All attic spaces in the building.
Array of Attic objects that represent the ceiling/roof components being conditioned/unconditioned attic spaces.
Used to calculate:
For F280: Processed as thermal boundaries in energy modeling:
For EnerGuide and HOT2000:
All basement structures in the building.
Array of Basement objects that define below-grade spaces with their geometries, insulation properties, and thermal characteristics.
Used to calculate:
For F280: Critical for foundation heat loss calculation:
For EnerGuide:
Similar to the attic but used for vaulted ceilings. The construction of a cathedral ceiling is similar to a deck but at an angle. It also contains an air volume under its slopped roof that needs to be factored in the heat loss calculations.
All crawlspace structures in the building.
Array of CrawlSpace objects defining shallow foundation spaces with various ventilation types (heated, open, vented).
Used to calculate:
For F280: Processed as special thermal boundaries:
For EnerGuide specific properties:
Similar to the attics but used for flat roofs and balcony spaces directly above the heated space.
All mechanical and energy systems in the building.
Contains detailed specifications for HVAC, water heating, ventilation, and renewable energy systems that affect building energy performance.
Used to calculate:
For F280: Critical for heat loss/gain calculations:
For EnerGuide: Extensively used for the rating:
All floor structures exposed to exterior/unheated conditions:
Array of ExposedFloor objects representing floors over unconditioned spaces (except for crawl spaces) or outdoor air (such as cantilevered floors or floors over garages).
It represents a boundary with heat generally flowing downward.
For F280: Included in thermal boundary calculations:
For EnerGuide:
All slab-on-grade foundations in the building.
Array of SOG objects that define concrete slabs directly on grade (ground), with their insulation properties and perimeter characteristics.
Used to calculate:
For F280: Treated as specialized foundation boundaries:
For EnerGuide: Exported to HOT2000 with foundation-specific configuration:
General characteristics of the interior space
Air changes per hour at 50 Pa pressure difference (airtightness measurement).
Quantifies the building envelope leakage rate. Typical values range from 1-3 ACH for airtight construction, 3-8 for average buildings, and >8 for leaky construction. Lower values indicate better airtightness.
Used in conjunction with the building volume to determine the uncontrolled air leakage.
For F280: Converted to equivalent leakage area (ELA) and used to determine heating and cooling air changes per hour in normal operating conditions. Predefined coefficient sets exist for values 1.5, 3.57, 4.55, and 10.35. Other values get interpolated.
For EnerGuide: Impacts the natural air infiltration calculations in the simulation.
Optionalbaseline_ach?: number | ""Optional baseline airtightness value to calculate renovation costs
Optionaloperation?: "ref" | "f280"Operating mode for simulation.
'ref': Indicates this is a reference building. Reference buildings bypass certain validation checks particularly around perimeter-to-area ratios.
'f280': Indicates this house is built for F280 compliance calculations. Seeds with this mode also skip certain geometry validations that would normally apply to EnerGuide building models.
This property affects validation rules but does not directly impact calculations in the Seed and the helpers. It primarily serves as a flag to identify the intended use of the house model.
For EnerGuide: Leave empty for a normal operation. Specifying a value does not negatively impact EnerGuide calculations. Not directly used in HOT2000 export, but affects validation that may be performed before export.
Optionalrooms?: Room[]Array of rooms contained within the building, defining spaces and their characteristics.
Used in the total_heated_area calculation when an explicit
total heated area isn't provided. The system sums up the heated_area_m2 value of
each room to determine the building's total heated area.
For F280: Extensively used in the energy modeling system to:
When not provided, the system falls back to doing a block load calculation.
For EnerGuide: Not directly used in HOT2000 exports, which use hardcoded default values and a whole-building model.
Optionalshape?: Position[][]Optional geometric representation of the building footprint as a GeoJSON Polygon coordinate array. Consists of [longitude, latitude] points defining the building's perimeter.
Used in to determine wall orientations and for distributing windows appropriately around the building when the windows are not explicitly defined in virtual rating.
If not provided, a default rectangular shape is created based on the building's latitude and longitude coordinates from the project information.
For F280: Not directly used in energy modeling calculations.
For EnerGuide: Not utilized directly in the inputs.
Year of construction of the building.
The year property is documented but not directly used in calculations. Nonetheless, for low-fidelity simulations such as those done in virtual rating, the year built can help Properate fill-in the blanks.
All exterior and unheated-facing walls in the building.
The array of Wall objects that defines the building's thermal envelope and structure. Each wall contains information about its dimensions, orientation, thermal properties, and attached components (windows/doors).
Used extensively to calculate:
For F280: Used to define thermal boundaries for energy modeling:
For EnerGuide and HOT2000:
The core data structure representing a house in version 16 of the Seed schema. Contains all building components, equipment, and general characteristics.