Builders Liens in Australia: Why the Mechanics Lien Does Not Exist Here and What Replaces It

What it is

A builder who has done work on a house and not been paid often hears about a contractors lien or mechanics lien from US sources, then asks whether the same right exists here. The short answer is no. Australia does not have a generalised statutory mechanics lien attaching to land. What Australian builders and subbies have instead is a different toolkit: limited common law possessory liens, retention of title security on materials, security of payment claims, court charging orders and personal property securities registration.

This entry maps the gap between the US concept and the Australian reality, then walks the practical alternatives.

The US mechanics lien for context

In most US states a contractor, subcontractor, materials supplier or labourer who has improved real property can record a mechanics lien on the title to the land. The lien is a statutory creature, secured against the land itself, and ranks behind earlier-registered mortgages but ahead of later interests. If the debt is not paid the lienholder can force a sale.

Australia inherited the English common law tradition. The English law has never recognised a general builders lien on land. The result is that no Australian jurisdiction has imported the US statutory mechanics lien onto real property. A builder cannot lodge a caveat against title simply because they have worked on the house and not been paid.

Possessory liens at common law

Common law in Australia does recognise narrow possessory liens. A repairer who has improved a chattel can hold the chattel until paid, then sell with proper notice. A solicitor can hold a client's file for unpaid fees. These do not extend to land or to a built structure on land.

For a residential builder the practical use of a common law possessory lien is limited. A cabinetmaker who is making cabinets in their workshop can keep them until paid. Once the cabinets are installed in the home, the possessory lien is gone because possession is gone.

Retention of title clauses

The closest functional equivalent to a US materials lien is a retention of title clause in a supply contract. Sometimes called a Romalpa clause after the 1976 English case Aluminium Industrie Vaassen BV v Romalpa Aluminium Ltd, the clause provides that ownership of goods supplied does not pass until the buyer has paid the price in full.

In Australia retention of title is now caught by the Personal Property Securities Act 2009 (Cth). A retention of title clause creates a security interest as defined by the PPSA. To take priority against other secured creditors and against a liquidator if the buyer becomes insolvent, the supplier must register the security interest on the Personal Property Securities Register within the time limits set by the PPSA, usually as a purchase money security interest.

Registration on the PPSR is the single biggest practical protection a materials supplier has. Without it, the retention of title clause is largely ineffective against a liquidator. Suppliers who do not register often lose their goods to the appointed external administrator.

Charges and security interests in contracts

A subcontractor or supplier can also bargain for a contractual security interest in the head contractor's plant, equipment, retentions or book debts. The interest must be registered on the PPSR to be enforceable against third parties. Larger trade suppliers commonly take a general security interest over the corporate buyer's assets in addition to retention of title over the goods.

Where the customer is a homeowner rather than a company, the supplier or subcontractor cannot easily take a registered security over the home itself. A homeowner is not a body corporate, and registering a mortgage requires their cooperation. This is why subbies are rarely secured against the house they are working on.

Charging orders after judgment

A subcontractor or supplier who has obtained a judgment for unpaid work can apply to the court for a charging order over the debtor's real property under state civil procedure rules. In NSW this falls under the Civil Procedure Act 2005 (NSW), in Victoria the Supreme Court (General Civil Procedure) Rules and equivalents in each state. The charging order operates as a charge against the land equivalent to a mortgage. The charge is recorded on title and can be enforced by sale.

A charging order is a post-judgment remedy. It is not available simply because work has been done and an invoice is unpaid. Judgment must come first.

Security of payment legislation

Each state has security of payment legislation modelled loosely on the Building and Construction Industry Security of Payment Act 1999 (NSW). The Acts give a contractor or subcontractor a statutory right to make a progress payment claim, suspend work for non-payment, refer disputes to fast-track adjudication and obtain an adjudication certificate that operates as a judgment debt.

SOP is not a lien on land. It is a payment claim and dispute resolution scheme. It gives the unpaid builder or subcontractor a faster path to a money judgment than ordinary court action. Once that judgment exists, the contractor can pursue charging orders, bankruptcy notices or company winding-up petitions in the usual way.

Caveats on title

A residential builder occasionally tries to lodge a caveat over the homeowner's land claiming an equitable interest based on the building work. State land titles offices reject these unless the caveator can demonstrate a genuine caveatable interest, which a builders progress claim is not. A caveator who lodges without a proper interest exposes themselves to a compensation claim from the registered proprietor under each state's land title legislation.

The only situation where a builder may have a caveatable interest is where the building contract itself grants a charge over the land, signed by the homeowner. Most standard form residential contracts do not include such a charge. Some commercial-style contracts and Master Builders forms have included an express charging clause but it must be properly drafted and signed.

Practical position for an Australian builder

The builder who has not been paid in Australia should reach first for security of payment legislation to crystallise the debt, second to the PPSR for any registered security over goods or equipment, third to ordinary debt recovery once the amount is fixed and last to a charging order over the customer's real property after judgment. The US mechanics lien is not in the toolkit.