Starter Geometry in IESVE 2018 - ASHRAE Standard 209 and LEED Integrative Process

By Liam Buckley on Monday 11 June 2018

Many IESVE users have been excited about ASHRAE’s introduction of Standard 209-2018: Energy Simulation Aided Design for Buildings Except Low-Rise Residential Buildings [Ref: ASHRAE.org], as it describes a methodology to apply building energy modeling to the building design process. Compliance must be shown for two of the following design cycles:

  1. Simple Box Modeling
  2. Conceptual Design Modeling
  3. Load Reduction Modeling (Mandatory)
  4. HVAC System Selection Modeling
  5. Design Refinement
  6. Design Integration and Optimization
  7. Energy Simulation Aided Value Engineering 

Modeling Cycle # 1 for Simple Box Modeling is required before the building geometry and orientation have been set and the analyses must be completed before or during the energy charrette. Sensitivity analysis is to include the geometry of the building, orientation, glazing fraction (window-to-wall ratio), and thermal performance of the envelope and structure.

The obvious question:  How do we perform simulation-aided analysis when the geometry has not been set?  Luckily, ASHRAE 209-2018 has provided guidance for such situations when the rough building form has not been otherwise prescribed and to follow the ​​recommended Commercial Reference Building Models guidance as detailed below. 

All of these Commercial Reference Building Models are readily available in the new Start Page of IESVE-2018 (See ‘New Project’), along with convenience of assigning the user’s most regularly used weather data (See ‘Pinned Location & Weather’ on the Start Page). 

So what to do next?

Once that Starter Geometry has been imported, it is important to assign some of the prototypical ASHRAE 90.1 thermal template data, so IESVE users should choose one of the 90.1 options: 2004, 2007, 2010 or 2013. After that selection, it is up to the user how to perform analysis. One suggestion would be to use the Parametric Batch Processor.


LEED’s Integrative Process Credit

There is some striking similarities in LEED’s Integrative Process credit [Ref: USGBC.org] for energy-related systems, which also calls for “simple box” energy modeling analysis, before schematic design is complete. This analysis is to explore how to reduce energy loads in the building, assess similar metrics as referred to by ASHRAE 209-2018, and some other metrics such as lighting levels and thermal comfort ranges. In the LEEDv4 Navigator in IESVE-2018, additional functionality and video support is provided.

For those IESVE Users who are curious about what exactly that starter geometry is for, now you know!