Help to Build: 20% to 40% Self Build Loan Explained

What Help to Build is

Help to Build is an English Government equity loan scheme launched in 2022 to help people fund self build and custom build homes. It works like the original Help to Buy scheme but is targeted specifically at people building (or commissioning the build of) their own home rather than buying a developer-built property.

The scheme provides an equity loan of 5% to 20% (or up to 40% in London) of the project cost, repayable when the property is later sold or after a fixed term. The remaining cost is funded by the buyer's deposit and a mortgage from a participating lender.

How the loan works

The loan covers up to 20% of the total project cost (land plus build), or up to 40% in Greater London. The maximum loan amount is £600,000.

For a £400,000 self build project (land plus build) outside London:

• Self build loan: up to £80,000 (20%)
• Buyer deposit: minimum 5% = £20,000
• Buyer mortgage: covers the remainder = £300,000

In Greater London at 40%:

• Self build loan: up to £160,000 (40%)
• Buyer deposit: 5% = £20,000
• Buyer mortgage: £220,000

The loan is interest-free for the first 5 years. After year 5, interest is charged at 1.75% per year, increasing each year by inflation (RPI plus 2%) until the loan is repaid.

Eligibility

You can apply if:

1. You are buying or own a plot of land in England

2. You are commissioning the construction of a new home on that plot

3. You will live in the property as your main home

4. You can secure a self build mortgage from a participating lender

5. The total project cost is within the maximum loan thresholds

The scheme is open to first time buyers and existing homeowners alike. There is no income cap.

What "self build" and "custom build" mean

• Self build: you commission the construction yourself, manage the build (or hire a project manager), and choose the design within planning permission
• Custom build: a developer offers serviced plots with a choice of standard designs, you choose your specification, the developer or contractor builds it

Both qualify for Help to Build provided the project meets the scheme criteria.

How the build is funded

Self build mortgages typically release funds in stages tied to construction milestones (foundation, shell, watertight, first fix, completion). The Help to Build loan is also released at construction milestones, in coordination with the mortgage lender.

The buyer must have at least 5% of the total project cost as a cash deposit, paid into the project before any drawdown.

Repaying the loan

You repay the Help to Build loan when:

• You sell the property (the loan is repaid as a percentage of sale value, not as a fixed amount), OR
• You repay it in full or in part during the loan term, OR
• The loan term ends (typically 25 years)

The loan is structured as an equity loan, meaning if the property goes up in value, the amount you repay also goes up proportionally. This is the same structure as the original Help to Buy.

Worked example:

• Original project cost: £400,000
• Help to Build loan: £80,000 (20%)
• Property value at sale: £600,000
• Loan repayment: 20% of £600,000 = £120,000

You pay back more than you borrowed because the property has appreciated. Conversely, if the property had fallen in value, you would pay back less.

Difference from Help to Buy

The original Help to Buy scheme (closed to new applications in 2023) was for buyers of new build properties from approved developers. Help to Build is for buyers who are commissioning the construction themselves on a plot they have bought separately.

Help to Build is much smaller in scale and has been more slowly adopted than Help to Buy, partly because self build mortgages are a specialist market and partly because finding a suitable plot is harder than buying off-plan from a developer.

Practical considerations

1. Land first: you cannot apply for Help to Build until you have a plot identified. The scheme does not help with land purchase before you have planning permission.

2. Planning permission: the project must have planning consent. Outline permission is enough at application stage; full detailed permission is required before drawdown.

3. Specialist mortgage: only a small number of UK lenders offer self build mortgages, and even fewer participate in Help to Build. A specialist self build mortgage broker is essential.

4. Build cost overruns: self builds typically run 10% to 20% over budget. Build a contingency into your numbers.

5. Time: a typical self build takes 12 to 24 months from breaking ground to completion. Custom builds can be faster.

Researching plots and area

Property Passport UK shows verified data for every existing property in England and Wales, including sold price history for nearby comparable homes. While the platform does not show vacant land directly (HM Land Registry holds land titles separately), the surrounding sold prices, EPC ratings, flood risk and area data are all useful when researching whether a self build plot is in a viable location. Search any address at [/search](/search).

Check any property in seconds with Property Passport UK

Whether you are buying through Right to Buy, Shared Ownership, First Homes, or at auction, the underlying property data matters. Property Passport UK shows verified EPC, sold price history, flood risk, listed status and tenure for every one of the 19.35 million properties in England and Wales. Search any address at [/search](/search).

Related guides

• Right to Buy explained
• Shared Ownership staircasing
• First Homes scheme explained
• Buying at auction UK guide