Self Build Mortgages > Paying it back

How do you pay back a Self Build Mortgage?

The quick answer about paying back your Self Build loan.

During the build: You’ll usually make interest-only payments on the money you’ve drawn so far. Your monthly payments will increase as you access more of the loan.

After the build: Your mortgage will likely switch to a standard repayment mortgage, which should be at a lower rate. This will either be with the same lender or via a remortgage.

How do payments work during the build?

When you secure a self build mortgage, the lender will release your funds in stages. This is typically 5–7 drawdowns tied to milestones like buying the land, laying foundations, building the shell, first fix, second fix, and completion.

During this build phase, most lenders ask you to pay interest only on the amount you’ve drawn so far. This keeps payments lower at the beginning when you’ve only drawn part of the loan, and means you’re not repaying capital until the house is finished.

For example:

  • If you draw £50,000 in stage one, you’ll only pay interest on that £50,000.

  • When you later draw another £100,000, your monthly payments rise to reflect £150,000 outstanding.

  • At no point are you paying interest on the full facility until it’s actually drawn.

This staged approach helps to balance your cashflow during the build, especially if you’re also covering rent or other living costs while the project is underway.

Self built home that's recently completed in the countryside

What changes at completion?

Once your home is finished, the mortgage moves from “build phase” into “normal” mortgage territory. To trigger this, lenders usually ask for:

  • A Building Control Completion Certificate confirming the property meets regulations.

  • A structural warranty or architect’s certificate (Professional Consultant’s Certificate).

  • Evidence of standard buildings insurance.

  • A final valuation of the property as a completed dwelling.

At this point, your mortgage typically switches to a capital-and-interest repayment basis at a lower rate. This is either with the same lender (product transfer) or through remortgaging to another provider. This is when your repayments begin to look like a standard residential mortgage.

Home half way through renovations

Why work with a specialist broker?

Self build mortgages are very different from standard residential mortgages. Getting the wrong structure can leave you short of funds mid-build or paying more than you need to. That’s why working with a specialist broker is so valuable.

A broker like Mayflower understands the differences between arrears, advance, and cost-based stage payments and can match your project to the right product. We know how lenders assess valuations, what documentation you’ll need, and how to avoid delays in moving from build phase to repayment. Most importantly, we make sure you never run out of money at a critical stage.

Why choose Mayflower Mortgage?

At Mayflower, self building is our speciality. We’ve spent over 15 years helping people turn their dreams into real life plans. We know the challenges inside out and are here to help you have the best experience possible.

✔ A dedicated adviser who’ll support you from first plans to final sign off.

✔ Access to lenders and products you won’t find on the high street.

✔ Faster decisions so you can move forward with confidence.

✔ Our unique Self Build Saver Solution, designed to save you thousands across your build.

  • Winner badge

    Best Self Build Mortgage Advisory Firm

    Design and Build Awards 2025

  • Finalist badge

    Best Specialist Broker

    Finalist at the 2025 Mortgage Strategy Awards

  • Logo of Financial Reporter featuring a blue laurel wreath surrounding the letters 'fr' and the text 'financial | reporter' beneath it.

    Best Specialist Broker

    Finalist at the 2025 Financial Reporter Awards

  • Gold oval badge for the National Custom & Self Build Association (NACSA) indicating support as a Gold Partner for 2024, with website www.nacsba.org.uk.

    NaCSBA Gold member

    National Custom & Self Build Association

  • Grand Designs Live logo with black text and a blue circle containing the word 'LIVE' in white

    Grand Designs

    As seen at Grand Designs Live in London

  • Logo for 'Build It Live' event with the phrases 'Self Build,' 'Home Design,' 'Renovation,' and 'Extension' listed below.

    BuildIt Live

    As seen at BuildIt Live

  • Logo for the Homebuilding & Renovating Show celebrating 30 years from 1994 to 2024, with black, blue, and white text.

    Homebuilding & Renovating Show

    As seen at the Homebuilding & Renovating Show

  • NACFB logo with the tagline "Helping Fund UK Business"

    NACFB Member

    National Association of Commercial Finance Brokers

  • Logo for the Association of Mortgage Intermediaries featuring the acronym 'AMI' in white letters inside blue circles, with the full name written below.

    AMI Member

    Association of Mortgage Intermediaries

  • Logo of the Structural Timber Association with the acronym 'STA', a vertical multicolor line, and the words 'Structural Timber Association Member'.

    STA

    Structural Timber Association Member

Ready to get your Self Build Mortgage?

At Mayflower, we specialise in self build, renovation, and conversion mortgages. We’re here to help you choose the right payment structure, guide you through the build phase, and make sure you switch smoothly to a repayment mortgage when the house is finished.