Implied warranties are promises or guarantees implicitly made by a seller of goods or services—even when they are not included in a contract for the goods or services. Such promises are sometimes said to be "made by operation of law."

For example, the implied warranty of habitability in residential construction focuses on the state of the completed structure. In contrast, the implied warranty of good workmanship in residential construction focuses on the builder’s conduct. These two implied warranties parallel one another, and they may overlap.

For example, a builder’s inferior workmanship could compromise the structure and cause the home to be unsafe. But a builder’s failure to perform good workmanship is actionable even when the outcome does not impair habitability. Similarly, a home could be well-constructed and yet unfit for human habitation if, for example, a builder constructed a home with good workmanship, but on a toxic waste site.

Thus, the implied warranty of habitability is more limited in scope, and protects the purchaser only from those defects that undermine the very basis of the bargain. It requires the builder to provide a house that is safe, sanitary, and otherwise fit for human habitation. In other words, this implied warranty only protects purchasers from conditions that are so defective that the property is unsuitable for its intended use as a home.

As compared to the warranty of good workmanship, the warranty of habitability represents a form of strict liability, because the adequacy of the completed structure governs liability—not the manner of performance by the builder.

The warranty of habitability generally may not be disclaimed. And the warranty of habitability extends only to latent defects—it does not include defects that are known by or expressly disclosed to the buyer—even if they are substantial.

Laws regarding the implied warranty of habitability vary from state to state and are often located in a state's statutes.

In Maine, the implied warranty of habitability ensures that a newly constructed residential property is safe, sanitary, and fit for human habitation. This warranty is a legal doctrine that operates by law, meaning it does not need to be expressly included in a contract to be effective. It holds builders to a standard of strict liability for latent defects that affect the habitability of the home, which means that the builder is responsible for the condition of the home regardless of the quality of their workmanship. The warranty of habitability cannot generally be waived by the builder and only applies to defects that are not known to or disclosed to the buyer at the time of sale. On the other hand, the implied warranty of good workmanship requires builders to perform their work to a certain standard. While these two warranties may overlap, the warranty of good workmanship is actionable even if the defects do not make the home uninhabitable. Maine's specific statutes and case law would provide further details on how these warranties are applied and any limitations or exceptions that may exist.