diff --git a/src/xeto/ph.attrs/base.xeto b/src/xeto/ph.attrs/base.xeto
index d3d1624..39e8a7f 100644
--- a/src/xeto/ph.attrs/base.xeto
+++ b/src/xeto/ph.attrs/base.xeto
@@ -37,3 +37,26 @@ TempAttr : NumberAttr <abstract> {
   val: Number <quantity:"temperature">
 }
 
+// Attribute with a number value with volumetric flow unit
+VolumetricFlowAttr : NumberAttr <abstract> {
+  flow
+  val: Number <quantity:"volumetricFlow">
+}
+
+// Attribute with a number value with power unit
+PowerAttr : NumberAttr <abstract> {
+  power
+  val: Number <quantity:"power">
+}
+
+// Attribute with a number value with energy unit
+EnergyAttr : NumberAttr <abstract> {
+  energy
+  val: Number <quantity:"energy">
+}
+
+// Attribute with a number value with pressure unit
+PressureAttr : NumberAttr <abstract> {
+  pressure
+  val: Number <quantity:"pressure">
+}
\ No newline at end of file
diff --git a/src/xeto/ph.attrs/flow.xeto b/src/xeto/ph.attrs/flow.xeto
new file mode 100644
index 0000000..074b86d
--- /dev/null
+++ b/src/xeto/ph.attrs/flow.xeto
@@ -0,0 +1,106 @@
+//
+// Copyright (c) 2025, Project-Haystack
+// Licensed under the Academic Free License version 3.0
+//
+// History:
+//   13 Dec 2025 Lincoln Harmer Creation
+//
+
+//  Air flow of the asset
+AirFlowAttr: VolumetricFlowAttr <abstract> { air }
+
+//////////////////////////////////////////////////////////////////////////
+// Design airflow attributes
+//////////////////////////////////////////////////////////////////////////
+
+//  Design air flow of the asset
+DesignAirFlowAttr: AirFlowAttr <abstract> { design }
+
+// Maximum design air flow of the asset
+MaxDesignAirFlowAttr: DesignAirFlowAttr <abstract> { max }
+
+// Discharge maximum design air flow of the asset
+DischargeMaxDesignAirFlowAttr: MaxDesignAirFlowAttr { discharge }
+
+// Cooling maximum design air flow of the asset
+CoolingDischargeMaxDesignAirFlowAttr: DischargeMaxDesignAirFlowAttr { cooling }
+
+// Heating maximum design air flow of the asset
+HeatingDischargeMaxDesignAirFlowAttr: DischargeMaxDesignAirFlowAttr { heating }
+
+// Outdoor maximum design air flow of the asset
+OutdoorMaxDesignAirFlowAttr: MaxDesignAirFlowAttr { outdoor }
+
+// Minimum design air flow of the asset
+MinDesignAirFlowAttr: DesignAirFlowAttr <abstract> { min }
+
+// Discharge minimum design air flow of the asset
+DischargeMinDesignAirFlowAttr: MinDesignAirFlowAttr { discharge }
+
+// Cooling discharge minimum design air flow of the asset
+CoolingDischargeMinDesignAirFlowAttr: DischargeMinDesignAirFlowAttr { cooling }
+
+// Heating discharge minimum design air flow of the asset
+HeatingDischargeMinDesignAirFlowAttr: DischargeMinDesignAirFlowAttr { heating }
+
+// Outdoor design minimum air flow of the asset
+OutdoorMinDesignAirFlowAttr: MinDesignAirFlowAttr { outdoor }
+
+//////////////////////////////////////////////////////////////////////////
+// Rated air flow attributes
+//////////////////////////////////////////////////////////////////////////
+
+// Rated air flow of the asset
+RatedAirFlowAttr: AirFlowAttr <abstract> { rated }
+
+// Maximum rated air flow of the asset
+MaxRatedAirFlowAttr: RatedAirFlowAttr <abstract> { max }
+
+// Discharge maximum rated air flow of the asset
+DischargeMaxRatedAirFlowAttr: MaxRatedAirFlowAttr { discharge }
+
+// Cooling maximum discharge rated discharge air flow of the asset
+CoolingDischargeMaxRatedAirFlowAttr: DischargeMaxRatedAirFlowAttr { cooling }
+
+// Heating maximum rated discharge air flow of the asset
+HeatingDischargeMaxRatedAirFlowAttr: DischargeMaxRatedAirFlowAttr { heating }
+
+// Outdoor maximum rated air flow of the asset
