A lien is said to be a right “in rem” which means it is a right that exists in relation to certain property:
A lien is a right in rem. It must attach to property.
(Wah Fai Plumbing & Heating Inc. v. Ma, 2011 BCCA 26 at para. 67).
The particular property which a builders lien may attach to is set out in s. 2 of the Builders Lien Act:
[A successful lien claimant] has a lien for the price of the work and material, to the extent that the price remains unpaid, on all of the following:
(d) the interest of the owner in the improvement;
(e) the improvement itself;
(f) the land in, on or under which the improvement is located;
(g) the material delivered to or placed on the land.
(2) Subsection (1) does not create a lien in favour of a person who performs or provides work or supplies material to an architect, engineer or material supplier.
(Builders Lien Act, s. 2).
A claim of lien remains a claim in rem even when security is posted to stand in place of the land the claim of lien was originally filed against:
In my view, Williamson J. was stating the obvious: the claim against the security remains a claim in rem; it is not a claim in personam; the rights of the lien claimant against the original owner are not affected by posting security.
(Q West Van Homes Inc. v. Fran-Car Aluminum Inc., 2008 BCCA 366 at para. 34).
Consistent with the in rem nature of a lien claim, the ultimate remedy (where security is not posted) is to sell the land which stands as security for the claim:
A mechanic’s lien is created by statute and not by the order of the Court which is designated in the statute to enforce it. The statute creates a right in rem and prescribes the method to enforce it. It becomes enforceable by sale under the authority and supervision of the Court.
An action to enforce a mechanic’s lien is not one of debt.
(Triangle Storage Ltd. v. Porter (1941), 56 B.C.R. 422 at 427 (C.A.)).