Model Parameter: Precast Concrete Facade System & External Thermal Insulation Composite System (ETICS)

  1. Precast Concrete Facade System
    1. Constraints
      • Module Width [m]
        The module width of the precast concrete façade system is defined as a fixed constraint within the model. This parameter governs the modularity of the façade and directly influences cost efficiency, manufacturing standardization, and engineering feasibility. By fixing the module width, the model ensures efficient prefabrication, rapid assembly, and consistent reproducibility across different design configurations.
    2. Design Variables
      • Insulation Dimension and Material, Window Glazing and Construction (U-Values) [W/m2⋅K]
        Insulation thickness and material, as well as window glazing type and construction, directly influence the overall thermal performance of the building envelope. Lower U-values indicate reduced heat transfer through the façade, resulting in lower heat losses in heating-dominated periods and reduced heat gains during cooling-dominated periods. By varying these parameters within the model, a combined U-value for the façade is calculated, providing direct insight into the energy efficiency of each design configuration.
        • Typical U-Value of Windows:
          0.70-0.90: High-performance triple glazing
          1.00-1.30: Typical energy efficient glazing
          1.40-1.60: Standard or lower-performance glazing
        • Typical U-Value of Walls1:
          0.12-0.18: High-performance envelope (near passive house or advanced new construction)
          0.20-0.28: Typical high efficiency new construction
          0.30-0.35: Standard or conservative envelope design
      • Window-to-Wall Ratio (WWR)
        The window-to-wall ratio (WWR) is varied within the precast façade module over a range of 10% to 60%. These bounds represent minimum and maximum realistic glazing proportions, governed by geometric feasibility and engineering constraints2. Lower WWR values may fail to satisfy daylight requirements, while higher values can compromise structural integrity, privacy, and thermal performance. Varying the WWR within this range enables the assessment of trade-offs between operational energy efficiency and occupant comfort.
  2. External Thermal Insulation Composite System (ETICS)
    The extent and configuration of the ETICS are inherently linked to the façade design and are therefore directly dependent on the variables defined within the precast concrete façade system. As a result, the insulation-related constraints and design variables established for the façade, such as insulation thickness, material, and coverage, also govern the ETICS configuration. In the model, these parameters collectively determine the resulting overall U-value of the wall, influencing the building’s thermal performance.
Model Parameter: Metro StationModel Parameter: Tunnel
Model Parameter: Station BoxModel Parameter: Stormwater Vault
Integrated Parametric ModelResults Analysis: Design Exploration

Reference:

  1. Alimohammadisagvand, B. (2018). Influence of demand response actions on thermal comfort and electricity cost for residential houses. Aaltodoc (Aalto University). https://aaltodoc.aalto.fi/handle/123456789/33143 ↩︎
  2. Precast/Prestressed Concrete Institute. (2015). Precast-Prestressed Concrete Parking Structure: Recommended Practice for Design and Construction (3rd ed.). PCI. https://www.pci.org/PCI_Docs/PCI_Manuals_PDFs/Promotional/Precast-Prestressed-Concrete-Parking-Structure-Recommended-Practice-for-Design-and-Construction-3rd-Edition-MNL-129-15.pdf
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