PA Mechanic's Lien Defense: Terra Firma

When a contractor files a mechanic’s lien against your property, it can feel like you are boxed in. The lien clouds your title, makes it difficult to sell or refinance, and puts you on the defensive. But the Pennsylvania Supreme Court’s decision in Terra Firma Builders, LLC v. King, 249 A.3d 976 (Pa. 2021), provides an important defense that homeowners should know about.

The Rule

Pennsylvania’s Mechanic’s Lien Law, 49 P.S. section 1101 et seq., imposes strict procedural requirements on contractors who file liens. One of those requirements is that the contractor must serve written notice of the filing on the property owner and file an affidavit of service within twenty days. This is the “perfection” requirement under 49 P.S. section 1502(a), which provides that failure to serve such notice or to file the affidavit within the times specified shall be sufficient ground for striking off the claim.

In Terra Firma, the Supreme Court held that if a contractor fails to perfect the lien by filing the required affidavit of service, the property owner can challenge the lien at any time. There is no waiver. Even if the homeowner does not raise the objection until after trial has concluded, the court must strike the unperfected lien.

This is a significant departure from the general rule in litigation that defenses not raised promptly are waived. The Court rested its holding on the text of the statute. Section 1505 expressly provides that failure to file a preliminary objection “shall not constitute a waiver of the right to raise the same as a defense in subsequent proceedings,” and the Court found that the Mechanic’s Lien Law sets no time limit for raising a defect in perfection. Because the right to a mechanic’s lien is purely statutory, it must be pursued in strict compliance with the statute.

Practical Impact for Homeowners

If a contractor has filed a mechanic’s lien against your property, one of the first things to check is whether the lien was properly perfected. If the contractor failed to file the affidavit of service, or filed it late, or served the lien claim improperly, the lien can be stricken.

This defense is available even if you did not raise it in your initial response to the lien action. Terra Firma makes clear that the objection can come at any stage.

Cost-Plus Contracts: An Additional Defense

More recently, in PW Campbell Contracting Co. v. Yetter, No. 910 WDA 2024, 2025 WL 1099644 (Pa. Super. Apr. 14, 2025) (non-precedential), the Superior Court held, on plain-language grounds, that a “cost-plus” contract is not a contract for an “agreed sum” under 49 P.S. section 1503(5). The court expressly declined to decide whether strict or substantial compliance governs the Mechanic’s Lien Law. When work is performed under a cost-plus arrangement, the contractor must provide a detailed itemization of labor and materials and prices charged, as required by section 1503(6), rather than simply claiming a lump sum balance.

If the contractor claims a lump sum on a cost-plus contract without the required itemization, the lien is deficient and can be stricken.

The Bottom Line

Mechanic’s lien litigation in Pennsylvania is a technical area where the contractor’s failure to follow the rules can be your best defense. If you are a homeowner facing a lien claim, do not assume you have to pay. Have the lien reviewed to determine whether it was properly filed and perfected.

If you are a contractor, Terra Firma and Yetter are reminders that strict compliance with the Mechanic’s Lien Law is not optional. A lien that is not properly perfected is no lien at all, regardless of how meritorious the underlying claim.

Contact our office if you need help with a mechanic’s lien dispute.