+OutdoorMaxRatedAirFlowAttr: MaxRatedAirFlowAttr { outdoor }
+
+// Minimum rated air flow of the asset
+MinRatedAirFlowAttr: RatedAirFlowAttr <abstract> { min }
+
+// Discharge minimum rated air flow of the asset
+DischargeMinRatedAirFlowAttr: MinRatedAirFlowAttr { discharge }
+
+//////////////////////////////////////////////////////////////////////////
+// Water flow Attributes
+//////////////////////////////////////////////////////////////////////////
+
+//  Water flow of the asset
+WaterFlowAttr: VolumetricFlowAttr <abstract> { water }
+
+//  Design water flow of the asset
+DesignWaterFlowAttr: WaterFlowAttr { design }
+
+//  Rated water flow of the asset
+RatedWaterFlowAttr: WaterFlowAttr { rated }
+
+//  Maximum design water flow of the asset
+MaxDesignWaterFlowAttr: DesignWaterFlowAttr { max }
+
+//  Chilled maximum design water flow of the asset
+ChilledMaxDesignWaterFlowAttr: MaxDesignWaterFlowAttr { chilled }
+
+//  Hot maximum design water flow of the asset
+HotMaxDesignWaterFlowAttr: MaxDesignWaterFlowAttr { hot }
+
+//  Minimum design water flow of the asset
+MinDesignWaterFlowAttr: DesignWaterFlowAttr { min }
+
+//  Maximum rated water flow of the asset
+MaxRatedWaterFlowAttr: RatedWaterFlowAttr { max }
+
+//  Minimum rated water flow of the asset
+MinRatedWaterFlowAttr: RatedWaterFlowAttr { min }
\ No newline at end of file
diff --git a/src/xeto/ph.attrs/power.xeto b/src/xeto/ph.attrs/power.xeto
new file mode 100644
index 0000000..0d40f13
--- /dev/null
+++ b/src/xeto/ph.attrs/power.xeto
@@ -0,0 +1,67 @@
+//
+// Copyright (c) 2025, Project-Haystack
+// Licensed under the Academic Free License version 3.0
+//
+// History:
+//   13 Dec 2025 Lincoln Harmer Creation
+//
+
+//////////////////////////////////////////////////////////////////////////
+// Capacity attributes
+//////////////////////////////////////////////////////////////////////////
+
+// Rated Capacity of the asset
+RatedCapacityAttr : PowerAttr <abstract> { rated, capacity }
+
+// Design Capacity of the asset
+DesignCapacityAttr : PowerAttr <abstract> { design, capacity }
+
+// Cooling rated capacity of the asset
+CoolingRatedCapacityAttr : RatedCapacityAttr { cooling }
+
+// Cooling design capacity of the asset
+CoolingDesignCapacityAttr : DesignCapacityAttr { cooling }
+
+// Heating rated capacity of the asset
+HeatingRatedCapacityAttr : RatedCapacityAttr { heating }
+
+// Heating design capacity of the asset
+HeatingDesignCapacityAttr : DesignCapacityAttr { heating }
+
+//////////////////////////////////////////////////////////////////////////
+// Fan and pump design power attributes
+//////////////////////////////////////////////////////////////////////////
+
+// Design motor power of the asset
+DesignMotorPowerAttr : PowerAttr <abstract> { design, motor }
+
+// Design fan motor power of the asset
+FanDesignMotorPowerAttr : DesignMotorPowerAttr <abstract> { fan }
+
+// Pump design motor power of the asset
+PumpDesignMotorPowerAttr : DesignMotorPowerAttr <abstract> { pump }
+
+// Discharge fan design motor power of the asset
+DischargeFanDesignMotorPowerAttr : FanDesignMotorPowerAttr { discharge }
+
+// Return fan design motor power of the asset
+ReturnFanDesignMotorPowerAttr : FanDesignMotorPowerAttr { return }
+
+//////////////////////////////////////////////////////////////////////////
+// Fan and pump rated power attributes
+//////////////////////////////////////////////////////////////////////////
+
+// Rated motor power of the asset
+RatedMotorPowerAttr : PowerAttr <abstract> { rated, motor }
+
+// Fan rated motor power of the asset
