SAP NHER Technical Bulletin
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Transcript of SAP NHER Technical Bulletin
OCDEA Technical Bulletin Issue 31 Version 4.1 | ©National Energy Services 2012
Page 1 of 16
External wall junctions
E1–Steel lintels perforated base ...................... 4
E2–Other lintels ............................................... 4
E3–Sill ............................................................. 5
E4–Jamb .......................................................... 5
E5–Ground floor .............................................. 6
E6–Intermediate floor within
dwelling.................................................... 7
E7–Intermediate floor between
dwellings (flats) ....................................... 8
E8–Balcony within dwelling ............................. 8
E9–Balcony between dwelling ......................... 9
E10–Eaves (ceiling insulation) ........................ 9
E11–Eaves (rafter insulation) ........................ 10
E12–Gable (ceiling insulation) ....................... 10
E13–Gable (rafter insulation) ........................ 11
E14–Flat roof ................................................. 11
Contents: Table K1 items and their associated ACDs
E15–Flat roof with parapet ............................ 12
E16–Corner (normal) .................................... 12
E17–Corner (inverted) .................................. 13
E18–Party Wall between
dwellings (party corner)...................... 13
Party wall junctions
P1–Ground floor .............................................. 14
P2–Intermediate floor within
dwellings ................................................. 14
P3–Intermediate floor between
dwellings (flats) ...................................... 15
P4–Roof (ceiling insulation) ............................ 15
P5–Roof (rafter insulation) ............................. 16
OCDEAOCDEAOCDEA TechnicalTechnicalTechnical BulletinBulletinBulletin For On Construction Domestic Energy AssessorsFor On Construction Domestic Energy AssessorsFor On Construction Domestic Energy Assessors
Special EditionSpecial EditionSpecial Edition–––Thermal BridgingThermal BridgingThermal Bridging
Issue 31 Version 4.1| October 2012
All content © National Energy Services, Ltd
This is Version 4.1 of the special edition of the NHER OCDEA Technical Bulletin, first published
in July 2011. The special issue was produced to help our OCDEAs, NHER Plan Assessor users
and their customers to better understand how thermal bridging is dealt with in SAP 2009.
It describes the thermal bridging junctions in Table K1 of the SAP 2009 document and the
associated Accredited Construction Details (England and Wales) for each junction. It also
indicates where junction details and associated ѱ values are available from other sources: EST
Enhanced Construction Details, Scottish Accredited Construction Details, Association for
Energy Conscious Buildings and Constructive Details from BBA/RDL.
Web links are provided at the end of this bulletin for each of these sources. Junction details and
ѱ values are also available from some manufacturers.
OCDEA Technical Bulletin Issue 31 Version 4.1 | ©National Energy Services 2012
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Source: The Government’s Standard Assessment; Procedure for Energy Rating of Dwellings; 2009 edition;
incorporating RDSAP 2009; BRE, p. 78
*
OCDEA Technical Bulletin Issue 31 Version 4.1 | ©National Energy Services 2012
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The second diagram above assumes a room in the roof. If no roof room is present and the
ceiling is not insulated, omit E6 and P2 (unless the ceiling is clearly a structural element).
OCDEA Technical Bulletin Issue 31 Version 4.1 | ©National Energy Services 2012
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External wall: Steel lintel (perforated base plate)
—ACD ѱ = 0.5 (default = 1.0) E1
The length of the junction is the length of the
opening in the wall.
In NHER Plan Assessor the lintel length can
be set automatically from the opening width.
Typical example: MCI-WD-01
Masonry:
MCI-WD-01 MII-WD-01
Accredited (Indicative) Detail Number:
MCI-WD-01
External wall: Other lintels—ACD Ѱ = 0.3 (default = 1.0)
E2
The length of the junction is the length of the opening in the wall.
In NHER Plan Assessor the lintel length can be set automatically from the opening width.
Typical example: MCIWD-02
Masonry:
MCI-WD-02
MCI-WD-03
MII-WD-02
MII-WD-03
MEI-WD-01
Steel Framed:
SFW-WD-01
Timber Framed:
TFW-WD-01
Accredited (Indicative) Detail
Number: MCI-WD-02
Scottish Details: 1.08, 2.08, 3.08; Scottish ACDs
also include details for roof lights (5.01, 5.02).
