Building Energy Software Tools
Formerly hosted by US Dept. of Energy    


Reviews 5

DesignBuilder provides advanced tools to model and quantify building performance in an easy-to-use interface. This enables your whole team to use the same software to quickly develop comfortable and energy-efficient building designs from concept through completion and into building operation.

DesignBuilder provides a fully-integrated set of high-productivity tools to assist with sustainable building design and performance analysis. Many types of energy and comfort analysis can be undertaken seamlessly from one base model, enabling you to meet more of your client needs and extract the maximum value from the time you invest in your modeling activity. Leading architects, engineers and energy modelers across the world use DesignBuilder to quantify the impact of their design strategies on building environmental performance. Or simply to demonstrate compliance with building regulatory codes and certification schemes such as LEED, Energy Star and BREEAM.

Link with BIM solutions to evaluate different alternative design scenarios for HVAC systems and controls, facades, lighting, renewable technologies all in one place, adjusting as you go according to client requirements.

High quality technical and rendered outputs help communicate findings to clients in a way they can easily understand. Key performance indicators such as energy consumption, peak heating and cooling loads, carbon emissions, thermal comfort, daylight availability and cost can be provided throughout the design process in both naturally ventilated and air-conditioned buildings.

If you are in the business of designing high-performance energy-efficient comfortable buildings, quantifying and evaluating energy conservation measures, or complying with codes and certification schemes then DesignBuilder can help you do it more quickly.

Expertise Required: 

DesignBuilder is the easiest mainstream building performance analysis software to learn. Beginners and students can learn DesignBuilder faster than with comparable tools, becoming productive with the software more quickly. These productivity benefits continue as the user becomes familiar with the more advanced features of the software.


Architects, engineers, building designers, building scientists, academic research and teaching departments. DesignBuilder is the easiest and most powerful software available for teaching students building energy simulation. Its combination of power and ease of use is unmatched in the industry.


OpenGL solid modeler, allows building models to be assembled simply by positioning, stretching and cutting 'blocks' in 3-D space. Realistic 3-D elements provide visual feedback of actual element thickness and room areas and volumes. Building geometry can be imported from 3D BIM models, drawn freehand or from imported 2D floor plans.

DesignBuilder’s unique data management system enables you to input the most common data at the site, building, block, zone or surface levels so that it is then automatically set for all attributes in the levels sitting below that. This significantly reduces the amount of data you need to input, reducing modeling time and reducing the risk of data input error.


Internal air, mean radiant and operative temperatures and humidity.
Comfort output including temperature distribution curves, ASHRAE 55 comfort criteria, CIBSE TM52 and TM59, Fanger PMV, Pierce PMV ET, Pierce PMV SET, Pierce Discomfort Index (DISC), Pierce Thermal Sens. Index (TSENS), Kansas Uni TSV, under-heating and overheating hours distribution curves.
Site weather data.
Heat transmission through building fabric including walls, roofs, infiltration, ventilation etc.
Heating and cooling loads.
Emissions of CO2 and other pollutants.
Heating and cooling plant sizes can be calculated using design weather data.
Data can be displayed graphically or in tabular form and can be exported in a range of formats to spreadsheet and custom reports. It is also possible to visualize surface and zone data rendered on the model using false colors.
Optimization outputs allows you to pinpoint the options with the very best combinations of cost, energy and comfort performance and to navigate the complex relationship between design objectives, constraints and possible design options.
ASHRAE 90.1 Appendix G 2007 and 2010 Performance Rating Method reports to support LEED EAp2 and EAc1.


DesignBuilder is an excellent choice for early-stage modeling to test building design concepts, allowing you to easily develop those concepts as the design evolves and the model matures. With DesignBuilder you really can develop your early-stage model all the way through to detailed design and certification without having to rip it up and start again.

The DesignBuilder concept of “Simulation Made Easy” is exemplified by its ability to very quickly set up an early-stage massing model using quick geometry creation and editing tools, data input templates and simplified methods of HVAC and ventilation simulation. Detail is then added to the model as the design matures by finessing the geometry, selecting more advanced HVAC and natural ventilation options and increasing the model detail.

DesignBuilder’s fully-integrated approach enables you to develop one core model and use it to run a variety of analysis types using different engines (EnergyPlus, Radiance, or CFD) without the need to import and export the model between different tools and programs. LEED daylighting and energy efficiency credits can be quickly calculated and reported after creating the ASHRAE 90.1 baseline building and HVAC system through an automated process.

For more advanced users, DesignBuilder’s unique EMS scripting tools can be used to customize the simulation at run-time. Custom versions of EnergyPlus can be used with DesignBuilder, allowing researchers to improve productivity by combining the GUI ease-of-use and speed benefits with "under the hood" modifications to the EnergyPlus source code.

United Kingdom
Major Capabilities: 
Whole Building Energy Simulation
Load Calculations
Parametrics and Optimization
Ratings and Certificates
Air Flow Simulation
Building Type: 
Multi Family
Reduced for Non-Commercial/Academic Use
Free To Try
Help and Support: 
Free Email Support
Free Chat/IM Support
Last Software Update: 
25 January 2018
Last Entry Update: 
19 September 2018
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I've used DesignBuilder for the last 10 years. Initially, it's capabilities were marginal, though helpful.
Since then, DB has steadily improved and is now my mainstay for almost every project. Their "hierarchical" data structure and input color-coding makes assigning inputs MUCH more straightforward and easier to check - this is a key element that makes model preparation much faster and error-free. In addition, they've added forward-thinking tools such as 2-axis optimization and continue to develop other capabilities.
Just as crucial, the DB support has been outstanding for the entire period, as has been their receptivity to suggestions!

Submitted by Brazil on

DesignBuilder is an incredibly user friendly software which we have been using for LEED certification and energy certificates as long as many other applications related to building performance. I strongly recommend it for advanced and new energy modelers who care about building performance.
A must use software.

I've been using DesignBuilder in a couple of roles for about 8 years. It is currently the central tool for my core work. I have also used IES and HAP a fair amount.

As a front-end to EnergyPlus and Radiance, DesignBuilder has a lot of power but is reasonably accessible for those finding their way for the first time.

As mentioned by others here, the support is really good and the software has come a long way in terms of capabilities and also reliability.

Future developments look promising and I'm looking forward to continuing to work with the package as it continues to grow.

Outils de simulation ergonomique de l'esquisse au détail.
Après 12 ans de pratique, je résumerai ce logiciel ainsi.
DesignBuilder a l'avantage de proposer, autour d'une maquette 3D, toutes les simulations nécessaires à l'évaluation énergétique et de confort d'un bâtiment. Son modèle de données par héritage et prédéfinitions ciblées permet des saisies productives, les rendus visuels sont excellents et l'usage des moteurs de calcul internationaux (EnergyPlus, Radiance, OpenFoam) lui confère un atout de poids.
Par ailleurs DesignBuilder évolue régulièrement avec de nouvelles fonctionnalités soit d'ergonomie, soit de simulations avancées, rendant l'investissement initial encore plus rentable.

I'm an Architect specialized in Green Building Design. I help real-estate and construction companies find the best design for Energy performance, wellbeing and capital costs. Designbuilder is the best software in the market to run Energy simulations using optimization in an easy and precise way. I just love the fact that your same energy model can check not only Energy Performance, but also Visual Comfort and Air Quality. This process saves a huge amount of time and gives us confidence for affordable, sustainable and healthy buildings toward Net Zero Designs.