Who this is for
- First home buyers buying land and building, with a limited deposit and a family member willing to support the application
- Parents or relatives thinking about guaranteeing a build who want to understand the exposure before they sign
- Couples building on land a relative has gifted or sold to them, where the family wants to limit the guarantee
- Buyers comparing a family guarantee with a smaller-deposit approach under a government scheme
Why a guarantor construction loan is different from a guarantor purchase
A standard guarantor loan supports the purchase of a finished home. A guarantor construction loan supports a project: land, a building contract and a series of staged payments. The security changes as the house goes up, so the guarantee has to be planned around the whole build, not just the first day.
If you only need the basics of how a family guarantee works on an existing home, start with our guarantor home loans guide. This page is about what changes when the property does not exist yet.
How a family guarantee building loan is structured over land and build
In a family guarantee building loan, a relative offers the lender extra security, commonly the equity in their own property, to support your borrowing. Lenders vary in how they do this. Some ask for a limited guarantee capped at a set amount, and others treat the guarantee as covering the whole facility. Your broker will explain what a suitable lender offers before you commit.
The guarantee usually sits behind the entire construction facility, so your guarantor's exposure begins with the first draw, whether that is the land settlement or the first building stage. That is why the timing of land purchase, the building contract and the loan approval all matter to the family, not just to you.
Guarantors are commonly encouraged to get independent legal and financial advice before signing. It is a serious commitment and worth doing properly.
Guarantee release after the completion valuation
Many families ask when the guarantee can come off. Release is not automatic. A lender may consider it once the build is complete and a fresh valuation confirms the finished home's value, and once your loan balance sits at a level the lender accepts against that value. Some lenders also want to reassess your income on its own.
Policies, fees and timing for release vary between lenders. Ask about them at the start, in writing, so the guarantor knows what to expect and roughly when. The as-if-complete valuation used at approval and the completion valuation can differ, which is another reason to keep a buffer for cost increases; our guide to construction cost overrun loans explains how that risk is handled.
5% deposit construction loan: family guarantee or government scheme?
These are two different things, and people often mix them up. A family guarantee uses a relative's property as extra security. The Australian Government 5% Deposit Scheme, described on firsthomebuyers.gov.au (the scheme formerly known as the First Home Guarantee), is a government program that lets eligible first home buyers purchase with a minimum 5% deposit, or 2% for single parents, with no income caps, for a house, townhouse or unit, existing or new build.
Whether a particular land and build project fits that scheme, and which lenders take part, depends on the scheme rules and the lender. Treat a 5% deposit construction loan as something to confirm with your lender and the scheme's own website, not something to assume. A family guarantee can sometimes be the alternative when the scheme does not fit your situation.
How Mortgagefy helps
We look at your deposit, income and the build, then explain whether a family guarantee, a smaller deposit approach or a mix suits you. Lending policy varies, so your broker matches you to a suitable lender once the numbers are clear.
Model the repayments with our Sydney home loan calculators, and see how a build differs from a standard purchase in our first home buyer construction loan guide. Our construction home loans hub covers the wider picture, including vacant land loans and house and land packages.
How it works: 4 simple steps
Map the deposit and the family position
We review your deposit, income, the land and who the guarantor is, and whether a guarantee, a government scheme or both fit.
Match a lender
Guarantee structures vary, so we shortlist lenders whose approach to limited guarantees and release suits the family.
Assemble the build pack
Contract, plans and approvals are prepared in the format the lender expects, and the guarantor gets time to take independent advice.
Build, draw and plan the release
Funds are released in stages. After completion we help you ask about a release valuation when it makes sense.
Get your personalised answer in 2 minutes
Free, no obligation. We'll match you with the right lender for your situation.
Guarantor construction loan questions
How does a guarantor construction loan work?
Can a family guarantee building loan cover both the land and the build?
When can the guarantee be released after construction?
Is a family guarantee the same as the government 5% Deposit Scheme?
Can I get a 5% deposit construction loan with a guarantor?
What should my guarantor do before signing?
Government scheme details checked on firsthomebuyers.gov.au on 1 October 2026. Other information is general, reviewed 1 October 2026. Policies, government schemes and lender participation may change.
Confirm current requirements and lender participation directly with your chosen provider before applying.
This information is general in nature. Policies vary by lender and change frequently. Confirm current requirements with your chosen provider and seek professional advice.
Get your free guarantor construction loan assessment
We map out the guarantee, the build stages and the release plan so your family knows what to expect before anyone signs.