Various EST Enhanced Construction Details are
available with ѱ values of less than 0.1.
The AECB Silver Standard has a junction with a
Ѱ value of 0.06 (calculated with internal
dimensions).
Various Constructive Details are available with
Ѱ values between 0.054 and 0.060.
Various EST Enhanced Construction
Details are available with ѱ values of less
than 0.1.
Various Constructive Details are available
with Ѱ values between 0.28 and 0.38.
EST ECD MV01 lintel
with ѱ = 0.01
OCDEA Technical Bulletin Issue 31 Version 4.1 | ©National Energy Services 2012
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External wall: Sill—ACD Ѱ = 0.04 (default = 0.08)
E3 Masonry:
MCI-WD-04
MII-WD-04
MEI-WD-02
Steel Framed:
SFW-WD-02
Timber
Framed:
TFW-WD-02
Typical example: SFW-WD-02
Accredited (Indicative) Detail Number:
SFW-WD-02
External wall: Jamb—ACD Ѱ = 0.05 (default = 0.10)
E4
The length of the jamb is the length of the opening in the wall.
In NHER Plan Assessor the jamb can be set automatically from the opening height.
Masonry:
MCI-WD-05 MCI-WD-06 MII-WD-05 MII-WD-06 MEI-WD03
Steel Framed:
SFW-WD-03
Timber Framed:
TFW-WD-03
Typical example: SFW-WD-03
The length of the junction is the length of the
opening in the wall.
In NHER Plan Assessor the sill length can be set
automatically from the opening width.
Scottish Details: 1.09, 2.09, 3.09
The AECB Silver Standard has a junction with
a ѱ value = 0.03.
Various Constructive Details are available
with Ѱ values between 0.034 and 0.046.
Scottish Details:1.09, 2.09, 3.09
The AECB Silver Standard has a junction with a
ѱ value of 0.03.
Various Constructive Details are available with Ѱ
values between 0.039 and 0.051.
Accredited (Indicative) Detail Number:
SFW-WD-03
OCDEA Technical Bulletin Issue 31 Version 4.1 | ©National Energy Services 2012
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External wall: Ground floor––ACD Ѱ = 0.16 (default = 0.32)
Masonry:
MCI-GF-01
MCI-GF-02
MCI-GF-03
MII-GF-01
MII-GF-02
MII-GF-03
MEI-GF-01
MEI-GF-02
MEI-GF-03
Steel Framed:
SFW-GF-01 SFW-GF-02
Timber Framed:
TFW-GF-01
TFW-GF-02
TFW-GF-03
E5
Accredited (Indicative) Detail Number: MCI-GF-03
Scottish Details:
1.10, 2.10, 3.10; 1.11, 2.11, 3.11; 1.12, 2.12,
3.12
Various EST Enhanced Construction Details are available, with ѱ values in cases less than 0.04. The AECB Silver Standard has junctions with
ѱ values of between 0.01 and 0.10.
Various Constructive Details are available with
Ѱ value between 0.025 and 0.160.
EST Enhanced Construction Detail MV01 F02 with ѱ = 0.075
Note: for all junctions the ѱ value depends on
the level of insulation in the adjoining elements.
The ѱ value can increase as the level of insula-
tion increases. However, the ACDs (England and
Wales, Scotland) do not prescribe insulation
thicknesses for which the ѱ values apply. The
other options (EST, AECB, CD) are more pre-
scriptive to varying degrees.
Measure the ground floor perimeter of the prop-
erty. Include perturbations (like bay windows)
and any other wall to ground floor lengths.
Floors above unheated space or exposed upper
floors should also be counted as this type.
Example of E5 dimension
OCDEA Technical Bulletin Issue 31 Version 4.1 | ©National Energy Services 2012
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Masonry:
MCI-IF-01
MCI-IF-02
MII-IF-01
MII-IF-02
MEI-IF-01
Steel Framed:
SFW-IF-01
Timber Framed:
TFW-IF-01
External Wall: intermediate floor within a dwelling
—ACD Ѱ = 0.07 (default = 0.14) E6
Typical example:
Scottish Details:
1.14, 2.14, 3.14; 1.15, 2.15, 3.15.
The AECB Silver Standard has junctions with
ѱ values of between 0.00 and 0.03.
