“Section 14(1) of the Construction Act provides that, “a person who supplies services or materials to an improvement for an owner, contractor or subcontractor, has a lien upon the interest of the owner in the premises improved for the price of those services or materials.”
The lien creates an interest in the land in favour of those who supply materials or services, thereby creating security. This operates to prevent the owner from receiving improved land without making payment for the improvement. If the lien is unsatisfied, you can take private owner’s property, sell it and payback the lien. This is especially important to subcontractors who have no direct contract with the owner (and, therefore, no right to bring an action for payment under a contract).
A person’s lien arises and takes effect when the person first supplies services or materials to the improvement.”