Create Add DiscountRate.md

BuildingSync.xsd

@@ -4564,7 +4564,7 @@
         </xs:annotation>
         <xs:complexType>
           <xs:simpleContent>
-            <xs:extension base="xs:decimal">
+            <xs:extension base="xs:nonNegativeInteger">
               <xs:attribute ref="auc:Source"/>
             </xs:extension>
           </xs:simpleContent>
@@ -4777,6 +4777,20 @@
       <xs:element name="DiscountFactor" minOccurs="0">
         <xs:annotation>
           <xs:documentation>Discount factor applied to calculate present values of future cash flows. (0-100) (%)</xs:documentation>
+          <xs:documentation>Discount factors $v$ are related to discount rates $i$ by the following equation: $v=\frac{1}{1+i}$.</xs:documentation>
+        </xs:annotation>
+        <xs:complexType>
+          <xs:simpleContent>
+            <xs:extension base="xs:decimal">
+              <xs:attribute ref="auc:Source"/>
+            </xs:extension>
+          </xs:simpleContent>
+        </xs:complexType>
+      </xs:element>
+      <xs:element name="DiscountRate" minOccurs="0">
+        <xs:annotation>
+          <xs:documentation>Discount rate applied to calculate present values of future cash flows. (0-100) (%)</xs:documentation>
+          <xs:documentation>Discount rates $i$ are related to discount factors $v$ by the following equation: $i=\frac{1-v}{v}$ where $v \neq 0$.</xs:documentation>
         </xs:annotation>
         <xs:complexType>
           <xs:simpleContent>

examples/AT_example_NYC_audit_report_property.xml

@@ -4223,7 +4223,7 @@
             <auc:OMCostAnnualSavings>3000.0</auc:OMCostAnnualSavings>
             <auc:FundingFromIncentives>500.0</auc:FundingFromIncentives>
           </auc:MeasureSavingsAnalysis>
-          <auc:UsefulLife>6.0</auc:UsefulLife>
+          <auc:UsefulLife>6</auc:UsefulLife>
           <auc:MeasureTotalFirstCost>10000.0</auc:MeasureTotalFirstCost>
           <auc:Recommended>true</auc:Recommended>
           <auc:UserDefinedFields>
@@ -4260,7 +4260,7 @@
             <auc:OMCostAnnualSavings>900.0</auc:OMCostAnnualSavings>
             <auc:FundingFromIncentives>200.0</auc:FundingFromIncentives>
           </auc:MeasureSavingsAnalysis>
-          <auc:UsefulLife>10.0</auc:UsefulLife>
+          <auc:UsefulLife>10</auc:UsefulLife>
           <auc:MeasureTotalFirstCost>1800.0</auc:MeasureTotalFirstCost>
           <auc:ImplementationStatus>Proposed</auc:ImplementationStatus>
           <auc:UserDefinedFields>
@@ -4297,7 +4297,7 @@
             <auc:OMCostAnnualSavings>2800.0</auc:OMCostAnnualSavings>
             <auc:FundingFromIncentives>1500.0</auc:FundingFromIncentives>
           </auc:MeasureSavingsAnalysis>
-          <auc:UsefulLife>15.0</auc:UsefulLife>
+          <auc:UsefulLife>15</auc:UsefulLife>
           <auc:MeasureTotalFirstCost>50000.0</auc:MeasureTotalFirstCost>
           <auc:ImplementationStatus>Proposed</auc:ImplementationStatus>
           <auc:UserDefinedFields>
@@ -4334,7 +4334,7 @@
             <auc:OMCostAnnualSavings>1200.0</auc:OMCostAnnualSavings>
             <auc:FundingFromIncentives>500.0</auc:FundingFromIncentives>
           </auc:MeasureSavingsAnalysis>
-          <auc:UsefulLife>10.0</auc:UsefulLife>
+          <auc:UsefulLife>10</auc:UsefulLife>
           <auc:MeasureTotalFirstCost>20000.0</auc:MeasureTotalFirstCost>
           <auc:Recommended>true</auc:Recommended>
           <auc:UserDefinedFields>
@@ -4371,7 +4371,7 @@
             <auc:OMCostAnnualSavings>1800.0</auc:OMCostAnnualSavings>
             <auc:FundingFromIncentives>0.0</auc:FundingFromIncentives>
           </auc:MeasureSavingsAnalysis>
-          <auc:UsefulLife>12.0</auc:UsefulLife>
+          <auc:UsefulLife>12</auc:UsefulLife>
           <auc:MeasureTotalFirstCost>10000.0</auc:MeasureTotalFirstCost>
           <auc:ImplementationStatus>Evaluated</auc:ImplementationStatus>
           <auc:UserDefinedFields>
@@ -4408,7 +4408,7 @@
             <auc:OMCostAnnualSavings>150.0</auc:OMCostAnnualSavings>
             <auc:FundingFromIncentives>100.0</auc:FundingFromIncentives>
           </auc:MeasureSavingsAnalysis>
-          <auc:UsefulLife>20.0</auc:UsefulLife>
+          <auc:UsefulLife>20</auc:UsefulLife>
           <auc:MeasureTotalFirstCost>400.0</auc:MeasureTotalFirstCost>
           <auc:Recommended>true</auc:Recommended>
           <auc:UserDefinedFields>
@@ -4445,7 +4445,7 @@
             <auc:OMCostAnnualSavings>200.0</auc:OMCostAnnualSavings>
             <auc:FundingFromIncentives>50.0</auc:FundingFromIncentives>
           </auc:MeasureSavingsAnalysis>
-          <auc:UsefulLife>20.0</auc:UsefulLife>
+          <auc:UsefulLife>20</auc:UsefulLife>
           <auc:MeasureTotalFirstCost>250.0</auc:MeasureTotalFirstCost>
           <auc:Recommended>true</auc:Recommended>
           <auc:UserDefinedFields>
@@ -4482,7 +4482,7 @@
             <auc:OMCostAnnualSavings>100.0</auc:OMCostAnnualSavings>
             <auc:FundingFromIncentives>0.0</auc:FundingFromIncentives>
           </auc:MeasureSavingsAnalysis>
-          <auc:UsefulLife>20.0</auc:UsefulLife>
+          <auc:UsefulLife>20</auc:UsefulLife>
           <auc:MeasureTotalFirstCost>300.0</auc:MeasureTotalFirstCost>
           <auc:Recommended>true</auc:Recommended>
           <auc:UserDefinedFields>
@@ -4519,7 +4519,7 @@
             <auc:OMCostAnnualSavings>300.0</auc:OMCostAnnualSavings>
             <auc:FundingFromIncentives>1000.0</auc:FundingFromIncentives>
           </auc:MeasureSavingsAnalysis>
-          <auc:UsefulLife>10.0</auc:UsefulLife>
+          <auc:UsefulLife>10</auc:UsefulLife>
           <auc:MeasureTotalFirstCost>4800.0</auc:MeasureTotalFirstCost>
           <auc:Recommended>true</auc:Recommended>
           <auc:UserDefinedFields>
@@ -4556,7 +4556,7 @@
             <auc:OMCostAnnualSavings>150.0</auc:OMCostAnnualSavings>
             <auc:FundingFromIncentives>0.0</auc:FundingFromIncentives>
           </auc:MeasureSavingsAnalysis>
-          <auc:UsefulLife>10.0</auc:UsefulLife>
+          <auc:UsefulLife>10</auc:UsefulLife>
           <auc:MeasureTotalFirstCost>1200.0</auc:MeasureTotalFirstCost>
           <auc:Recommended>true</auc:Recommended>
           <auc:UserDefinedFields>

