Recorded Texas Historic Landmarks (RTHLs) are properties judged to be historically and architecturally significant. The Texas Historical Commission (THC) awards RTHL designation to buildings at least 50 years old that are judged worthy of preservation for their architectural and historical associations.

RTHL is a legal designation and comes with a measure of protection; it is the highest honor the state can bestow on a historic structure, and the designation is required for this type of marker. Purchase and display of a historical marker is a required component of the RTHL designation process. Owners of RTHL-designated structures must give the THC 60 days notice before any alterations are made to the exterior of the structure. Unsympathetic changes to these properties may result in removal of the designation and historical marker. To nominate a property, the owner’s consent is required. Refer to the Recorded Texas Historic Landmarks brochure for a full explanation of the designation and its legal requirements.

Criteria
Age: Buildings or other historic structures may be eligible for RTHL designation upon reaching 50 years of age. In some cases, structures older than 50 years that have been altered may be eligible, if those alterations occurred at least 50 years ago and took place during a significant period of the structure’s history.

Historical significance: As with applications for subject markers, it is the responsibility of the applicant to establish, through written and photographic documentation, the historical significance of a structure.

Architectural integrity: In reviewing applications for RTHL designation, the THC considers not only the historic persons or events associated with a structure, but also the architectural integrity of the building or structure. The structure should maintain its appearance from its period of historical significance and should be an exemplary model of preservation. In no case can a structure be considered for the RTHL designation if it has been moved in the past 50 years or if artificial
(aluminum, vinyl, asbestos, etc.) siding applied to its exterior within the preceding 50 years covers and/or alters its historic architectural materials or features.