DesignBuilder Optimisation

DesignBuilder building design optimisation
Fully-featured optimisation and cost-benefit analysis

The first fully-featured optimisation and cost-benefit analysis tool for building design. Our new optimisation module helps you to identify the design options with the very best combinations of cost, energy and comfort performance.  

By gaining a clear indication of the trade-off between the various design options and their impact on environmental performance you can more easily navigate the complex relationship between design objectives, constraints and possible design options.  With the performance trade-off information at your fingertips it is so much easier to make informed recommendations.


 Example applications

optimisation poster

  • Cost-benefit studies to find the design options that best meet even complex design criteria at any stage of the design process.
    For example see: pdf our poster on the optimisation of a passive building design from the CIBSE-ASHRAE Symposium in Dublin 2014
  • Select the most cost effective lighting, glazing, construction, renewable and HVAC systems even at early design stages.
  • Identify optimal control strategies giving the best combination of environmental and comfort performance for even complex HVAC, natural ventilation, mixed mode system types.


Key features

  • Test over 120 different design variables including glazing type and amount, thermal mass, HVAC, natural ventilation and lighting system type and associated control settings.
  • Select up to 2 design objectives, multiple constraints and up to 10 design variables from a wide range of key performance indicators and variable types..
  • Decide the priority to be placed on the design objectives after the analysis by checking the graphical results. For example in the above graph the red points show the "Pareto Front" of optimal solutions which give the lowest combination of construction cost and operational carbon emissions. The trade off between cost and carbon can be seen very clearly as well as the impact of the decision on lighting system choice. A quick look at this graph might help the designer to home in on the fluorescent lighting system with daylight control as the most cost effective system.


Technical specification

  • Constrained multi-objective optimisation software using the NSGA2 algorithm and EnergyPlus simulations to calculate energy/comfort/carbon emissions.
  • Behind the scenes, the Optimisation module uses advanced evolutionary algorithms through a natural selection process based on improving building performance to help meet the design objectives. The best characteristics are passed on to future generations and the process continues until the optimum designs have been identified.
  • Even "conflicting" design objectives such as "minimise cost" and "minimise carbon emissions" can be analysed simultaneously to provide a set of suggested designs which best meet both objectives.
  • The set of proposed solutions (on the "Pareto front") can be further analysed visually through the graphical outputs and numerically to identify the designs which best meet the design priorities placed on the objectives used. E.g. prioritise on construction cost or comfort performance or perhaps on the balance between cost and carbon emissions.
  • Multiple designs are assessed in parallel on the local machine, on a network simulation server or with an appropriate account on a remote high performance computer.
  • Links to the JESS online simulation service allows fast simulations to be run on the cloud.
  • Apply any selected design from the optimisation to be the new base design.
  • Export results for further analysis using a spreadsheet.



Optimisation is included in the more advanced packages for engineers, Engineering Plus and Pro.


Optimisation also requires both the Simulation and Cost modules if the Carbon and Cost objective functions are to be applied in the optimisation.