Summary
This proposal suggests extending the dotbim format with a universal metadata layer that supports:
• Bill of Quantities generation
• installation sequencing and duration
• construction planning
• building physics analysis
• equipment and product simulation
The schema remains optional and lightweight, consistent with the design philosophy of the dotbim format.
All calculations remain external to the format.
The metadata only stores parameters required for construction workflows and simulations.
⸻
Universal Metadata Structure
The following metadata groups are proposed. All fields are optional and may be used depending on the workflow.
⸻
- Element Identification
ElementType
ElementCategory
Description
Examples:
Wall
Pipe
Duct
CableTray
Window
Foundation
Equipment
Machine
Appliance
Purpose:
Provide a simple semantic description of the geometry element.
⸻
- Product Information
Manufacturer
ProductType
Model
ProductReference
Purpose:
Link geometry elements to real construction products or equipment.
Examples:
heat pump
window system
pump
coffee machine
⸻
- BoQ Metadata
UniqueBoQCode
MeasurementUnit
QuantitySource
Purpose:
Link model elements with cost items in the Bill of Quantities.
Examples:
concrete wall → cubic meters
plaster → square meters
pipe installation → meters
- Installation Metadata
InstallationSequence
InstallationZone
InstallationMethod
Purpose:
Describe installation order and grouping of construction tasks.
Example sequence:
10 – excavation
20 – foundations
30 – structural walls
40 – roof structure
50 – installations
60 – finishing works
The term installations includes all building services such as:
• mechanical systems
• electrical systems
• plumbing
• drainage
• technical equipment
⸻
- Installation Duration
InstallationHoursPerUnit
InstallationHoursPerMeter
InstallationHoursPerSquareMeter
InstallationHoursPerCubicMeter
Purpose:
Allow estimation of labor effort and construction duration.
⸻
- Construction Rule Metadata
Some works are derived from rules rather than explicit geometry.
Suggested fields:
InstallationType
SupportsPerMeter
SupportPerUnit
TrenchWidth
TrenchDepth
Purpose:
Allow software to derive additional work quantities such as:
• excavation
• pipe supports
• cable tray supports
• equipment mounting
- Thermal Properties
ThermalConductivity
ThermalResistance
UValue
SpecificHeatCapacity
Purpose:
Support simplified thermal and energy simulations.
Examples:
external wall insulation
window performance
equipment heat losses
⸻
- Acoustic Properties
SoundReductionIndex
AbsorptionCoefficient
ImpactSoundReduction
Equipment noise properties:
SoundPowerLevel
SoundPressureLevel
Purpose:
Allow evaluation of acoustic performance and noise generation.
Examples:
outdoor equipment
machinery
building envelope elements
⸻
- Daylight and Optical Properties
Applicable to transparent elements such as windows and glazing.
VisibleLightTransmittance
SolarHeatGainCoefficient
GlassUValue
FrameRatio
Purpose:
Enable daylight analysis and solar gain estimation.
⸻
- Electrical Properties
ElectricalPower
Voltage
Current
Efficiency
Purpose:
Describe electrical loads and energy consumption of equipment.
Examples:
heat pumps
pumps
lighting
appliances
⸻
- Fluid Flow Parameters
AirFlowRate
WaterFlowRate
PressureDrop
Purpose:
Describe flow characteristics for installation systems.
Examples:
air systems
water systems
process equipment
⸻
- Mechanical Properties
Mass
Density
OperatingTemperature
OperatingPressure
Purpose:
Support mechanical simulations and product engineering.
⸻
Example – Window Element
Metadata may include:
ElementType = Window
Manufacturer = Velux
VisibleLightTransmittance = 0.70
SolarHeatGainCoefficient = 0.45
GlassUValue = 1.1
InstallationSequence = 60
InstallationHoursPerUnit = 1.5
Software can estimate daylight penetration and installation effort.
⸻
Example – Underground Pipe
Metadata may include:
ElementType = Pipe
InstallationType = Underground
TrenchWidth = 0.30
TrenchDepth = 0.80
UniqueBoQCode = PIPE-UG-01
InstallationHoursPerMeter = 0.4
Software may derive excavation quantities and installation duration.
⸻
Example – Equipment Element
Metadata may include:
ElementType = Equipment
Manufacturer = Daikin
ElectricalPower = 1.8 kW
SoundPowerLevel = 65 dB
InstallationSequence = 120
InstallationHoursPerUnit = 2
Software can estimate energy consumption, acoustic impact, and installation scheduling.
⸻
Design Principles
The dotbim format remains:
• lightweight
• JSON based
• geometry focused
The metadata layer enables construction and simulation workflows without increasing schema complexity.
All calculations remain external to the format.
