The document discusses a mobile application called Map4Data that was created to conduct field surveys for building typology and energy efficiency data collection. The app allows surveyors to view buildings on a map, select individual buildings, and fill out property forms with attributes like construction period, height, use, and energy refurbishment level. It sources data from existing topographic and cadastral databases but aims to verify and supplement incomplete or inaccurate records through field surveys. The document provides instructions on using the app and an example of survey progress with over 1,000 buildings surveyed over 27 hours.