Urban areas are the major component of city growth. Urban Built forms information is essential for various GIS applications. In order to build and expand urban areas effectively, there is an active requirement of the existing built-up database. The information pertaining to urban built-up can be relevant to multiple agencies for predicting different criteria-based growths (low rise, high rise, etc.). Furthermore, accurate built-up information is crucial for analysis of urban application such as urban planning, transport related issues, energy demand and renewable energy sources for smart cities development. Earth observation satellite imagery is an encouraging source to extract these built-up areas. However, the automatic built-up extraction of a city from high-resolution satellite data is a familiar challenge in the remote sensing community across the globe. Various remote sensing techniques were analysed based on different high-resolution datasets. 3-D models have been reviewed based on different approaches and compared for implementing renewable energy sources. This study presents a review on various built forms detection and extraction techniques, development of 3D model and its application on energy sector for any city.

Built-up Extraction, 3D City Model, Renewable Energy, Remote Sensing