Table of Contents
HPXML allows the specification of multiple
Attic elements, each of which
relates to a
Roof element. That relation is optional in HPXML, but is
required for HEScore when there is more than one
because it is important to know which roof relates to each attic space.
An area is required for each
Attic element if there is more than one
Attic element. If there is only one
Attic element, the footprint area
of the building is assumed.
Attic is considered and the
AtticType is mapped into a HEScore roof
type according to the following mapping.
|venting unknown attic||vented_attic|
There is no way to get a HEScore
Items that are not translated will result in a translation error.
HEScore can accept up to two attic/roof constructions. If there are more than
two specified in HPXML, the properties of the
Attic elements with
the same roof type are combined. For variables with a discrete selection the
value that covers the greatest combined area is used. For R-values a
calculation is performed to determine the equivalent overall R-value for the
attic. This is discussed in more detail in Roof R-value.
Roof color in HEScore is mapped from the HPXML
according to the following mapping.
HEScore allows for more detailed roof color descriptions than HPXML. There is no way in HPXML to specify the following HEScore roof colors:
- cool_color (along with the absorptivity, which is also missing an HPXML element.)
HPXML stores the exterior finish information in the
This is translated into the HEScore exterior finish variable according to the
|slate or tile shingles||concrete tile|
|wood shingles or shakes||wood shakes|
|asphalt or fiberglass shingles||composition shingles|
|metal surfacing||composition shingles|
|expanded polystyrene sheathing||not translated|
|plastic/rubber/synthetic sheeting||tar and gravel|
|cool roof||not translated|
|green roof||not translated|
|no one major type||not translated|
Items where the HEScore translation indicates not translated above will result in a translation error.
AtticRoofInsulation element has a
Layer with the “continuous”
InsulationMaterial/Rigid, and a
greater than zero, the roof is determined to have rigid foam sheathing and one
of the construction codes is selected accordingly. Otherwise one of the
standard wood frame construction codes is selected.
<Attic> <SystemIdentifier id="attic5"/> <AttachedToRoof idref="roof3"/> <AtticType>cathedral ceiling</AtticType> <AtticRoofInsulation> <SystemIdentifier id="attic5roofins"/> <Layer> <InstallationType>continuous</InstallationType> <InsulationMaterial> <Rigid>eps</Rigid> </InsulationMaterial> <NominalRValue>10</NominalRValue> </Layer> </AtticRoofInsulation> <Area>2500</Area> </Attic>
Roof/RadiantBarrier element exists and has a “true” value, the attic
is assumed to have a radiant barrier and no roof deck insulation is assumed
according to the construction codes available in HEScore.
R-values for the roof deck are added up by summing the values of the
Layer/NominalRValue. If the roof construction was determined to have
Rigid Foam Sheathing, an R-value of 5 is subtracted from the roof R-value sum
to account for the R-value of the sheathing in the HEScore construction.
If the house has more than one
Attic element with roof insulation, the
insulation values are combined by first selecting the nearest roof
center-of-cavity R-value for each roof area from the table below.
|Exterior||Composition or Metal||Wood Shakes||Clay Tile||Concrete Tile||Tar and Gravel|
|w/ Radiant Barrier|
|w/ foam sheeting|
Then a weighted average is calculated by weighting the U-values by area.
The R-0 effective center-of-cavity R-value () is selected for the highest weighted roof construction type represented in the calculation and is subtracted from .
Finally the R-value is rounded to the nearest insulation level in the enumeration choices for the highest weighted roof construction type included in the calculation.
Determining the attic floor insulation levels uses the same procedure as Roof R-value except the lookup table is different. The attic floor center-of-cavity R-values are each R-0.5 greater than the nominal R-values in the enumeration list.
If the primary roof type is determined to be a cathedral ceiling, then an attic R-value is not calculated.