The basis of a presentation built by Bfreehomes as a teaching tool for builders interested in understanding how to become a builder of Net Zero Energy Houses. Includes three case studies.

1. }
The Path to Net Zero
The Process of
Progressions
Current Practice
25% reduction
50% reduction
A Net Zero Energy House produces as much
energy as it uses on an annual basis.
This presentation focusses on how to get there.
75% reduction
Net Zero Energy

2. }
Focus of measures in progressions
Reductions most
cost-effective in
this order
Air tightness measures
Increase insulation
Water conservation
Mechanicals
Renewables

3. }
NRCan targets/goals for Industry
Capacity exceeds
code requirements
Issues
Concerns
Challenges
Innovations on the horizon

4. }
Energy Intensity
Energy Intensity vs.
House Size
Issues
Concerns
Challenges

5. }
Series of challenges
to reduce various
loads
Energy End Use Patterns
Lighting
5%
Appliances
13%
Water
17%
Space
65%
Lighting
6%
Space
57%
Appliances
16%
Water
21%
Reduce space heating load
Air tightness measures
Insulation Measures
Reduce water heating load
ERS80
(PRE-2012 R-2000)
Lighting
10%
Space
26%
Water
20%
Fixtures
ERS86
(conventional HVAC)
Drainwater Heat Recovery
Meeting DWH load becomes
biggest challenge
Net Zero Energy
(non-solar thermal)
Mechanicals designed around low
temp hot water delivery
Appliances
44%
Lighting
13%
Space
33%
Net Zero Energy
(solar thermal option)
Note: Ventilation included in ‘Space’ component in charts, ranges
from 2% of overall energy load in ERS80 to 9% in NZE
Small loads, can sacrifice efficiency
@ blower
Electrical base loads
Appliances
46%
Water
8%
Minimal electrical loads @ fans/
pumps
Primarily occupant driven
Builder has minimal impact

6. }
Energy Analysis & Financial Evaluation
Work Flow
Select target reduction
from baseline
Measures taken in initial
progressions impact the
types of measures (and
associated costs) further
down the path to Net Zero
Energy.
Model for 25%, 50%, 75%
and 100% reductions
from baseline
Select regionally appropriate
assemblies to increase
insulation levels
Specify high performance
mechanicals and renewables
Estimate regional fuel costs
Revisit, Revise,
Rethink
Excel
worksheet
Costings
Loads w/fuel equivalents
Energy contributions
Revise
to targets
IRR/
simple
payback
Incremental capital costs over baseline
Reductions in purchased fuel
Contributions from Renewables
Offsets to purchased fuel (DWHR)

7. }
Progressions
Ramping it up
ERS 80 (Existing
R2000)
ERS80↓25%
ESNH
• Performance Path, NSBC 2010, OBC 2012, NBC 2012
• NOTE: R2000 requires 1.5ACH @ 50Pa but ERS80 does not
• Air sealing: key for production builders – close in on 1.5 ACH
• Increase insulation -- Use exterior air barriers/rigid board ins. to help reduce ACH
• Higher efficiency conventional mechanicals (incl. HRV)
ERS80↓50%
R-2000
• Envelope: Further air sealing (1.0 ACH vs. 1.5 ACH), increase insulation, upgrade windows
• Hot water conservation – DWHR
• Higher efficiency, smaller space heating equipment
• Integrated mechanicals?
ERS80↓75%
• Last push @ envelope: emerging high-efficiency materials/windows
• Mechanicals: Integrated, renewables, match load, supply temps to delivery
• DHW is the load challenge
• Emerging technologies: air to water heat pumps, solar thermal concentrators, co-generation
Net Zero
Energy
• Choose mechanicals to reduce electrical loads as well as heating loads
• Reduce all possible electrical loading (LEDs, Energy Star appliances, motion detectors)
• Site-generated electricity production to match anticipated loads
Air sealing increasing
insulation highest priorities
for ERS80↓25%
ERS80↓50%
Mechanicals are the highest
priorities for ERS80↓75%
Renewables are the highest
priorities for NZE