Various Constructive Details are available with
a Ѱ value of 0.00. Accredited (Indicative) Detail Number:
MII-IF-02
A floor above a heated basement should be
included in this length.
Enter the perimeter of all external intermediate
floors. These include roof room floors to gables
or to walls where the eaves are above the RIR
floor level.
OCDEA Technical Bulletin Issue 31 Version 4.1 | ©National Energy Services 2012
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External wall: Balcony within dwelling–No ACD (default Ѱ = 0.0 or 1.0)
E8
Typical example: MCI-IF-01 Masonry:
MCI-IF-01 MII-IW-01 MEI-IF-01
This is the external floor perimeter of a flat with another dwelling below. In mid-floor flats this would
also be the ceiling. This should also be used for floors above separate heated spaces such as commercial
premises.
E7 External wall: Intermediate floor between dwellings
—ACD Ѱ = 0.07 (default = 0.14)
No ACDs available.
This DCLG SAP Convention
supersedes and replaces the
*footnote in Table K1.
A default value of 0.00 can be used
if the balcony supports do not
bridge the insulation. Otherwise use
a default value of 1.0 or a
calculated value.
Accredited (Indicative) Detail Number:
MCI-IF-01
The diagram shows the Scottish ACD 5.11 (for which no ѱ value is quoted).
Various Constructive Details are available with Ѱ values between 0.057 and 0.093.
OCDEA Technical Bulletin Issue 31 Version 4.1 | ©National Energy Services 2012
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Typical example: MII-RE-05* Masonry:
MCI-RE-01
MCI-RE-02
MCI-RE-03*
MCI-RE-05*
MII-RE-01
MII-RE-02
MII-RE-03*
MII-RE-05*
MEI-RE-01
MEI-RE-02
MEI-RE-03*
MEI-RE-05*
Steel Framed:
SFW-RE-01
SFW-RE-02
SFW-RE-03*
SFW-RE-05
Timber Framed:
TFW-RE-01
TFW-RE-02
TFR-RE-03*
TFW-RE-05*
External wall: Eaves (ceiling insulation)
—ACD Ѱ = 0.06 (default = 0.12)
Accredited (Indicative) Detail Number: MII-RE-05
Length of eaves entered.
All wall to eaves bridges should be classified under this junction, this includes bay window walls and
dormer walls.
*Included here as main junction is eaves to roof with insulation over joist at that point.
E10
External wall: balcony between dwellings–
No ACD (default Ѱ = 0.04 or 1.0) E9
No ACDs available.
This DCLG SAP Convention supersedes and replaces the
footnote in Table K1.
A default value of 0.04 can be used if the balcony supports
do not bridge the insulation. Otherwise use a default value of
1.0 or a calculated value.
Scottish Details:1.01, 2.01, 3.01
Various Constructive Details are available with Ѱ values between 0.064 and 0.128.
OCDEA Technical Bulletin Issue 31 Version 4.1 | ©National Energy Services 2012
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Typical example: MEI-RE-04
Masonry:
MCI-RE-04
MCI-RE-06
MCI-RE-07
MCI-RE-08
MII-RE-04
MII-RE-06
MII-RE-07
MII-RE-08
MEI-RE-04
MEI-RE-06
MEI-RE-07
MEI-RE-08
Steel Framed:
SFW-RE-04
SFW-RE-06
SFW-RE-07
SFW-RE-08
Timber Framed:
TFW-RE-04
TFW-RE-06
TFW-RE-07
TFW-RE-08
External wall: Eaves (rafter insulation)—ACD Ѱ = 0.04 (default = 0.08)
Lengths of eaves entered. All wall to eaves bridges should be classified under this junction; this includes
bay windows and dormer walls.
Masonry:
MCI-RG-01
MII-RG-01
MEI-RG-01
Steel Framed:
SFW-RG-01
Timber Framed:
TFW-RG-01
External wall: Gable (ceiling insulation)—ACD Ѱ = 0.24 (default = 0.48)
E11
E12
Scottish Details: 1.04, 2.04, 3.04
The AECB Silver Standard has junctions
with ѱ values of between 0.00 and 0.044.
Various Constructive Details are available
with Ѱ between 0.02 and 0.036.
Various EST Enhanced Construction Details are available, with
ѱ values substantially less than 0.1.
Various Constructive Details are available with Ѱ values between
0.048 and 0.087.
