ESBO (Early Stage Building Optimization) is a simulation tool for building design optimization based on EQUA’s building performance software IDA Indoor Climate and Energy (IDA ICE). ESBO allows you to experiment with different building designs and equipment in order to predict the consequences on energy use and comfort. Room-level and central HVAC systems may be evaluated, as well as glazing, shading and construction materials – all without the need of creating a complete geometric model of the building. ESBO will often be launched or downloaded directly from equipment manufacturers’ or trade associations’ web sites. It will then include tutorials, manufacturer specific products, and special reports focusing on the type of studies that are most relevant for the manufacturer. The result reports may look different for the different manufacturers, but the underlying models are always the same and can be trusted in the same way as all IDA ICE models can. All tools in the EQUA family of building simulation software are based on the same detailed and validated building model, but the lower editions require fewer inputs and are easier to use. ESBO Light is offered for free, while the higher editions require a license. Projects created in a lower edition can always be opened in a higher edition, but not the other way around. In the higher editions (IDA ICE), all details about the models, such as equations and parameters, may be examined in detail. Three types of studies are possible with ESBO: 1. Whole year energy use. 2. Cooling design (or summer overhea ng) according to the ASHRAE heat balance method. 3. Heating design (winter heat load) according to the ASHRAE heat balance method. A database from ASHRAE with climate data for thousands of locations all over the world is available. For each location, three types of climate data that correspond to the different studies are provided: 1. Hourly (IWEC 3) measured climate data that represent a typical year for the loca on. 2. Extremely hot days for each month of the year. 3. Extremely cold days.