8. }
Materials and Assemblies
Like standard
practice, only
better
Exterior insulation
Combinations
Fig. 1
Innovative materials
Assembly Issues
Brick ledge
Fig. 2
Fasteners
Window bucks details
Drainage plane
Construction Issues
Trades scheduling
Fig. 3
Inspectors

9. }
Materials and Assemblies
Like standard
practice, only
better
Tried True
Air sealing interior VDR
Insulating with foam or fibre
Innovative
Quad glass with 2 suspended
films, krypton fill
Vacuum Insulated panels:
RSI 22.7/mm (R30/inch)

10. }
Like standard
practice, only
better
Mechanicals
Hot
water
coil
Integrated systems
Space and water heating/cooling
Air
handler
Evaporator
Coil
(cooling)
optional
Space/water ventilation
Flexibility of energy sources
What types?
How many?
Issues
Integrated Space Conditioning
and Water Heating (forced air)
Preplanning
Servicing non-conventional systems
Distribution systems
Air to Water Heat Pump (hydronic
space conditioning and water heating)

11. }
Renewables
Always cheaper to
save a Watt than
make a Watt
Reduce loads
Space heating
Water heating
Lighting
Appliances
Builder can only supply a
house than can approach
net zero energy
Energy usage dependent on
occupant lifestyle
Preplanning
Solar thermal
PV
Micro co-generation
District energy

12. }
Regional Differences
What works in
different areas
Assemblies materials
Mechanicals
Airtightness
Labour/Trades
Fuel Costs/Perceptions

13. }
Builder Type – Economies of Scale
Large/Mid-size
Production
or Custom
Scheduling issues
Labour/training issues
Client interaction
Market Dynamics

14. Financial Valuation of Premiums
Simple Payback:
the point on the graph where
the cost of the investment is
recovered. Expressed in years
or months
Capital Expenditure
Years after capital expenditure
Internal Rate of Return:
All cash flows (+/-)
}
the point on the graph where the costs
of the investment equal the benefits of
the investment. Expressed as a
percentage that represents how well
your investment is working for you
each year after you have taken care of
all of your costs.
Internal Rate of
Return vs. Payback
What is Payback
• The time required for the
return on an investment
to “repay” the sum of the
original investment.
What is Internal Rate of
Return (IRR)?
• Tells you how well your
money is working for you
compared to other
investments or costs of
borrowing.
•
Indicator of the efficiency,
quality or yield of an
Planning Horizon (years)
investment.

15. }
Communicating IRR to the Client
Perceptions of
Costs
Simple Payback:
“The quicker the better”
vs.
long-term investment
How to talk about IRR?
costs
benefits
• IRR
of 10% over 10 years for
NZE construction/mechanicals can
be compared to interest on the
increased mortgage principal
needed for the premium to be
paid over and above the baseline
construction and mechanicals

16. }
2-storey w/
basement
ERS80 Baseline
ESNH/R-2000 Upgrade Package (Ottawa)
12
House Characteristics
10
325 m2 (3,500 s.f.) living space
12
4
2 storey house + finished
basement
15% glazing
A5
HOUSE 3 FRONT ELEVATION
ID
Library Part Na...
Quantity
W x H Size
2D Symbol
1:64
A5
Door Legend
D1 10 D1 Entrance 10 D1 Entrance 10 D1 Garage 1 10
5
1
1
1
0.813x2.000
1.067x2.100
1.219x2.100
3.048x2.134
HOUSE 3 REAR ELEVATION
D1 Pocket 10
1
0.762x2.100
1:64
Attached garage
D2 10
1
1.800x2.100
Conventional mechanicals
12
10
3D Front View
A5
HOUSE 3 DOOR SCHEDULE
1:1
12
4
A5
HOUSE 3 FRONT ELEVATION
ID
Library Part Na...
Quantity
W x H Size
2D Symbol
1:64
A5
Door Legend
D1 10 D1 Entrance 10 D1 Entrance 10 D1 Garage 1 10
5
1
1
1
0.813x2.000
1.067x2.100
1.219x2.100
3.048x2.134
HOUSE 3 REAR ELEVATION
D1 Pocket 10
1
0.762x2.100
D2 10
1
1.800x2.100
3D Front View
A5
HOUSE 3 DOOR SCHEDULE
1:1
1:64

