Current Features

OpenStudio SDK is constantly being improved, with a less stable developer release available every 2 weeks and a stable major release twice per year. The features that are available in the current major release are described below. To learn what is coming in the future, see the Planned Features page.

As of OpenStudio SDK Version 3.0.0

Building Constructions and Materials

  • Specify default materials for each type of surface and subsurface (ext walls, windows, floors, etc.) in building
  • Specify detailed or simple window properties
  • Built-in library of building constructions (walls, windows, doors, floors, etc.) for all DOE reference building types and vintages (pre-1980, 1980-2004, and 2004) plus ASHRAE 189.1-2009, ASHRAE 90.1-2007, and ASHRAE 90.1-2010
  • Online library of building materials and their modeling properties from ASHRAE Handbook

Building Loads

  • Specify people, lights, plug loads, gas loads (cooking, etc.), steam loads, internal mass, water using equipment, ventilation requirements, and infiltration
  • Can input loads per-area or add actual quantities to accommodate schematic and detailed design
  • Built in library of space types (loads and associated schedules) for DOE reference buildings for all vintages (pre-1980, 1980-2004, and 2004) plus ASHRAE 189.1-2009, ASHRAE 90.1-2007, and ASHRAE 90.1-2010
  • Can apply loads in one place (space type) and apply throughout the building


Hot, Chilled, and Condenser Water Systems
  • Boilers (all fuels)
  • District heating and cooling
  • Set-temperature heating/cooling source
  • Single, two-speed, and variable-speed cooling towers
  • Single and two-speed fluid coolers and evaporative fluid coolers
  • Chillers (electric, absorption, indirect absorption)
  • Vertical and horizontal ground heat exchanger (bore fields & trenches for ground-source heat pumps)
  • Bypass pipes
  • Constant and variable speed pumps, both individual and headered
  • Fluid-to-fluid heat exchangers (for primary/secondary pumping and waterside economizers, etc.)
  • Hot, Chilled, and Condenser Water System Controls
  • Scheduled, OA reset, high and low with deadband, and follow OA setpoint controls
  • Staging of equipment (based on load range, part-load, sequential, etc.)
  • Solar hot water (with and without storage and integrated PV)
  • Pipes (indoor heat loss, outdoor heat loss, or adiabatic)
  • Load profile (model plant behavior with loads from a schedule)
  • Ice and chilled water storage
  • Water-to-water heat pumps
Air System Components
  • Supply and return plenums
  • Unitary equipment
  • Dual-duct systems
  • Changeover bypass (VVT) systems
  • Multi-stage unitary equipment (used with staged thermostats)
  • Outdoor air intake with economizers (all types) and damper control
  • Chilled water cooling coils
  • One-speed, two-speed, multi-speed, and variable-speed DX cooling coils
  • One-speed, multi-speed, and variable-speed DX heating coils (heat pumps)
  • Water-to-air heat pumps
  • Gas, electric, hot water, and DX (heat pump) heating and/or preheat coils
  • Variable and Constant Speed Fans
  • Steam humidifiers (electrically powered) used with zone humidistats
  • Direct and indirect evaporative coolers
  • Sensible and latent heat recovery
  • VAV-Reheat and CAV-Reheat terminals (gas, electric, and hot water reheat coils)
  • VAV terminals without reheat
  • Series and parallel fan powered boxes with reheat (all fuel types)
  • Diffusers
  • Chilled beams (active and passive)
  • Four-pipe induction terminals
Air System Controls
  • Demand-controlled ventilation
  • Night-cycle controls (whole system and/or terminal fans)
  • Scheduled, OA reset, SAT reset, and follow OA setpoint controls
  • Single-zone VAV system control (one control zone, many slaves)
  • Optimum start control
Zone-level Heating and Cooling Systems
  • Unit heaters (all fuels)
  • Unit ventilators
  • Energy recovery ventilators
  • Dehumidifiers
  • Low temp radiant heating (electric, variable and constant flow water)
  • Low temp radiant cooling (variable and constant flow water)
  • PTAC (DX cooling + fan + all heating fuels)
  • Water-source heat pump
  • Air-source heat pump
  • Exhaust fans
  • Four pipe fan coils (may be supplied via DOAS system)
  • Electric and hot-water baseboards
  • High temperature radiant heaters (gas and electric)
  • Zone-to-zone transfer air (zone air mixing)
Variable Refrigerant Flow Systems
  • Condenser plus zone-level terminals
Commercial Refrigeration
  • DX Refrigeration Systems
  • Cascading DX Refrigeration Systems
  • Fluid-filled DX Secondary Refrigeration Systems
  • Cases
  • Walk-in freezers
  • Compressors
  • Air, water, and evaporatively-cooled condensers
  • Liquid-suction heat exchangers and mechanical subcoolers
  • Heat-recovery to domestic hot water systems (desuperheater)
  • Heat-recovery to unitary air systems (desuperheater)
Domestic Water Systems
  • Hot Water Heaters (all fuels, including heat pump)
  • Equipment that uses warm water (showers, faucets, etc.), can specify mixed water temp
  • Equipment that uses cold water only
  • Recirculation, no pump, or instantaneous water heaters


