Update of the
National Energy Code
for Buildings
Outline
 Recent history of the Energy Code development
in Canada
 National Energy Code for Buildings (NECB) 2011
• Impetus for updating the 1997 Model National
Energy Code for Buildings
• Approach used in NECB and details
2
History
Model National Energy Code for Buildings 1997
 Prescriptive approach: building envelope,
HVAC, service water heating, lighting,
electrical power
 Engineering approach: performance 
“Performance Compliance for Buildings”
• reference and proposed building modeling
 Model National Energy Code for
Houses (MNECH) published in 1997
3
History (cont’d)
 Total life-cycle costing
 Different construction requirements for
different energy sources
 Regional variations in energy costs
 Not widely adopted
4
Decision to Update
 June 2005 Canadian Commission on Building
and Fire Codes (CCBFC) meeting
• NRCan presentation and request for update
 Motion
• “Moved … and seconded … that CCBFC supports,
as a first phase, the work on the technical basis for
the development of the revisions to the MNECB as
a progeny document on condition that the necessary
support and funding for the project is provided from
NRCan and/or others.”
5
Decision to Update
 Building Energy Codes Collaborative (BECC)
• business plan
• P/T support
• funding from NRCan
 February 2007 CCBFC meeting
• “Moved by …, seconded by …, that the updating of the
MNECB as a progeny document based on the BECC
business plan be approved, subject to:
– the process to develop the document would follow
the policies and procedures of the Commission
– the work would not compromise the capacity to
complete the current and ongoing priorities of the
coordinated codes development system”
6
NECB 2011
 Standing Committee on Energy Efficiency in
Buildings (SC-EEB) formed in 2007
 First meeting in December 2007
 Task groups
• Building Envelope
• HVAC and Service Water Heating
• Lighting and Power
• Performance Compliance
• Code Consolidation
7
NECB 2011
 Objective-based
 Energy used by the building
 Paths of compliance
• Prescriptive path
• Trade-off path (within the Part)
• Performance path
 Simple payback approach
8
Task Group on Building Envelope
 Maximum overall thermal transmittances (U-values)
will not differ for different assembly construction
 Thermal requirements categorized by climate zone,
defined by heating degree days – six Canadian
climate zones
 Thermal requirements will be fuel source neutral
 Limitation on the fenestration and
door to wall ratio in the prescriptive
path
 Air barrier requirements are being
introduced for building envelope
assemblies
9
Task Group on Building Envelope (cont’d)
Existing Provisions
Table A-3.3.1.1.(1)
Prescriptive Requirements – Above-ground Building Assemblies
Forming Part of Sentence 3.3.1.1.(1)
Assembly Description
Principal Heating Source
Oil, Propane,
Electricity, Other
Natural Gas
Heat Pump
Maximum Overall Thermal Transmittance (U-value), W/m2 ºC
Roofs
Type I - attic-type roofs
0.140
0.200
0.200
Type II - parallel-chord trusses and joist-type roofs
0.230
0.230
0.230
0.290
0.410
0.470
0.330
0.480
0.550
0.220
0.220
0.220
0.290
0.410
0.470
Type III - all other roofs
(e.g., concrete decks with rigid insulation)
Walls
Floors
- parallel-chord trusses and
Type I
joist-type floors
- all other floors (e.g., concrete slabs
Type II
with rigid insulation)
10
Task Group on Building Envelope (cont’d)
Proposed Approach
Heating Degree-Days of Building Location(1), Celsius degree-days
Zone 4:
Zone 5:
Zone 6:
Zone 7A:
< 3000
3000 to 3999
4000 to 4999
5000 to 5999
Maximum Overall Thermal Transmittance (W/m2K)
In Contact With the Ground
Walls
0.568
0.379
0.284
0.284
Roofs
0.568
0.379
0.284
0.284
Floors 1
0.757
0.757
0.757
0.757
for 1.2 m
for 1.2 m
for 1.2 m
for 1.2 m
Above-Ground Component
Walls
0.315
Roofs
0.227
Floors
0.227
2
Fenestration
2.4
3
Doors
2.4
0.278
0.183
0.183
2.2
2.2
0.247
0.183
0.183
2.2
2.2
0.210
0.162
0.162
2.2
2.2
Zone 7B:
6000 to 6999
Zone 8:
≥ to 7000
0.284
0.284
0.757
for 1.2 m
0.210
0.210
0.379
full area
0.210
0.162
0.162
2.2
2.2
0.183
0.142
0.142
1.6
1.6
Table 1. Proposed Thermal Requirements for the NECB 2011
Notes to Table 1:
1 – floors in contact with the ground with imbedded heating cables or heating or cooling pipes require full area insulation in all heating-degree day categories
2 - exception of overall thermal transmittance of 3.4 W/m2K for skylights not exceeding 2% of gross roof area
3 - exception of overall thermal transmittance of 4.4 W/m2K for doors not exceeding 2% of gross wall area
11
Task Group on Building Envelope (cont’d)
 The maximum allowable total vertical fenestration
and door area to gross wall area (FDWR) will vary
by climate zone:

FDWR = 0.40 for HDD < 4000
FDWR ≤ (2.590 X 10-8)∙HDD2 – (3.516 X 10-4)∙HDD
+ 1.392, for 4000 ≤ HDD ≤ 7000
FDWR = 0.20 for HDD > 7000
12
Task Group on Building Envelope (cont’d)
0.45
FDWR
0.40
0.35
0.30
0.25
FDWR
0.20
0.15
0.10
0.05
0.00
3500
4500
HDD 5500
6500
7500
13
Task Group on Building Envelope (cont’d)
 Building envelope trade-off compliance path
• Scaled down version of the full performance path,
considering only building envelope elements
• Demonstration that the building envelope will not
use more energy than it would if all components
were to comply with the prescriptive path
14
Task Group on
Lighting and Electrical Power
Lighting
 Lighting requirements are generally being
harmonized with ASHRAE 90.1 2010
 Additional requirements for automatic control
devices, including automatic daylighting
controls
 Lighting power allowances
for building exteriors will be
introduced for more exterior
lighting applications
15
Task Group on
Lighting and Electrical Power (cont’d)
Lighting (cont’d)
 Lighting Power Density (LPD) tables updated
Lighting Power Densities
Using the Building Area Method
Building Area Type
W/m2
Automotive facility
9.79
Convention center
11.30
Courthouse
11.51
Dining: bar lounge/leisure
10.87
Dining: cafeteria/fast food
10.01
Dining: family
10.11
16
Task Group on
Lighting and Electrical Power (cont’d)
Lighting (cont’d)
 LPD tables updated
Lighting Power Densities Using the Building Method
Building Type(1)
Automotive facility
Lighting Power Density
(W/m2)
8.8
Convention centre
11.6
Courthouse
11.3
Dining: bar lounge/leisure
10.7
Dining: cafeteria/fast food
9.7
Dining: family
9.6
Dormitory
6.6
Exercise centre
9.5
Fire station
7.6
Gymnasium
10.8
Health-care clinic
9.4
Hospital
13.0
…
…
17
Task Group on
Lighting and Electrical Power (cont’d)
Lighting (cont’d)
 New lighting trade-off compliance path
• for interior lighting only
• quantify the impact of daylighting/daylight
dependent and other controls
• compare the overall lighting
energy use of a building to a
prescriptive baseline
18
Task Group on
Lighting and Electrical Power (cont’d)
Electrical Power
 Few technical changes are proposed
 New voltage drop
requirements for feeder
conductors and branch
circuit conductors
19
Task Group on
HVAC and Service Water Heating
 For prescriptive path, values for efficiency
ratings, insulation thicknesses, etc., are being
updated
 New requirements
• maximum temperature set
points for vestibules
• more requirements for when
cooling is installed
• more requirements for heat recovery systems
20
Task Group on
HVAC and Service Water Heating (cont’d)
 New HVAC and service water heating trade-off
compliance paths that consider system
efficiencies as opposed to individual component
efficiencies – would include losses through the
ducts and pipes
21
Task Group on
HVAC and Service Water Heating (cont’d)
Trade-off Path for HVAC (similar for SWH)
34

HVAC  TOI   1i   2i  ToVi   3i  ToVi
i 1
34

2

  1i   2i  BaVi   3i  BaVi
i 1
2

where
i - counter for number of components included, as per Article 5.3.2.2, for the given HVAC system
α1i - constant weighting factor to link the component efficiency variations of component i to system efficiency
variations as per Article 5.2.3.10
α2i - first order weighting factor to link the component efficiency variations of component i to system
efficiency variations as per Article 5.2.3.10
α3i - second order weighting factor to link the component efficiency variations of component i to system
efficiency variations as per Article 5.2.3.10
ToVi - Specified value of component i for the proposed building as per Article 5.3.2.5
BaVi - Base value specified for component i the reference building as per Article 5.3.2.6
22
Task Group on
Building Performance Compliance
 Contents of the supplement “Performance
Compliance for Buildings” is being shifted
to either the Code, the explanatory appendix
to the Code, or a proposed users guide
 Criteria/systems that are in the proposed
building will be included in the reference
building (e.g., cooling)
 The goal is to base compliance on building
energy targets – for a subsequent version of
the NECB
23
NECB 2011
 Public review of the proposed changes will
take place in the fall of 2010
www.nationalcodes.ca
24
NECB 2011
Questions?
25
www.nrc-cnrc.gc.ca/irc