warranty is issued.
Independent reviews
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Your adviser
Jay Sabine
Expert mortgage adviser specialising in complex cases including adverse credit, self-employed borrowers, and first-time buyers. All advice is tailored to your individual circumstances.
Content reviewed: 3 August 2026
CeMAP awarded by The London Institute of Banking & Finance. Cert CII (MP) awarded by the Chartered Insurance Institute.
Specialist in self-build and custom-build mortgage lending
Helping clients with complex credit histories for over 30 years · CeMAP, Cert CII (MP) · FCA regulated
“Self-build cases rarely fail on the mortgage. They fail on cashflow — a stage payment arriving after the invoice, and no contingency behind it.”
Reviewed by Jay Sabine · Mortgage adviser · 30+ years' experience
Lived experience
Mistakes we repeatedly see
Not theory — the patterns that keep stalling otherwise sound builds.
Taking an arrears facility without the cash to bridge stages
Arrears lending sounds cheaper until you realise you must complete and pay for each phase before the money arrives. Without substantial working capital, the build stops between stages while the borrowing costs continue.
Budgeting the build with no contingency
Ground conditions, planning conditions, material prices and specification changes all move. A budget with no headroom means the first surprise becomes a funding crisis rather than an inconvenience.
Buying the plot before the funding is arranged
Land bought on cash or short-term borrowing without a confirmed build facility leaves people holding an expensive field. Plot value and build cost need assessing together, before either is committed.
Forgetting the exit onto a standard mortgage
A self-build facility is temporary. If the finished property, the warranty or your income won't satisfy a term lender at completion, the expensive build rate stays in place far longer than planned.
Real client scenarios
Real self-build journeys
Based on genuine cases we've helped with. Personal details have been changed to protect privacy.
Switched to advance payments — build never stopped
- Arrears offer held
- Cashflow gap found
- Advance lender
- Completed on programme
Situation
A couple with detailed planning on a plot they already owned, holding an offer from an arrears stage-payment lender.
Challenge
The arrears structure required them to fund each stage before release. Their available cash covered the first phase only, and the groundworks alone would have exhausted it.
What changed
We modelled the cashflow phase by phase, demonstrated the shortfall from stage two onwards, and moved the case to an advance stage-payment lender with a 12% contingency built into the facility.
Outcome
The build ran to programme with contractors paid on schedule, and refinanced onto a standard mortgage once the warranty was issued.
Why it worked
The rate on the arrears facility was lower. It was also unusable — and that only shows up when the cashflow is drawn out properly.
Overrun absorbed without halting the site
- Ground conditions
- £40k overrun
- Contingency drawn
- Completed
Situation
A self-builder part-way through a timber-frame house when ground investigations required significantly deeper foundations than designed.
Challenge
The additional cost fell outside the original build estimate, and without headroom the site would have stopped while further funding was sought at the worst possible moment.
What changed
The facility had been arranged with a contingency and a lender comfortable with timber frame, so the additional stage cost was drawn against the existing agreement rather than renegotiated.
Outcome
Foundations completed, programme delayed by weeks rather than months, and the project finished within the funded envelope.
Why it worked
The contingency was argued for at the outset when it felt unnecessary. That's the only point at which it can be arranged cheaply.
What happens after you get in touch
From first contact to a clear answer
What happens when you get in touch — no hard search at this stage.
- 1
We understand the plot, the planning position, the build cost, your build method and the funds you hold (no hard search)
- 2
Jay maps the cashflow stage by stage — including whether payments arrive in advance or in arrears
- 3
We agree a contingency and check the plot and build type against lender appetite
- 4
If proceeding: land purchase → build stages drawn down against inspections → completion onto a standard mortgage
Reassurance
- Free initial review — before any hard credit search
- We model advance and arrears stage payments before recommending either
- If your build budget has no contingency, we'll tell you before you buy the plot
Before you enquire
What we'll ask you on the first call
Straightforward questions — no hard credit search at this stage.
- Whether you own the plot, and the planning position — outline, detailed, or conditions outstanding
- The build cost estimate, who prepared it, and the construction method
- Cash you hold and can commit, and whether you could fund a stage before reimbursement
- Your income position, and what you'll do with your current home during the build
Advisory promise
When we might tell you to wait
We won't always tell you to proceed today.
We may advise waiting where planning is only outline and conditions could change the cost, where the build budget carries no contingency, or where the cashflow shows a gap between stages that no facility on the market would bridge for you.
A stalled build is far more expensive than a delayed start. If the funding sequence doesn't hold up under a realistic cost plan, we'll say so before you commit to the plot. We give advice — not just applications.
Straight answers
Common questions about self-build mortgages
Our promise
What we'll never do
- Tell you to apply if it won't work
- Send applications everywhere
- Recommend borrowing beyond your budget
- Hide bad news
We don't fund a plan. We fund a build — which means the cashflow has to work at every stage, not just on paper at the start.
Plan your self-build funding properly
Tell us about the plot, the planning position and the build cost — we'll map the funding stage by stage.
We don't arrange self-build finance until the stage payment structure, the contingency and the exit onto a standard mortgage have all been worked through.
The land is the easy part. Getting the funding sequence right before you commit is what keeps a build moving to the end.
£500 adviser fee — payable on completion.
Get Clear, Honest Mortgage Advice — Before You Apply
Free consultation • No credit search • FCA regulated
Struggled to get approved elsewhere? We specialise in complex cases including CCJs, self-employed income, and declined applications. Over 90% of our clients had concerns about their situation before speaking to us.
The Basics
Your Needs
Property
Income
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Step 1 of 5
Related guides
Self build — related decisions
If your decision hinges on one of these questions, these chapters go deeper.
Land mortgages
Funding the plot itself, and how lenders value land with and without consent.
Open guide →
Development finance
Where the project is multiple units or commercial rather than your own home.
Open guide →
Non-standard construction
How timber frame, SIPs and other systems affect the lender panel.
Open guide →
Bridging loans
Short-term funding where a plot or a gap needs covering before the facility starts.
Open guide →