What's new in v5

DesignBuilder v5.5 adds a substantial set of new features and improvements compared with v4 including significant productivity improvements for LEED and ASHRAE 90.1 PRM work, Climate Based Daylight Modelling, graphical output of simulation results rendered on the model and new Scripting tools to allow EnergyPlus simulations to be customised.  

Other highlights include Combined Heat and Moisture Simulation, Radiant surface heating/cooling, new Cost Modelling tools and a Fluid to Fluid heat exchanger component which opens the door to modelling a wide range of new HVAC systems.

To find out about upgrading to v5 see our Upgrade page.

Download v5.5

The list below summarises the main improvements made since v4. 

UK Compliance and Certification


  • New graphical output of simulation results rendered onto the 3-D model using false colours.
  • Generate movies of the new graphical data plots to show time-varying outputs over the model.
  • Thermal comfort reports for CIBSE TM52 and TM59.


  • Climate-based daylighting assessment with Spatial Daylight Autonomy (sDA), Annual Sun Exposure (ASE) and UDI outputs generated via the Daysim simulation engine.
  • Specular reflection of daylight now allows modelling of light shelves etc.
  • New “Perez all weather” options for defining sky illuminance.
  • Diffusing glazing can be modelled in Radiance and Daysim.
  • More flexible and accurate modelling of working planes.
  • Various new options for more accurate BREEAM daylighting reports.

3-D Modeller

  • gbXML export provides full 2 way interoperability with other modelling tools.
  • Import 2-D elevation drawings to help with drawing facades.
  • New stretch and rotate tools allow existing openings to be easily modified at both building and surface levels.
  • New option to show the current block/zone in the context of the rest of the building.
  • Selective ghosting of blocks allows “buried” blocks to be accessed for geometric editing.
  • Direct input options for absolute internal/lighting gains and number of occupants without reference to floor area.
  • Improved gbXML BIM import now fully supports courtyard voids.
  • Improved filters for fast data loading from templates.


  • Various improvements and fixes to ensure that the rendered view accurately represents the data used in the simulation.
  • Faster performance with less delay when moving to the Visualisation screen.

EnergyPlus Simulation

  • EnergyPlus v8.6 with various improvements and fixes.
  • Combined Heat and Moisture Simulation using HAMT or EMPD algorithms
  • Improvements to the link to the JESS online simulation service providing fast cloud simulations through the Simulation Manager.
  • Ground domains allow 3D heat loss to the ground to be simulated with options for basements and slabs.
  • Options to model 2 new adaptive comfort natural ventilation control modes: CEN 15251 Adaptive and ASHRAE 55 Adaptive.
  • Multi-state SageGlass electrochromic windows with a range of glare control options.
  • Thermochromic glazing.
  • Exterior surface baffle with natural ventilated cavity.
  • IGDB window panes database updated to v52..


  • EMS Scripting tools allow the behaviour of HVAC equipment, controls and facades to be customised. Productivity features include:
    • A range of DesignBuilder extensions to the standard EnergyPlus EMS syntax allow fully portable scripts to be written. Scripts written for one project can be used on other projects and shared through the public script repository.
    • Load fully formed actuator, sensor, variable, output statements from easy to use dialogs.
    • Read building, zone or surface settings from the DesignBuilder model to populate data within the script.
    • Colour syntax highlighting in the scripting window helps readability.
    • Parametric variables linked to optimisation allow EMS settings to be optimised to best meet design objectives.
    • Several new DesignBuilder extensions to EMS scripting syntax allow looping through zones, surfaces and openings with optional arguments providing various ways to filter.
  • FMU/FMI interface for co-simulation with external applications. Applications for FMU include linking occupant behaviour models or CFD simulations with EnergyPlus.

LEED and ASHRAE 90.1

A range of new tools to help assess buildings through the ASHRAE 90.1 Appendix G 2007 and 2010 Performance Rating Method:

  • Fully automatic baseline building generation with proposed and baseline buildings both included in the same model and improvements in support for complex surface and window shapes.
  • Guided semi-automatic baseline HVAC system generation wizard including auto-assignment of AHUs and single-zone systems.
  • Automatic parallel simulation of the 4 rotated baseline buildings and averaging of the results.
  • On screen comparison of proposed and baseline building cost and energy simulation results.
  • All constructions, materials, glazing systems, activities, lighting and HVAC systems required for ASHRAE 90.1 2007 and 2010 are included and automatically set based on the climate zone within the DesignBuilder modeller.
  • Support for LEED 2009 and v4.
  • Links to LEPORT online documentation preparation system for EAc1, EAp2, Table 1.4 reports.


  • Fluid to Fluid Heat Exchanger allows heat to be exchanged between plant/condenser loops.
  • Radiant surfaces with option for reversible heating/cooling in same surface.
  • Zone water-to-air heat pumps.
  • Waterside economisers.
  • New chiller types: Absorption, Reformulated EIR and Indirect absorption.
  • Chilled water storage.
  • VAV Outdoor air terminal unit.
  • Dedicated outdoor air sizing options for HVAC zones and zone groups.
  • New options for mechanical ventilation modelling in heating and cooling sizing calculations.

LZC and Renewables

  • Building integrated photovoltaic (BIPV) generation for all wall, roof and glazed surfaces.


  • New tool applies optimal design properties to the base building design.
  • New UNIFORMAT II and NRM1 cost KPIs for setting project financial objectives and constraints.


  • Major overhaul of the construction cost modelling calculations with new options to support the NRM1 and UNIFORMAT II standards.
  • HVAC systems can be costed based on heating/cooling capacity as well as by floor area.
  • Additional capital cost KPIs for use in design optimisation studies.

Building Life Cycle Analysis (LCA)

  • Direct link to the One Click LCA tools for advanced long term environmental impact analysis.


  • New installer with improved reliability.
  • Hundreds of other minor improvements and fixes


Find out about Upgrading to v5.


Download v5.5