Version 0.23
It is GeoPraxis' intention to support and encourage use of the Green Building XML library by anyone who can make good use of it to further interoperability in building related electronic commerce and environmental analyses.
This includes copying, modifying and distributing the Green Building XML Schema.
However, this must be done in accordance with the copyright statement below.
Copyright Statement
GeoPraxis, Inc. hereby grants to all users of the Green Building XML schema (gbXML) (the "Specification"), a perpetual, nonexclusive, royalty-free, world-wide right and license under any GeoPraxis, Inc. copyrights in the Specification to use, publish, copy, modify and distribute the Specification.
GeoPraxis further agrees to grant to users a royalty-free license under applicable GeoPraxis intellectual property rights to implement and use the gbXML tags, schema, and stylesheet guidelines included in the Specification for the purpose of creating computer programs that adhere to such guidelines.
One condition of this license shall be the licensee's agreement not to assert intellectual property rights against GeoPraxis, Inc. and other companies for implementation of the Specification.
GeoPraxis expressly disclaims any and all warranties regarding this Specification, including the warranty that this Specification or implementations thereof do not violate the rights of others.
These Specifications are provided "as is" without expressed or implied warranty.
If you publish, copy or distribute these specifications then this copyright notice must be attached. If you modify these specifications, then the following statement must be included in your specification:
'Parts of this specification are based on the GeoPraxis Green Building XML schema, version 1.0 (Copyright 2000 GeoPraxis, Inc.).
See http://www.idea-server.com/gbxml.htm for more details.'
Analysis engine used
SI or English units. True means that SI units are used throughout. False indicates English Inch-Pound units are used.
This attribute is intended to reduce the processing required. Units are still required for each value throughout, and will be used in case of inconsistancy.
The Campus element should be used as the base for all physical objects. On a campus, place one or more buildings.
ID for the weather data used for a heating design day
ID for the weather data used for a cooling design day
Height above sea level
Allows for including daylight savings time
Alternative energy source
Plants, trees, etc. on a campus
Refers to a building-level surface.
Public transportation
Geometry data in X3D format. All data is global, with the assumption that positive X is East, positive Y is North, and positive Z is up.
If geometry is to be precise, use Description element to define the origin (Flagpole at center of campus, North-east corner of building, etc.).
Otherwise the axis is an arbitrary point.
Set of 3-D faces
Comma-separated list describing the order that vertices are defined in a set of faces. A -1 denotes the end of a face definition. Each list item references a vertex in "point", starting with 0 and ending with N-1, where N is the number of vertices.
A list of vertices. The x, y, and z coordinates of each vertex is separated by a space, and each vertex is separated by a comma. Surfaces and openings contain only one face.
Defines the outward normal of a surface.
A space represents a volume enclosed by surfaces.
ID of the schedule for lights contained in this space
ID for schedule of equipment use
ID for schedule of people in this space
ID used by a CAD program to uniquely identify this object
Flow of air through building envelope
Leakage value obtained from blower door test.
Occupancy of the space
Amount of heat added to the space by people
Amount of power used by lighting in a given area
Amount of power used by equipment in a given area
ID of a second space that this surface touches (if an interior wall)
Identifier pointing to a construction
ID used by a CAD program to uniquely identify this object
ID for the schedule of transmittance of a shading surface
Transmittance of shading surface
Specifies whether this surface shades other surfaces
Identifier pointing to a construction
ID indicating the type of frame used
ID indicating the type of blinds used
ID used by a CAD program to uniquely identify this object
Distance from outside surface of window to outside surface of wall
Natural ventilation does not occur above this temperature.
Natural ventilation does not occur below this temperature.
Occupancy dependence of natural ventilation. If true, then natural ventalation only occurs when people are present.
Type of ballast used
Type of lamp used
Type of luminaire used
The coefficient of utilization is the ratio of luminous flux on a workplane to the luminous flux emitted by the lamps alone.
Room cavity ratio is a measure of the room cavity proportions.
