Esri Building Viewer

"This demonstrates the use of ArcGIS API 4 for JavaScript and Building Scene Layers in a compelling website. The application presents the Turanga library in 3D. The visitor can explore the library by navigating around, and then inside, floor by floor, to discover this amazing building." 

Text via: https://github.com/Esri/building-viewer 

Online Building Viewer: https://esri.github.io/building-viewer/

Related link: https://developers.arcgis.com/javascript/latest/showcase/building-viewer/