examples/AT_example_SF_audit_report.xml

@@ -2387,7 +2387,7 @@ This example is configured to import and export with BuildingSync version 2.2.0.
           <auc:MeasureSavingsAnalysis>
             <auc:FundingFromIncentives>10000.0</auc:FundingFromIncentives>
           </auc:MeasureSavingsAnalysis>
-          <auc:UsefulLife>20.0</auc:UsefulLife>
+          <auc:UsefulLife>20</auc:UsefulLife>
           <auc:MeasureTotalFirstCost>300000.0</auc:MeasureTotalFirstCost>
           <auc:Recommended>true</auc:Recommended>
           <auc:UserDefinedFields>
@@ -2420,7 +2420,7 @@ This example is configured to import and export with BuildingSync version 2.2.0.
           <auc:MeasureSavingsAnalysis>
             <auc:FundingFromIncentives>500.0</auc:FundingFromIncentives>
           </auc:MeasureSavingsAnalysis>
-          <auc:UsefulLife>15.0</auc:UsefulLife>
+          <auc:UsefulLife>15</auc:UsefulLife>
           <auc:MeasureTotalFirstCost>2500.0</auc:MeasureTotalFirstCost>
           <auc:ImplementationStatus>Proposed</auc:ImplementationStatus>
           <auc:UserDefinedFields>

examples/BuildingSync Website Invalid Schema.xml

@@ -514,7 +514,7 @@
         </auc:CalculationMethod>
         <auc:FundingFromIncentives>1000.0</auc:FundingFromIncentives>
       </auc:MeasureSavingsAnalysis>
-      <auc:UsefulLife>8.0</auc:UsefulLife>
+      <auc:UsefulLife>8</auc:UsefulLife>
       <auc:MeasureTotalFirstCost>30000.0</auc:MeasureTotalFirstCost>
       <auc:Recommended>true</auc:Recommended>
       <auc:UserDefinedFields>
@@ -540,7 +540,7 @@
         </auc:CalculationMethod>
         <auc:FundingFromIncentives>100.0</auc:FundingFromIncentives>
       </auc:MeasureSavingsAnalysis>
-      <auc:UsefulLife>2.0</auc:UsefulLife>
+      <auc:UsefulLife>2</auc:UsefulLife>
       <auc:MeasureTotalFirstCost>500.0</auc:MeasureTotalFirstCost>
       <auc:Recommended>true</auc:Recommended>
       <auc:UserDefinedFields>
@@ -566,7 +566,7 @@
         </auc:CalculationMethod>
         <auc:FundingFromIncentives>50.0</auc:FundingFromIncentives>
       </auc:MeasureSavingsAnalysis>
-      <auc:UsefulLife>2.0</auc:UsefulLife>
+      <auc:UsefulLife>2</auc:UsefulLife>
       <auc:MeasureTotalFirstCost>100.0</auc:MeasureTotalFirstCost>
       <auc:Recommended>true</auc:Recommended>
       <auc:UserDefinedFields>

