CitySim Software

The software CitySim is aiming to provide a decision support for urban energy planners and stakeholders to minimize the net use of non-renewable energy sources as well as the associated emissions of greenhouse gases. In developing and testing this software several ambitious aims were reached in order:

  • To support the software users to describe, in an appropriate way, the 3D geometrical buildings forms at the scale of an urban district (comprising several hundreds of buildings) and to attribute these buildings thermo-physical properties in an efficient way using a dedicated XML file format;
  • To simulate the energy demand of these buildings, respecting the stochastic nature of occupants’ presence and behaviour and accounting for a range of commonly used heating, ventilation and air conditioning systems (HVAC systems);
  • To determine the energy supplies of these buildings issued from renewable sources, including the radiation exchange driven by the urban environment, generated by a range of commonly used energy conversion systems;
  • To export standard text files (TSV) to allow the software users to support the analysis of energy performance data in order to identify scope for improving upon buildings’ performance using their favourite graphical tool.

The software CitySim comprises CitySim Solver, a command-line Integrated Solver for simulating the energy demand and supply of buildings for space conditioning, together with the specification of the input buildings’ characteristics (in CitySim XML file format) and the climate files (Meteonorm CLI file format).

Field surveys within residential and non-residential buildings, as well as World-class building energy analysis software such as ESP-r, were used to proceed to the validation of the novel models and algorithms implemented in CitySim. The IEA BESTEST was passed with success.

A graphical user interface is distributed by kaemco (

Direct download CitySim Solver


E. Walter, J.H. Kämpf, A verification of CitySim results using the BESTEST and monitored consumption values, 2nd IBPSA-Italy conference Bozen-Bolzano, 4th – 6th February 2015 [download]