Although 3D visualisation is becoming more common in GIS, as of yet, there has been relatively little in the way of 3D editing and analysis functionality especially in the web. This research describes a first attempt at addressing this deficit, documenting a 3D Web GIS with the ability to select, edit, 3D buffer, measure and retrieve attributes. A small user evaluation was undertaken to assess aspects such as usability, consistency and responsiveness. The system developed was implemented using Three.js as a frontend 3D framework and PostGIS as a backend database. The GIS was successful in its execution but detected some issues in requirement of addressing in order to progress. It concludes with recommendations to improve performance and go further with 3D editing.