Import Factories
Import factories are pipelines that are used to enrich the city. This can include assigning construction materials to a building, designating a building’s function (e.g. commercial, educational, residential, etc.), and more. Currently, the following Import Factories are available:
Geometry Factory
The Geometry Factory is the entry point to the City Model Structure. Upon calling the Geometry Factory, the city is created.
The following properties are read from the user provided dataset
Property |
Description |
|---|---|
Aliases Field |
Name of the field for the building aliases. These can be used to search for building in a city. Examples may include a building ID, street address, business name, etc. |
Height Field |
Name of the field for the height of the building in meters. |
Year of Construction Field |
Name of the field for the year the building was constructed. |
Usages Field |
Name of the field for the usages of building. |
Storey Height Field |
Name of the field from user input dataset for the height of each storey. The default is assumed to be 3.5 meters. |
Building Footprint |
A set of latitude, longitude coordinates which describe the footprint of the building. |
Once the user provided data has been read and processed, the Geometry Factory enriches the geometrical structure of the buildings. After reading the footprint of the building, the height, and the storey height (defaults to 3.5 meters if not provided), this factory generates the surfaces (floors, walls, and ceilings) as well as the thermal zones.
A summarized list of properties are set or calculated by the Geometry Factory
Property |
Description |
|---|---|
Centroid |
A 3D coordinate in the EPSG:26911 Coordinate Reference System (CRS) representing the center of the building |
Floor Area |
The area of each floor of the building in square meters |
Upper Corner |
A 3D coordinate in the EPSG:26911 Coordinate Reference System (CRS) representing the upper left corner of the building |
Lower Corner |
A 3D coordinate in the EPSG:26911 Coordinate Reference System (CRS) representing the lower right corner of the building |
Surfaces |
The physical boundaries such as walls, floors, roofs, windows, and doors—that enclose spaces, separate zones, and influence a building’s performance and appearance. |
Volume |
Volume of the building in cubic meters |
Simplified Polyhedron |
A simplified polyhedron representing the 3D structure of the building |
Walls |
|
Grounds |
Internal Zones
Internal Zones refer to distinct areas within a building floor that is separated by internal walls and defined by its specific function or use.
Property |
Description |
|---|---|
Property 1 |
|
Property 2 |
Note
The Geometry Factory currently supports the following input data file formats: geojson, obj, and citygml
Construction Factory
Using construction archetypes, the Construction Factory enriches the physical properties of the building. This includes construction materials, windows, walls, insulation, etc.
The construction factory enriches the buildings with the following properties
Thermal Properties
Property |
Description |
|---|---|
Average Storey Height |
Average height for each story. This is either provided by the input dataset or by the function archetype |
Losses from Thermal Bridges |
|
Thermal Capacity |
|
Indirect Heated Ratio |
|
Infiltration Rate with Ventilation System On |
|
Infiltration Rate with Ventilation System Off |
|
Infiltration Rate Area with Ventilation System On |
|
Infiltration Rate Area with Ventilation System Off |
Constructions
Property |
Description |
|---|---|
Type |
Average height for each story. This is either provided by the input dataset or by the function archetype |
Name |
|
Window-to-Wall Ratio |
Layers
Property |
Description |
|---|---|
Thickness |
Thickness of the layer |
Material Name |
|
Insulation Thermal Resistance |
|
Density |
|
Conductivity |
|
Solar Absorptance |
|
Thermal Absorptance |
|
Visible Absorptance |
Windows
Property |
Description |
|---|---|
Name |
|
Frame Ratio |
|
g-Value |
|
u-Value |
Usage Factory
Using usage archetypes, the Usage Factory enriches the city with different properties and schedules depending on the usage of the building. The CITYhub supports multiple usages by splitting the volume proportionally depending on the user provided usages and their percentages.
