1. Introduction

Modern façades, in particular those of office buildings, are highly glazed both to provide daylight and exterior views, which influence occupants’ well-being, and to improve the architectural appearance of buildings. Solar radiation through such façades easily causes glare and overheating, so shading is of vital concern for them. Shading devices aim to prevent excessive heat gains from solar radiation in hot periods, without compromising beneficial heat gains in cold periods or visual comfort in adjacent indoor spaces. Balancing these often contradictory goals is an interesting multi-objective optimisation problem that represents a very active research topic in the field of building energy and daylighting. Overhangs are the simplest and most traditional shading devices that have several beneficial traits: easy installation, high cost-effectiveness, low maintenance and unobstructed view outside. Our goal here is to provide an overview of historical development of the methods for designing overhangs. These methods improved hand in hand with the development of methods for obtaining information about thermal and daylighting behaviour of building models, so this book also represents an overview of the development of building performance simulation tools as related to shading calculations.