+FanRatedMotorPowerAttr : RatedMotorPowerAttr <abstract> { fan }
+
+// Pump rated motor power of the asset
+PumpRatedMotorPowerAttr : RatedMotorPowerAttr <abstract> { pump }
+
+// Discharge fan rated motor power of the asset
+DischargeFanRatedMotorPowerAttr : FanRatedMotorPowerAttr { discharge }
+
+// Return fan rated motor power of the asset
+ReturnFanRatedMotorPowerAttr : FanRatedMotorPowerAttr { return }
\ No newline at end of file
diff --git a/src/xeto/ph.attrs/pressure.xeto b/src/xeto/ph.attrs/pressure.xeto
new file mode 100644
index 0000000..1089b99
--- /dev/null
+++ b/src/xeto/ph.attrs/pressure.xeto
@@ -0,0 +1,33 @@
+//
+// Copyright (c) 2025, Project-Haystack
+// Licensed under the Academic Free License version 3.0
+//
+// History:
+//   12 May 2025 Lincoln Harmer Creation
+//
+
+//////////////////////////////////////////////////////////////////////////
+// Design pressure attributes
+//////////////////////////////////////////////////////////////////////////
+
+// Design pressure of the asset
+DesignPressureAttr : PressureAttr <abstract> { design }
+
+// Pump design pressure of the asset
+PumpDesignPressureAttr : DesignPressureAttr { pump }
+
+// Fan design pressure of the asset
+FanDesignPressureAttr : DesignPressureAttr { fan }
+
+// Chiller design pressure of the asset
+ChillerDesignPressureAttr : DesignPressureAttr { chiller }
+
+//////////////////////////////////////////////////////////////////////////
+// Rated pressure attributes
+//////////////////////////////////////////////////////////////////////////
+
+// Rated pressure of the asset
+RatedPressureAttr : PressureAttr <abstract> { rated }
+
+// Min chiller rated pressure of the asset
+MinChillerRatedPressureAttr : RatedPressureAttr { min, chiller }
\ No newline at end of file
diff --git a/src/xeto/ph.attrs/temp.xeto b/src/xeto/ph.attrs/temp.xeto
index 7efc4ce..c193b9a 100644
--- a/src/xeto/ph.attrs/temp.xeto
+++ b/src/xeto/ph.attrs/temp.xeto
@@ -14,3 +14,40 @@ MinRatedOperatingTempAttr : RatedOperatingTempAttr { min }
 
 // Maximum rated operating temperature of the asset
 MaxRatedOperatingTempAttr : RatedOperatingTempAttr { max }
+
+//////////////////////////////////////////////////////////////////////////
+// Design temp attributes
+//////////////////////////////////////////////////////////////////////////
+
+// Design temperature of the asset
+DesignTempAttr : TempAttr <abstract> { design }
+
+// Air design temperature of the asset
+AirDesignTempAttr: DesignTempAttr <abstract> { air }
+
+// Water entering design temperature of the asset
+WaterEnteringDesignTempAttr : EnteringDesignTempAttr <abstract>  { water }
+
+// Water leaving design temperature of the asset
+WaterLeavingDesignTempAttr : LeavingDesignTempAttr <abstract>  { water }
+
+// Leaving design temperature of the asset
+LeavingDesignTempAttr : DesignTempAttr <abstract> { leaving }
+
+// Entering design temperature of the asset
+EnteringDesignTempAttr : DesignTempAttr <abstract> { entering }
+
+// Hot water leaving design temperature of the asset
+HotWaterLeavingDesignTempAttr : WaterLeavingDesignTempAttr  { hot }
+
+// Chilled water leaving design temperature of the asset
+ChilledWaterLeavingDesignTempAttr : WaterLeavingDesignTempAttr  { chilled }
+
+// Hot water entering design temperature of the asset
+HotWaterEnteringDesignTempAttr : WaterEnteringDesignTempAttr  { hot }
+
+// Chilled water entering design temperature of the asset
+ChilledWaterEnteringDesignTempAttr : WaterEnteringDesignTempAttr  { chilled }
+
+// Discharge air design temperature of the asset
+DischargeAirDesignTempAttr: AirDesignTempAttr { discharge }
\ No newline at end of file