Occupancies
Property |
Description |
|---|---|
Occupancy Density |
|
Sensible Radiative Internal Gain |
|
Latent Internal Gain |
|
Sensible Convective Internal Gain |
|
Occupancy Schedules |
Lightings
Property |
Description |
|---|---|
Lighting Density |
|
Convective Fraction |
|
Radiative Fraction |
|
Latent Fration |
|
Lighting Schedules |
Appliances
Property |
Description |
|---|---|
Appliance Density |
|
Convective Fraction |
|
Radiative Fraction |
|
Latent Fraction |
|
Appliance Schedules |
Thermal Controls
Property |
Description |
|---|---|
Cooling Set Point Schedules |
|
Heating Set Point Schedules |
|
HVAC Availability Schedules |
Domestic Hot Water
Property |
Description |
|---|---|
Peak Flow |
|
Service Temperature |
|
Domestic Hot Water Density |
|
Domestic Hot Water Schedules |
Weather Factory
The Weather Factory enriches the city with historical weather data based on the location of the city. The CITYhub dynamically downloads EnergyPlus Weather files from the EnergyPlus website using the location of the city. These weather values are later used during energy simulations to estimate the associated demands of a building depending on external temperatures.
Energy Systems Factory
The Energy Systems Factory is responsible for enriching the buildings with their corresponding energy system(s). These energy systems are then used by external simulation software to improve the accuracy of energy simulations. The following properties are set by the Energy Systems Factory:
Property |
Description |
|---|---|
Demand Types |
|
Generation Systems |
|
Distribution Systems |
Generation System
Property |
Description |
|---|---|
System Type |
Type of the generation system |
Fuel Type |
Type of fuel used by the generation system |
Source Types |
|
Electrical Efficiency |
|
Heating Efficiency |
|
Cooling Efficiency |
|
Energy Storage System |
Generic Storage System
Property |
Description |
|---|---|
Energy Type Stored |
Type of energy stored by the storage system |
Height |
|
Layers |
|
Storage Medium |
Distribution System
Property |
Description |
|---|---|
System Type |
Type of the distribution system |
Distribution Consumption Fix Flow |
|
Distribution Consumption Variable Flow |
|
Heat Losses |
|
Emission Systems |
CO2 Analysis Factory
The CO₂ Analysis Factory enriches buildings with their CO₂ emissions based on the full building lifecycle, including embodied, operational, and end-of-life emissions. This comprehensive approach allows for a holistic understanding of a building’s carbon footprint across its entire lifecycle.
Note
The CO2 Analysis Factory currently only supports Embodied CO2 and End-of-Life CO2. Operational CO2 can be calculated using the cerc-co2-emissions Python package.
Property |
Description |
|---|---|
Embodied CO2 |
Embodied emissions account for the carbon released during the extraction, manufacturing, and transportation of construction materials, as well as the construction process itself. |
Operational CO2 |
Operational emissions reflect the CO₂ produced during the building’s use phase, primarily from energy consumption for heating, cooling, lighting, and appliances. |
End-of-Life CO2 |
End-of-life emissions capture the carbon impacts associated with demolition, waste processing, material recovery, and disposal at the end of the building’s lifespan. |
Results Factory
The Results Factory enriches the city with data produced from external software. This includes
Energy Simulations (supports hourly, monthly, and yearly values)
Property |
Description |
|---|---|
Heating Demand |
The energy required to heat a building to a specific temperature |
Heating Consumption |
The energy actually used to heat a building to a specific temperature |
Heating Peak Load |
The maximum energy required to heat a building given the worst conditions |
Cooling Demand |
The energy required to cool a building to a specific temperature |
Cooling Consumption |
The energy actually used to cool a building to a specific temperature |
Cooling Peak Load |
The maximum energy required to cool a building given the worst conditions |
Domestic Hot Water Demand |
The energy required to provide hot water to building |
Domestic Hot Water Consumption |
The energy actually used to provide hot water to building |
Domestic Hot Water Peak Load |
The maximum energy required to provide hot water to a building given the worst conditions |
Electrical Appliances Demand |
The energy required to operate household appliances |
Electrical Appliances Peak Load |
The maximum energy required to operate household appliances assuming all appliances are running simultaneously |
Lighting Demand |
The energy required to operate lights of a building |
Lighting Peak Load |
The maximum energy required to operate household appliances assuming all lights are running simultaneously |
Distribution Systems Electrical Consumption |
|
Onsite Electrical Production |
|
Solar Panel (PV) Generation |
|
Solar Radiosity |
The amount of energy a building absorb by waves from the sun |