ID for a resource meter
ConstructionType can be used to organize types of constructions
A Construction is a combination of layers, such as a wall or a roof
Use this attribute to reference objects in the DOE2 library
Overall conductance
Absorptance of the outside surface
Roughness of the outside surface
Reflectance of solar radiation
Percent of original building shell used in renovation
A Layer is a combination of one of more materials
Thermal resistance of the internal air film in a layer
MaterialType can be used to organize types of materials
This is an X3D element to map a texture to this material.
From X3D specification:
The ImageTexture node defines a texture map by specifying an image file and general parameters for mapping to geometry.
Texture maps are defined in a 2D coordinate system (s, t) that ranges from [0.0, 1.0] in both directions.
The bottom edge of the image corresponds to the S-axis of the texture map, and left edge of the image corresponds to the T-axis of the texture map.
The lower-left pixel of the image corresponds to s=0, t=0, and the top-right pixel of the image corresponds to s=1, t=1.
Specifies location of the image.
From X3D specification:
The texture is read from the URL specified by the url field.
When the url field contains no values, texturing is disabled.
Browsers shall support the JPEG and PNG image file formats.
In addition, browsers may support other image formats (e.g. CGM) which can be rendered into a 2D image.
Support for the GIF format is also recommended (including transparency).
From X3D specification:
If repeatS is TRUE, the texture map is repeated outside the [0.0, 1.0] texture coordinate range in the S direction so that it fills the shape.
If repeatS is FALSE, the texture coordinates are clamped in the S direction to lie within the [0.0, 1.0] range.
From X3D specification:
If repeatT is TRUE, the texture map is repeated outside the [0.0, 1.0] texture coordinate range in the T direction so that it fills the shape.
If repeatT is FALSE, the texture coordinates are clamped in the T direction to lie within the [0.0, 1.0] range.
Resistance of material
The rate water vapor is allowed through a surface
In metric units (SI), a perm is equal to the transfer of 1 nanogram of water per square metre of material per second under a pressure difference of 1 pascal. In imperial units, a perm is equal to the transfer of 1 grain (0.002285 oz.) of water per square foot of material per hour under a pressure difference of 1 inch of mercury (1.134 ft. of water).
One WindowType should be created for each type of window.
Create a Blind, Frame, and Cost for each OpeningType, and then add as many Glaze and Gaps as exist in the window.
Place these Glaze and Gap elements in order from outside to inside.
For instance, a two pane window will have Glaze Gap Glaze, where the first Glaze represents the outside surface.
Shading coefficient
Solar heat gain coefficient
Space between window panes
Properties of one layer of a window
Infra-red emmisivity
Set of schedules making up the year being modeled
Month and day year scedule begins
Month and day year schedule ends
Value for one block of time. Divides a day evenly into number of ScheduleValue elements defined in DaySchedule.
Example: If 12 ScheduleValue elements are defined, each will represent two hours
ID of heating schedule
Design temperature for cooling
Outside air schedule ID
ID of the fan schedule for this zone
Outside air flow per area
Outside air flow per person
Design temperature for heating
Design temperature for cooling
The AirLoop element represents the equipment serving one path of air
A piece of equipment serving an air-loop.
This is generalized to be able to contain any type of air loop equipment.
ID used by a CAD program to uniquely identify this object
Temperature
Maximum consumption of energy (power input)
ID for a resource meter
COP = Coefficient of Performance, EER = Energy Efficiency Ratio, SEER = Seasonal Efficiency Ratio, AFUE = Annual Fuel Usage Efficiency, Et = Thermal Efficiency, HSPF = Heating Seasonal Performance Factor, Eff = Efficiency
Used to represent part load performance
The PointData element allows for graph or tabular information to be entered.
The data type and units of the x and y axis are defined with the XAxis and YAxis elements.
The Equation element allows data for n-dimensional algebraic data to be entered.
The Expression element should contain an indepentant variable followed by an = sign and an equation containing dependant variables.
The independant and dependant variables are then defined by their respective tags.
The only mathmatical operations allowed are ^ (power), + (addition), - (subtraction), / (division), and * (multiplication).
Example: z=x+2*y^2 would have an IndependantVariable with a name = z, and two DependantVariables with names of x and y.
