This document provides an overview of Building Information Modelling (BIM) and its various dimensions. It discusses BIM, the BIM cycle, and dimensions such as 3D, 4D, 5D, 6D, and 7D BIM. For each dimension, it provides an introduction, example software, advantages and disadvantages. The goal of BIM is to create and manage information about a building project using a digital 3D model and shared database. Adding additional dimensions such as time (4D) and cost (5D) allows for improved planning, cost estimation, and sustainability analysis over the lifespan of a building project.