  • Run daylighting analysis using Radiance, state-of-the-art ray-tracing daylight simulation engine without making a separate model
  • Lights in the EnergyPlus model controlled based on daylight available per Radiance

Custom Controls

Within EnergyPlus, advanced controls that are not built-in can implemented utilizing the EnergyManagementSystem (EMS) suite of objects. This involves defining Sensors and Actuators that interact with building parameters through Programs which are written in the EnergyPlus Runtime Language (ERL), which is based on a common building-controls language. OpenStudio SDK supports the creation of EMS programs.

Location-Specific Information


  • Full lifecycle costing (NIST Handbook 135 compliant) including built-in EIA fuel escalation rates and inflation
  • Adjustable analysis period length
  • Capital, recurring O&M, salvage, and replacement costs
  • Lifecycle is adjustable per-cost (IE windows can last longer than lamps)
  • Utility rates can include time-of-use, demand charges, ratchets, seasonal values, etc.
  • Utility rates for Xcel Energy CO pre-made; users pick from list

Import and Export Options

  • IDF import (geometry, constructions, loads, thermal zones, and schedules only)
  • IDF export (full model including HVAC)
  • gbXML import (geometry, constructions, thermal zones, and schedules only)
  • gbXML export (geometry, constructions, and thermal zones only)
  • SDD import (simulation format - full model including HVAC)
  • SDD export (input format - geometry, constructions, and thermal zones only)
  • IFC import (geometry only)

Analysis of Existing Buildings

  • Enter utility bills for all fuel types in building
  • Run model using actual weather data (AMY)
  • Automatically compare model results to bills and shows goodness-of-fit by fuel type
  • Automatically show whether goodness of fit meets common calibration standards (FEMP, ASHRAE)


  • Space types (people, lights, equipment, ventilation, infiltration, schedules) for DOE reference buildings for all vintages (pre-1980, 1980-2004, and 2004), ASHRAE 189.1-2009, ASHRAE 90.1-2007, and ASHRAE 90.1-2010
  • Building constructions (walls, windows, doors, floors, etc.) for DOE reference buildings for all vintages (pre-1980, 1980-2004, and 2004), ASHRAE 189.1-2009, ASHRAE 90.1-2007, and ASHRAE 90.1-2010
  • Extensive online library of building materials from ASHRAE Handbook of Fundamentals
  • Extensive online library of weather files and design day conditions

Parametric Analysis

  • OpenStudio Measures provide reliable and repeatable mechanism to apply ECMs to models
  • Eliminates ambiguity and user error; all rules encapsulated in Measure itself
  • More than 130 Measures available online and always growing
  • Write Measure once and apply to many projects
  • Perform complex ECMs, like full HVAC replacement, easily
  • Edit user inputs to control how Measure modifies the model
  • Creates meaningful results, ready for inclusion in reports to clients.


  • Measures can be used to check for common modeling errors
  • Users don't have to understand to use; gives expert review to junior modelers more cheaply
  • Automate key checks for Utility Regulators to keep up quality
  • Lower time spent by reviewers on mundane checks; frees time to focus on real issues


  • Measures can be used to create custom reports in HTML format (view in any web browser)
  • Allows users to quickly visualize and summarize data for different audiences
  • Reports are shareable via email
  • Reports can be simple or highly interactive

Cloud Computing

  • Any user with an Amazon account can run simulations on cloud with 1 click
  • Very cheap vs. engineer's time (16 simulations in parallel for ~$2.00/hr)
  • Can run up to 300 simulation in parallel (costs scale in 16-processor increments)
  • Enables small firms to access cloud computing without upfront hardware costs

Share Modeling Best-Practices

  • Online database called BCL (Building Component Library) can be used to share Measures
  • BCL can be used to share building components
  • Instantaneous world-wide distribution and updating of content
  • Allows Utilities to ensure uniformity and best-practices across many EC firms


  • Interactive PDFs describing each Application
  • Measure writing guide
  • Lifecycle costing guide
  • Documentation of all modeling commands (SDK) online, updated bi-weekly


The following applications are available to work with the OpenStudio SDK installation:

Data Viewer

  • View the detailed timeseries simulation results
  • Create interactive line graphs and heat maps

Parametric Analysis Tool (PAT)

  • Select a baseline model to serve as the starting point for a parametric analysis
  • Drag in Measures and set their input values
  • Select combinations of Measures to run
  • Run the simulations locally or on the cloud
  • View a high-level comparison of the simulation results or dig into the detailed reports