DesignBuilder provides advanced modelling tools in an easy-to-use interface. This enables the whole design team to use the same software to develop comfortable and energy-efficient building designs from concept through to completion.  

DesignBuilder v5 is released!

DesignBuilder v5 adds a substantial set of new features and improvements including significant productivity improvements for LEED and ASHRAE 90.1 PRM and a new set of scripting tools to allow EnergyPlus simulations to be customised.  Other highlights include Combined Heat and Moisture Simulation and a new Detailed HVAC fluid to fluid heat exchanger component which opens the door to modelling a wide range of new systems. Learn more

for Engineers   for Architects   for Energy Assessors

DesignBuilder for Engineers Our powerful simulation toolbox lets you model HVAC, daylighting, airflow, cost, energy and carbon. Optimise your solutions to meet design goals and maximise the benefits for your clients.


DesignBuilder for Architects Assess energy efficiency and carbon performance during early stage design. Visualise solar shading and explore designs to maximise comfort and the benefits of daylighting and natural ventilation.


DesignBuilder for Energy Assessors Be cost efficient and competitive by using the quickest and easiest to learn software for generating UK EPCs and Part-L2 building regulation compliance reports using SBEM.

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  • I have watched the steady progression of DesignBuilder for the last 10 years or so, and having seen recent improvements in DesignBuilder’s HVAC and LEED modeling I decided to attend their training. I was both surprised and pleased to find how easy to use DesignBuilder is compared to the other similar tools I’ve tried, especially given the power and flexibility offered by the underlying EnergyPlus, Radiance and CFD engines. I’m really pleased that after a week’s training I feel ready to produce accurate results and outputs for loads and sizing calculations and energy analysis. The ability to also undertake fully-integrated daylighting and CFD analysis from the same model you use for loads and thermal simulations is also a very big plus point.

    David Ellis PE, Virginia 22102, USA
  • We have had a very positive experience with DesignBuilder this semester as it was the first year we shifted from our previous simulation software to DesignBuilder. Our students seem to spend less time on learning the software and more on actually understanding the results and being able to analyse them.

    Dr Shahaboddin Resalati - Senior Lecturer in Sustainable Architecture and Building Physics Architectural Engineering Group, School of Architecture, Oxford Brookes University, UK
  • The graphical user interface of DesignBuilder is comprehensive and intuitive, allowing us to model complex buildings simply and quickly. The data management structure (data hierarchy and inheritance) allows us to assign model data quickly and accurately, improving our efficiency. The power and flexibility of EnergyPlus, the underlying simulation engine, enables us to model a building in fine detail where required so that we can accurately analyse its performance. This is particularly helpful when calibrating the model with actual energy consumption to obtain a reliable close match when assessing potential improvements and energy conservation measures.

    Alessandro Righi, architect and researcher at IUAV - Laboratory technical physics
  • We utilised DesignBuilder software to carry out detailed natural ventilation assessments on buildings at our UK gas plants in order to demonstrate compliance with hazardous area regulations. First of all I would like to praise the initial support received from DesignBuilder staff, who were extremely knowledgeable and provided a welcoming point of contact for support and advice. Having used the majority of the alternative building simulation software packages on the market, I found without a doubt DesignBuilder the most user friendly and enjoyable to use. The modelling program itself is fantastically simple allowing even complex buildings to be developed quickly and easily. The user interface of the calculation part of the software is well thought out and the results outputs are graphical and concise. Within a few hours I had got to grips with the software and obtained the results I desired. It has allowed Shell to present compliance to regulating authorities, who were also impressed with the visualisation displays and graphical outputs. I fully endorse DesignBuilder, and in particular how easy it was to learn and use compared to similar building simulation software on the market.

    Iain Begg, Senior HVAC Engineer, Shell Projects and Technology Group, Aberdeen, Scotland
  • DesignBuilder’s clear, well-structured layout and intuitive help system makes it a much simpler tool to learn and use, and compared to other simulation packages the creation of professional-looking geometry is much easier. The ease of use extends to other areas of the program such as thermal bridging analysis and setting up HVAC systems, and the capability to easily model adjacent ground conditions is very useful. A very important aspect of our work is optimisation, and DesignBuilder seems to be the only software that currently provides this functionality. We are encouraged that the development team have taken some of our functionality and user efficiency suggestions on board for the next release. We are already using DesignBuilder for research, and for the above reasons we think it is a tool that our students will find easier to use so we will be using it for teaching next academic year.

    Professor Ljubomir Jankovic, Birmingham School of Architecture, Birmingham City University
  • We decided to go out and measure some natural light levels in buildings that we have access to.... One building was our own office, and the other was a green building we worked on which will be tenanted in 2 weeks so we had a chance to take readings in the same environment for which we simulated. I am happy to say that the DesignBuilder results are very close to what we measured... What impresses me is that if we measure a value of 250 lux at 3m from the facade, DB returns similar values. This means that if we say that 40% of a building's usable area will have lux levels of 250 or above, then the measured results correlate with that. ... It certainly makes us confident in the results we give to clients.

    Warren Gray, Mechanical Engineer, Solid Green Consulting
  • First of all I would like to thank you very much for the outstanding online training that you made possible for our team. I was very happy that we could join with three people in an online training that offered us as an outstanding value. ... The course with DesignBuilder is going very well and we have some great feedback from the students.... Your data entry GUI makes it easy for students not only to “accept defaults” but to experiment. In addition your online help is extremely thorough and you present not only the theoretical background but also offer great links to the reference. You might not realize what a powerful learning tool this is; but it is. We think you have created something very valuable and we are looking forward very much to where your company goes from here... Thanks again for your great support.

    Dr Manfred J. Zapka, University of Hawaii
  • Gold stars all round .... Many thanks again for the high quality of customer service I receive from all at DesignBuilder, it is quite refreshing and a credit to your company.

    Mark O’Neill, DM Hall LLP, Glasgow, Scotland

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Case Studies