examples/BuildingSync Website Valid Schema.xml

@@ -328,7 +328,7 @@
           <auc:MeasureScaleOfApplication>Entire building</auc:MeasureScaleOfApplication>
           <auc:LongDescription>Install plug load controls</auc:LongDescription>
           <auc:MVCost>0</auc:MVCost>
-          <auc:UsefulLife>5.6</auc:UsefulLife>
+          <auc:UsefulLife>6</auc:UsefulLife>
           <auc:MeasureTotalFirstCost>56950.64</auc:MeasureTotalFirstCost>
           <auc:MeasureInstallationCost>0</auc:MeasureInstallationCost>
           <auc:MeasureMaterialCost>0</auc:MeasureMaterialCost>
@@ -568,7 +568,7 @@
           <auc:MeasureScaleOfApplication>Entire building</auc:MeasureScaleOfApplication>
           <auc:LongDescription>Replace ice/refrigeration equipment with high efficiency units</auc:LongDescription>
           <auc:MVCost>0</auc:MVCost>
-          <auc:UsefulLife>12.5</auc:UsefulLife>
+          <auc:UsefulLife>13</auc:UsefulLife>
           <auc:MeasureTotalFirstCost>135431.4</auc:MeasureTotalFirstCost>
           <auc:MeasureInstallationCost>0</auc:MeasureInstallationCost>
           <auc:MeasureMaterialCost>0</auc:MeasureMaterialCost>
@@ -778,7 +778,7 @@
           <auc:MeasureScaleOfApplication>Entire building</auc:MeasureScaleOfApplication>
           <auc:LongDescription>Improve ventilation fans</auc:LongDescription>
           <auc:MVCost>0</auc:MVCost>
-          <auc:UsefulLife>4.4</auc:UsefulLife>
+          <auc:UsefulLife>4</auc:UsefulLife>
           <auc:MeasureTotalFirstCost>69452.0</auc:MeasureTotalFirstCost>
           <auc:MeasureInstallationCost>0</auc:MeasureInstallationCost>
           <auc:MeasureMaterialCost>0</auc:MeasureMaterialCost>
@@ -838,7 +838,7 @@
           <auc:MeasureScaleOfApplication>Entire building</auc:MeasureScaleOfApplication>
           <auc:LongDescription>Add or repair economizer</auc:LongDescription>
           <auc:MVCost>0</auc:MVCost>
-          <auc:UsefulLife>12.5</auc:UsefulLife>
+          <auc:UsefulLife>13</auc:UsefulLife>
           <auc:MeasureTotalFirstCost>55561.600000000006</auc:MeasureTotalFirstCost>
           <auc:MeasureInstallationCost>0</auc:MeasureInstallationCost>
           <auc:MeasureMaterialCost>0</auc:MeasureMaterialCost>

proposals/2022/Add DiscountRate.md

@@ -0,0 +1,37 @@
+# Add Discount Rate
+
+## Overview
+
+This proposal is support the assertion of discount rates in BuildingSync XML schema.
+
+## Justification
+
+### Present Value Calculation
+
+The equation for net present value is:
+
+$$ NPV\left({i,N}\right) = \sum_{t=0}^{N}{\frac{R_{t}}{\left({1+i}\right)^t}} $$
+
+where
+* $i$ is the discount rate (percentage).
+* $N$ is the total number of periods (non-negative integer).
+* $t$ is the time of the cash flow (non-negative integer).
+* $R_{t}$ is the cash flow at time $t$ (decimal).
+
+Currently, BuildingSync XML schema supports the assertion of discount factors via the `<auc:DiscountFactor>` element, where the discount factor $v$ is related to the discount rate $i$ by the following equation:
+
+$$ v = \frac{1}{1 + i} $$
+
+### Service Life
+
+BuildingSync XML schema supports the assertion of the service life in years via the `<auc:UsefulLife>` element.
+Currently, the datatype is `xsd:decimal`, which allows for fractional and negative years.
+However, ASHRAE [reports](http://weblegacy.ashrae.org/publicdatabase/) median life in non-negative integer years.
+
+## Implementation
+
+The proposed implementation consists of 3 tasks:
+
+1. Add `<auc:DiscountRate>` element (non-breaking change).
+2. Add documentation to definitions of `<auc:DiscountFactor>` and `<auc:DiscountRate>` elements to clarify their mathematical relationship (non-breaking change).
+3. Constrain datatype of `<auc:UsefulLife>` element to `xsd:nonNegativeInteger` (breaking change).