The Civil Courts Building houses a 32,000 sq.ft. law library on the 13th floor. This library houses an extensive historical and active collection of law related materials. The library functions as a central resource for the St. Louis law firms. In 1996, WTA began a design process that resulted in the complete renovation of the 13th floor and the 13th Mezzanine. The existing architecture, some of the most ornate in the city, had to be respected while implementing new technology in a space that has not been renovated since its construction 70 years ago. The project included:

• A new HVAC system providing a new controllable system with emphasis on quiet operation and integration with the existing architecture. To minimize deterioration of the collection special care was taken in design of the humidification system.
• Replacement of all existing plumbing systems including making provisions for ADA compliant restrooms, new water service, and piping replacement.
• A new library fire protection system requiring coordination of furniture and architectural features.
• A total replacement of the electrical branch circuiting and distribution system to accommodate the increasing use of technology.
• Provisions for communications wiring throughout the library. This provides communication for in-house needs but also provides a modem connection for visiting attorneys to access the WWW and their office servers.