Accredited (Indicative) Detail
Number: MEI-RE-04
Typical example: TFW-RG-01
Accredited (Indicative) Detail Number:
TFW-RG-01
Scottish Details: 1.02, 2.02, 3.02; 1.03, 2.03, 3.03; 1.05, 2.05, 3.05
All wall to gable bridges should be classified under this junction; this includes bay window walls and
dormer walls.
OCDEA Technical Bulletin Issue 31 Version 4.1 | ©National Energy Services 2012
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Typical example: TFW-RG-04 Masonry:
MCI-RG-02
MCI-RG-03
MCI-RG-04
MII-RG-02
MII-RG-03
MII-RG-04
MEI-RG-02
MEI-RG-03
MEI-RG-04
Steel Framed:
SFW-RG-02 SFW-RG-03 SFW-RG-04
Timber Framed:
TFW-RG-02 TFW-RG-03 TFW-RG-04
External wall: Gable (rafter insulation)—ACD Ѱ = 0.04 (default = 0.08)
E13
Typical example: MCI-RF-01
Masonry:
MCI-RF-01
MII-RF-01
MEI-RF-01
Steel Framed:
SFW-RF-01
External wall: Flat roof—ACD Ѱ = 0.04 (default = 0.08)
E14
Accredited (Indicative) Detail Number: MCI-RF-01
Scottish Details: 1.06, 2.06, 3.06
Accredited (Indicative) Detail Number: TFW-RG-04 Various Constructive Details are available with Ѱ values between 0.065 and 0.073.
All wall to gable bridges should be classified under this junction; this includes bay window walls and
dormer walls.
All wall to flat roof bridges should be classified
under this junction; this includes bay window
walls and dormer walls.
OCDEA Technical Bulletin Issue 31 Version 4.1 | ©National Energy Services 2012
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Masonry:
MCI-RF-02
MII-RF-02
MEI-RF-02
Steel Framed:
SFW-RF-02
Timber Framed:
TFW-RF-01
External wall: Flat roof with parapet—ACD Ѱ = 0.28 (default = 0.56)
E15
Further clarification is given in the DCLG SAP Conventions
document: “From the thermal bridging point of view the
principal difference between a parapet and not is whether
the wall passes over the edge of the roof, or the roof
passes over the top of the wall.
These two possibilities form different types of junction. If
the wall passes over the edge of the roof, treat as a roof
with parapet. If the roof passes over the top of the wall,
treat it as a roof without a parapet.”
All wall to flat roof bridges should be classified under this
junction, this includes bay window walls and dormer walls.
Timber Framed:
TFW-EW-01
External wall: Corner (normal)—ACD Ѱ = 0.09 (default = 0.18)
E16
Height of wall to wall corners where internal area is less than external area.
Also describes:
Dormer corners
Corners to unheated garage
There are no England and Wales ACD options available for masonry construction
types; use default ѱ value or a value from another source. If the construction around
the corner is the same as the rest of the dwelling and not interrupted by structural
elements the ACD value of 0.09 can still be used. Ignore corners in bay windows if
the insulation is continuous.
Typical example: TFW-EW-01
Accredited (Indicative) Detail Number:
TFW-EW-01
Accredited (Indicative) Detail Number:
TFW-RF-02
Scottish Details: 1.07, 2.07, 3.07
The AECB Silver Standard has junctions with ѱ values
of between 0.12 and 0.25.
Scottish Details: 1.23, 2.23,
3.23
The AECB Silver Standard
has a masonry junction with a
ѱ value of 0.066 (ref 2.2.2).
Various Constructive Details are available with Ѱ values between 0.04 and 0.056.
Typical example: TFW-RF-02
OCDEA Technical Bulletin Issue 31 Version 4.1 | ©National Energy Services 2012
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External wall: Corner (inverted)–No ACD (default Ѱ = 0.00)
E17
No ACDs available. A value of ѱ = 0.0 is
normally used. However, there is a Scottish
ACD with ѱ = -0.119.
Typical example
Example of E18 dimensions Masonry:
MCI-IW-01
MII-IW-01
MEI-IW-01
MEI-IW-02
Steel Framed:
SFW-IW-01
SFW-IW-02
Timber
Framed:
TFW-IW-01
TFW-IW-02
External wall: Party wall between dwellings
––ACD Ѱ = 0.06 (default = 0.12)
Front elevation
E18
Accredited (Indicative) Detail Number:
MCI-IW-01
Scottish Details:1.13, 2.13, 3.13
This is the corner between the external wall
and the party wall.
