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 New York, the implied warranty of habitability is a legal doctrine that ensures residential properties sold or leased are suitable for living. This warranty is automatically included in every residential lease and cannot be waived by the tenant. It requires that the property meets basic standards of safety, sanitation, and is fit for human habitation. If a landlord fails to maintain these standards, tenants may have the right to withhold rent, make necessary repairs and deduct the cost from the rent, or in extreme cases, terminate the lease. The implied warranty of good workmanship, on the other hand, applies to the construction of new homes and renovations. It holds builders to a standard of care in the construction process, ensuring that the work is performed competently and results in a structurally sound and properly functioning home. While the warranty of habitability focuses on the end condition of the living space, the warranty of good workmanship addresses the quality of the construction process itself. Both warranties provide recourse for buyers and tenants when their expectations of quality and safety in housing are not met, although they address different aspects of the housing quality.