⸻
Benefits
A universal metadata layer allows dotbim models to support:
• cost estimation
• installation planning
• building physics simulations
• equipment performance analysis
• product engineering workflows
while preserving the simplicity and flexibility of the dotbim format.
Summary
This proposal suggests extending the dotbim format with a universal metadata layer that supports:
• Bill of Quantities generation
• installation sequencing and duration
• construction planning
• building physics analysis
• equipment and product simulation
The schema remains optional and lightweight, consistent with the design philosophy of the dotbim format.
All calculations remain external to the format.
The metadata only stores parameters required for construction workflows and simulations.
⸻
Universal Metadata Structure
The following metadata groups are proposed. All fields are optional and may be used depending on the workflow.
⸻
ElementType
ElementCategory
Description
Examples:
Wall
Pipe
Duct
CableTray
Window
Foundation
Equipment
Machine
Appliance
Purpose:
Provide a simple semantic description of the geometry element.
⸻
Manufacturer
ProductType
Model
ProductReference
Purpose:
Link geometry elements to real construction products or equipment.
Examples:
heat pump
window system
pump
coffee machine
⸻
UniqueBoQCode
MeasurementUnit
QuantitySource
Purpose:
Link model elements with cost items in the Bill of Quantities.
Examples:
concrete wall → cubic meters
plaster → square meters
pipe installation → meters
InstallationSequence
InstallationZone
InstallationMethod
Purpose:
Describe installation order and grouping of construction tasks.
Example sequence:
10 – excavation
20 – foundations
30 – structural walls
40 – roof structure
50 – installations
60 – finishing works
The term installations includes all building services such as:
• mechanical systems
• electrical systems
• plumbing
• drainage
• technical equipment
⸻
InstallationHoursPerUnit
InstallationHoursPerMeter
InstallationHoursPerSquareMeter
InstallationHoursPerCubicMeter
Purpose:
Allow estimation of labor effort and construction duration.
⸻
Some works are derived from rules rather than explicit geometry.
Suggested fields:
InstallationType
SupportsPerMeter
SupportPerUnit
TrenchWidth
TrenchDepth
Purpose:
Allow software to derive additional work quantities such as:
• excavation
• pipe supports
• cable tray supports
• equipment mounting
ThermalConductivity
ThermalResistance
UValue
SpecificHeatCapacity
Purpose:
Support simplified thermal and energy simulations.
Examples:
external wall insulation
window performance
equipment heat losses
⸻
SoundReductionIndex
AbsorptionCoefficient
ImpactSoundReduction
Equipment noise properties:
SoundPowerLevel
SoundPressureLevel
Purpose:
Allow evaluation of acoustic performance and noise generation.
Examples:
outdoor equipment
machinery
building envelope elements
⸻
Applicable to transparent elements such as windows and glazing.
VisibleLightTransmittance
SolarHeatGainCoefficient
GlassUValue
FrameRatio
Purpose:
Enable daylight analysis and solar gain estimation.
⸻
ElectricalPower
Voltage
Current
Efficiency
Purpose:
Describe electrical loads and energy consumption of equipment.
Examples:
heat pumps
pumps
lighting
appliances
⸻
AirFlowRate
WaterFlowRate
PressureDrop
Purpose:
Describe flow characteristics for installation systems.
Examples:
air systems
water systems
process equipment
⸻
Mass
Density
OperatingTemperature
OperatingPressure
Purpose:
Support mechanical simulations and product engineering.
⸻
Example – Window Element
Metadata may include:
ElementType = Window
Manufacturer = Velux
VisibleLightTransmittance = 0.70
SolarHeatGainCoefficient = 0.45
GlassUValue = 1.1
InstallationSequence = 60
InstallationHoursPerUnit = 1.5
Software can estimate daylight penetration and installation effort.
⸻
Example – Underground Pipe
Metadata may include:
ElementType = Pipe
InstallationType = Underground
TrenchWidth = 0.30
TrenchDepth = 0.80
UniqueBoQCode = PIPE-UG-01
InstallationHoursPerMeter = 0.4
Software may derive excavation quantities and installation duration.
⸻
Example – Equipment Element
Metadata may include:
ElementType = Equipment
Manufacturer = Daikin
ElectricalPower = 1.8 kW
SoundPowerLevel = 65 dB
InstallationSequence = 120
InstallationHoursPerUnit = 2
Software can estimate energy consumption, acoustic impact, and installation scheduling.
⸻
Design Principles
The dotbim format remains:
• lightweight
• JSON based
• geometry focused
The metadata layer enables construction and simulation workflows without increasing schema complexity.
All calculations remain external to the format.
⸻
Benefits
A universal metadata layer allows dotbim models to support:
• cost estimation
• installation planning
• building physics simulations
• equipment performance analysis
• product engineering workflows
while preserving the simplicity and flexibility of the dotbim format.