The word “durable” is associated most often with those products we hope to enjoy long after freeing them from their protective packaging. But intellectual property, especially the exclusive rights of copyright protection, enjoys an extended warranty unmatched by anything found on the shelves of your local retailer. And although determining the duration of copyright protection can be perplexing, the complicated scheme of dates and events that permeate many aspects of copyright law can be reduced to a few dependable rules.

Before discussing them, however, definitions of some basic copyright terminology are in order. A work is deemed “created” when it is fixed in a tangible medium of expression, and it is “published” when it is distributed to the public for sale, rental, lease, or lending. Architectural works are created when the drawings are complete, either on paper or in electronic form, but a building can be published long before the actual structure goes up. Even if a work is not published, so long as it is an “original work of authorship,” it is entitled to copyright registration.

Rule No. 1: Life Plus 70 In 1998, Congress passed the Sonny Bono Copyright Term Extension Act, which established that for works created on or after Jan. 1, 1978, registered works, whether published or unpublished, are protected from infringement during the life of the author plus 70 years after his or her death. (Previously, works were protected for 50 years after the author's death.) If the work was created by two or more people and not considered a work for hire (see “All for One,” below), the protection extends for the life of the last surviving author plus 70 years.

Rule No. 2: All for One Works that are created in a corporate setting like an architecture firm— otherwise known as works for hire— are protected for 120 years from creation or 95 years from publication, whichever is shorter. This longer period allows companies to get meaningful copyright protection without the burden of having to catalog the lifespan of the work's creator (or creators). To enjoy these benefits, however, an architecture firm must take the necessary precautions to ensure that its employees and independent contractors are under an appropriate obligation to assign their creative efforts to the firm. For employees, this means defining their scope of employment. For contractors, the firm and the contractor should have a written agreement that assigns ownership of the contractor's rights in the work to the firm. Otherwise, it's possible that an employee or contractor could gain copyright rights to the exclusion of the firm.

Rule No. 3: Ownership Rights During the term of a copyright, the owner—whether an individual or a firm—can exclude others from making copies of the design, displaying the work publicly (except for paintings, photographs, or other pictorial representations of an architectural work), or using the work as the basis to create another, related work (called a “derivative work”). In addition, only the copyright owner has the right to license or assign the copyright. Generally speaking, a license grants only certain rights to a work, whereas an assignment conveys all the rights to the work. This means that an architecture firm can license the right to construct a building but reserve the right to create another building based on the original design. Assigning a work, on the other hand, allows the assignee to assume the role of copyright owner. For the most part, the effect of a license or an assignment is limited by the duration of the underlying copyright.

Remember This Copyright allows your heirs (or your firm) to enjoy the fruits of your labor long after you have shuffled off this mortal coil. But you (or your firm) should also consider that the applicable laws—which are convoluted enough to confound even the most adept attorney—could be protecting a design you assume is in the public domain. When in doubt about the duration of a particular copyright, seek legal counsel.

Jeffrey C. Brown is an intellectual property attorney in Minneapolis.