Extensions¶

Extensions add computed properties to generated models. They are mixed into the model classes at code generation time, so editors auto-complete them like ordinary fields.

Geometry¶

Surface objects gain geometry computed from their vertices with Newell's method:

surface = idf.get('BuildingSurface:Detailed', 'Wall1')

surface.area                # 30.0, in m²
surface.normal              # (0.0, -1.0, 0.0), outward unit normal
surface.centroid            # (5.0, 0.0, 1.5)
surface.tilt                # 90.0, degrees from horizontal
surface.azimuth             # 180.0, degrees clockwise from north
surface.perimeter
surface.bounding_box
surface.is_convex
surface.vertices_as_tuples  # [(0, 0, 3), (0, 0, 0), (10, 0, 0), (10, 0, 3)]

Supported types: BuildingSurface:Detailed, FenestrationSurface:Detailed, Floor:Detailed, RoofCeiling:Detailed, Wall:Detailed, Shading:Building:Detailed, Shading:Site:Detailed and Shading:Zone:Detailed.

Constructions¶

Construction gains layers, is_window_construction and is_opaque_construction; see Navigating references.

Writing a plugin¶

An extension is a sub-package of idfpy.ext that exposes MIXIN_MAP, mapping generated class names to mixin classes:

# idfpy/ext/thermal/__init__.py
from .mixins import ThermalPropertyMixin

MIXIN_MAP: dict[str, type] = {
    'BuildingSurfaceDetailed': ThermalPropertyMixin,
}

# idfpy/ext/thermal/mixins.py
class ThermalPropertyMixin:
    @property
    def u_value(self) -> float:
        """U-value of the surface construction, in W/(m²·K)."""
        ...

Regenerate the models so the code generator injects the mixin:

idfpy codegen --schema Energy+.schema.epJSON --output idfpy/models