In the codes and standards wheelchair lifts are referred to as Platform Lifts. They can travel vertically, Vertical Platform Lift or VPL, or over a stair on an incline,Inclined Platform Lift or IPL. When discussing codes and standards we usually begin with the ADA, however, this is a civil rights law not a building code. 

The ADA Standards for Accessible Design, sometimes referred to as ADAAG or ADA Accessibility Guidelines, provide design professionals with scoping and technical requirements for public accommodations and commercial facilities to be readily accessible to and usable by individuals with disabilities. We are primarily concerned with the aspects of the Guidelines that relate to the built environment that impact people with mobility impairments. Section 410provides some specific rules when using Platform Lifts. 

These Guidelines are very closely harmonized with ICC A117.1 ​“Accessible and Usable Buildings and Facilities”. This standard is referenced by State Building Codes which makes it enforceable by the local authority having jurisdiction (AHJ), so we generally focus on this document when assisting a design professional with an accessibility solution. 

The ADAAG and A117.1contain rules for scoping for when to use a lift, but also rules for how you use a lift. These rules govern the design of the approach to a swing door, use of ramps, minimum platform sizes, etc. 

Finally, there are several other technical standards also referenced by State Building Codes principally ASME A18.1 ​“Safety Standard for Platform Lifts and Stairway Lifts”.

Please note each State may modify any reference standard so is important to begin with your State Building Code.