Descriptions would be included for each variable, along with unit and dataType information identifying the variable and its role.
This includes blowdown (draining a cooling tower to clean), drift (water loss from water sprayed), and evaporation in cooling towers.
The HydronicLoop element represents the equipment serving one path of water, or other liquid
A piece of equipment serving a hydronic loop (most commonly a water loop).
This is generalized to be able to contain any type of hydronic loop equipment.
ID used by a CAD program to uniquely identify this object
Interior equipment.
This is generalized to be able to contain any type of internal equipment.
ID used by a CAD program to uniquely identify this object
ID pointing to a hydronic loop
ID pointing to an air loop
Electric load
Waste water heat recovery efficiency
ID pointing to an air loop
ID pointing to a hydronic loop
Amount of water used for water using equipment per cycle of operation.
Number of operation cycles per week.
Heating degree days. HDD is calculated as the number of degrees a mean daily temperature is below a value (specified as the Temperature element), for each day.
For example, if the mean temperature in a region drops to 64 degrees for four days during a year, the rest of the time staying above 65, and the Temperature element is set at 65, then HDD = 4.
Cooling degree days. CDD is calculated as the number of degrees a mean daily temperature is above a value (specified as the Temperature element), for each day.
For example, if the mean temperature in a region rises to 77 degrees for three days during a year, the rest of the time staying below 75, and the Temperature element is set at 75, then CDD = 6.
Cooling degree day value
Cooling design day dry bulb temperature
Cooling design day hour of high temperature
Cooling design day wet bulb temperature
Cooling design day dry bulb temperature range
Cooling design day hour of low temperature
Cooling design day atmospheric pressure
Cooling design day wind speed
Cooing design day wind direction
Cooling design day sky clearness
Flag for rain on the cooling design day. 0=no rain, 1=rain
Flag for snow on the cooling design day. 0=not snowing, 1=snowing
Month the cooling design day lands on. 1=Jan, 12=Dec
Day of the month the cooling design day lands on
Flag for daylight savings on the cooling design day
Ground temperature on the cooling design day
Heating design day dry bulb temperature
Heating design day hour of high temperature
Heating design day wet bulb temperature
Heating design day dry bulb temperature range
Heating design day hour of low temperature
Heating design day atmospheric pressure
Heating design day wind speed
Heating design day wind direction
Heating design day sky clearness
Heating design day rain flag. 0=no rain, 1=rain
Heating design day snow flag. 0=not snowing, 1=snowing
Month that the heating design day occurs on. 1=Jan, 12=Dec
Day of the month that the heating design day occurs on
Flag for daylight savings for the heating design day
Ground temperature for the heating design day
Monthly ground temperatures, 12 values
Description of a resource measurement
Minimum flow
Difference in pressure
Difference in temperature
Indicates which object or objects the results apply to, if any
ID used by a CAD program to uniquely identify this object
Time or period that results represent. Example: if timeType = Month and Time = 1 the Value would be for the month of January or if timeType = Hour and Time = 324 the Value would be for January 14 at noon.
ID for a resource meter
ID for operation schedules
Year of simulation to use
ID for a resource meter
ID pointing at an interior equipment object
Identifier pointing at a light object
ID identifying a layer in this construction. Multiple layers in Constructions are in order from outside to inside.
ID identifying a material in this layer. Multiple materials in layers are in order from outside to inside.
ID used by a CAD program to reference its internal materials library
ID pointing to a hydronic loop
ID pointing to an air loop
ID indicating the type of glaze used
ID for a gap between window panes
External equipment.
This is generalized to be able to contain any type of external equipment.
ID used by a CAD program to uniquely identify this object
ID pointing to a hydronic loop
ID pointing to an air loop
Longitude is measured from Greenwich, England, east being positive
Latitude is measured from the equator, north being positive
the ratio of the total amount of void space in a material (due to poses, small channels, and so on) to the bulk volume occupied by the material.
Density as a function of temperature
Conductivity as a function of temperature
Viscosity as a function of temperature
Prandtl number as a function of temperature
We have left the UtilityRate element open to allow for use with billing schemas.