An Open Toolchain for Generating Modelica Code from Building Information Models

Abstract

Building Performance Simulation (BPS) is a key element in the design of energy efficient buildings, and there is increasing interest in using the Modelica modelling language for BPS. The IEA-EBC coordinates development of BPS in Modelica in the project "Computational Tools for Building and Community Energy Systems" (Annex 60). However, developing BPS models and collecting required input data are time-consuming and error-prone processes. Reusing existing Building Information Models (BIM) as basis for Building Performance Simulation (BPS) has the potential to make BPS model development and subsequent simulation easier, faster and more reliable. Activity 1.3 of the Annex 60 project is working on an open-source toolchain that can semi-automatically generate code for BPS Modelica models from a BIM data source. Parts of that toolchain are discussed in this paper.

An IFC data preparation workflow for building energy performance simulation

“…To define and retrieve such information, the BIM designer must activate the thermal properties population for each material through the "Thermal" tab. Most IFC-to-BEPS methods currently use construction and material thermal properties of building elements from fixed predefined libraries (Thorade et al 2015. However, as mentioned above, this information can be explicitly prescribed in the Revit TM model, and can also be represented in IFC (e.g.…”

“…Building Information Models (BIM) are information-rich repositories that could be used to streamline and expedite the collection of such information. Hence, recent research studies focus on BIM-based BEPS models generation (Andriamamonjy et al 2018, Thorade et al 2015. BIM is an object-oriented digital representation of a building, which also can capture part of the information required for generating a BEPS input data file.…”

BIM2Modelica - An open source toolchain for generating and simulating thermal multi-zone building models by using structured data from BIM models

“…In the next step of the toolchain, the Modelica building models are generated using the information stored in the building data model. For this purpose, the Python based module CoTeTo (Code Templating Tool) is used, which was developed in the EnEff-BIM project (see Thorade et al, 2015). BIM2Modelica -An open source toolchain for generating and simulating thermal multi-zone building models by using structured data from BIM models CoTeTo can be flexibly configured with pluggable input, filter, and output components which support the single steps of data acquisition, preprocessing and code generation using a template system.…”

“…For this reason, different research activities during the last years have been focused on the automatic generation of Modelica building models using IFC building models as the input (e.g. Thorade et al, 2015 andReynders et al, 2017).…”

“…The toolchain described in Thorade et al (2015) is based on the SimModel data model (O'Donnell et al 2011). This data structure is able to store all relevant information for building energy simulation (the building construction and the related HVAC system), which is present in the BIM model itself (the IFC file) and which is optionally added by further data sources (e.g.…”