Scottish Details: 1.24, 2.24, 3.24
Various Constructive Details are available
with ѱ values between -0.08 and -0.052.
Various Constructive Details are available with
ѱ values between 0.035 and 0.046.
OCDEA Technical Bulletin Issue 31 Version 4.1 | ©National Energy Services 2012
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Party wall: Intermediate floor within dwelling–
No ACD (default Ѱ = 0.04) P2 Typical example
Party wall: Ground floor –No ACD (default Ѱ = 0.16)
P1
No ACDs available–use default or calculated
value from another source.
Also use for junction with heated corridor/
stairwells or other heated spaces.
Typical example
Scottish Details: 1.16, 2.16, 3.16; 1.17,
2.17, 3.17; 1.18, 2.18, 3.18
No ACDs available–use default or calculated
value from another source.
The default of 0.04 can also be used for houses
with a split level arrangement.
Disregard intermediate floor junction with walls
adjacent to heated corridor/stairwells or other
heated spaces.
Various Constructive Details are available
with ѱ values between 0.043 and 0.073.
OCDEA Technical Bulletin Issue 31 Version 4.1 | ©National Energy Services 2012
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Party wall: Intermediate floor between dwellings–
No ACD( default Ѱ = 0.04) P3
Party wall: Roof (ceiling insulation)—ACD Ѱ = 0.12 (default = 0.24)
P4 Typical example: TFW-IW-02
Masonry:
MEI-IW-02
MCI-IW-02
MII-IW-02
Steel Framed:
SFW-IW-02
Timber Framed:
TFW-IW-02
Scottish Details: 1.21, 2.21, 3.21
No ACDs available–use default or calculated value from an-
other source.
The default value of 0.04 can also be used for flats with a
split level arrangement. Use this value for each flat.
Disregard intermediate floor junction with walls adjacent to
heated corridor/stairwells or other heated spaces.
Accredited (Indicative) Detail Number:
TFW-IW-02
Also used for roof adjacent to heated corridor/
stairwells or other heated spaces.
Various Constructive Details are available with ѱ values between 0.041 and 0.087.
Party wall: Roof (rafter insulation)–No ACD (default Ѱ = 0.04)
P5
Further information:
The Accredited Construction Details for England and Wales can be found by visiting the Planning Portal Website.
The EST Enhanced Construction Details can be found by visiting the EST website. These provide alternative details
to ACDs for E1, E2, E5 and E12, with substantially lower ѱ values.
BBA and Robust Details Ltd have junction details under the name Constructive Details. Details of the scheme can be
found here: www.constructivedetails.co.uk/
The Scottish Accredited Construction Details can be found by clicking here. Scottish Details can be used in England
and Wales if the construction matches.
The Association for Energy Conscious Buildings (AECB) also have junction details and associated ѱ values available to
members. Details of membership are available by visiting: www.aecb.net. Their design guidance for the Silver and
Gold standards provides detailed guidance on how to minimise thermal bridging.
All ѱ values from these above sources can be taken as being produced by someone with suitable expertise and
experience for the purposes of Building Regulation submissions.
This technical bulletin is consistent with DCLG SAP Conventions (v4.0), dated 12 September 2012. The DCLG SAP
Conventions are a key reference and provide further detail and background; the DCLG Conventions can be found in
‘NES one useful documents’ and at the BRE website.
No ACDs available–use default or calculated values from another
source. Also used for roof adjacent to heated corridor/stairwells or
other heated spaces.
Scottish Details: 1.22, 2.22, 3.22
Dormers
Dormers are not specifically included in Table K1. However, a convention exists for how to enter them
into SAP software. The Scottish ACDs 5.04 and 5.05 include some junctions for dormers.
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Email: [email protected]; www.nesltd.co.uk
AB O UT O UR B UL L ET IN S We trust you find this edition of the technical bulletin useful. If there are any areas you would like to see covered in future editions drop us a line at [email protected] Back copies of all bulletins are available in the Useful Documents section of NES one.
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Typical example
Various Constructive Details are available with ѱ values between 0.069 and 0.071.