17. }
ESNH/R-2000 Upgrade Package (Ottawa)
2-storey w/
basement
ERS80 Baseline
Total heated space = 3,500 s.f.
HOUSE 3
5.11
HOUSE 3
•
•
BELOW-GRADE
WALLS:
RSI 2.1/R12 fibreglass batt
interior standoff wall
•
ABOVE-GRADE
WALLS:
RSI 3.9/R22 fibreglass batt
•
98
2.93
ATTIC:
RSI 8.8/R50 blown cellulose
BELOW SLAB:
RSI 1.8/R10
WINDOWS:
Low-e, argon-filled, insulating
spacers, vinyl frames
8.60
8.88
BEDROOM
Air tightness: 4.55 ACH
•
2.42
BEDROOM
2.42
INTERIOR AREA:
41.538 m2
BEDROOM
4.83
2.09
38mm x 140mm framing @
400mm O.C. drywall
46
HOUSE 3
HOUSE 3
5.72
HOUSE 3
HOUSE 3
3.17
5'-11 by 6'-11
1:64
38mm x 140mm framing @
400mm O.C. drywall
2.89
2.95
3'-6
6'-11
61
2'-8 by 6'-7
13
13
12
12
8
7
6
5
5
4
4
3
3
2
2
1
1
GARAGE
9'1 CEILING
HEIGHT
5.64
6
9.49
9
8
8.60
9
3'by 6'
11
10
7
8.88
11
10
11.13
3.84
KITCHEN
INTERIOR AREA:
48.9119 m2
3'by 6'
LIVING
38 mmx235mm floor joists @ 400mm
O.C. 18.5mm TG plywood
4.83
10' by 7'
45
4'
6'-11
1.65
1.65
2.31
1.65
1.27
2.59
1.26
4.27
5.11
HOUSE 3
HOUSE 3
HOUSE 3
•
1:64
HOUSE 3
WATER HEATING:
67% AFUE 60 gal tank
VENTILATION:
60% sensible efficiency
61
3.66
SPACE HEATING:
92% AFUE gas furnace
•
61
•
•
HOUSE 3
5.11
SLAB ON GRADE
W
LAUNDRY
13
12
11
10
9
8
8.88
INTERIOR AREA:
37.5537m 2
7
6
FINISHED
SLAB ON
GRADE
5
4
3
2
1
38 mmx235mm floor joists @ 400mm
O.C. 18.5mm TG plywood
4.53
UNEXCAVATED
1.65
HOUSE 3 MAIN FLOOR
8.29
A2
8.88
HOUSE 3 UPPER FLOOR PLAN
F
A3
HOUSE 3
61
61
2.56
5.11
4.27
FINISHED BASEMENT
AREA: 45.3768 m2
HOUSE 3
HOUSE 3
HOUSE 3
A1
HOUSE 3 FOUNDATION
1:64

18. }
ESNH (ERS80↓25%) Package, Ottawa
Measure
RSI 10.6/R60 attic
RSI 6.3/R32 above grade walls
RSI 3.9/R22 below grade walls
86% AFUE Instantaneous gas
DHW
75% Efficient HRV
DWHR
Upgrade
Cost
GJ saved
$540
$6815
$818
46.47 GJ
Changes
from ERS80
ESNH Envelope
(ERS80↓25%):
•
Air tightness: 2.0 ACH
7.90 GJ
•
ATTIC:
RSI 10.6/R60 blown cellulose
$300
-1.82 GJ
•
$500
2.63 GJ
ABOVE-GRADE WALLS:
RSI 3.9/R22 fibreglass batt plus
2” Type IV exterior
(or 1.5” polyisocyanurate)
10” fdn wall for brick siding
•
BELOW-GRADE WALLS:
RSI 3.9/R22 fibreglass batt
interior standoff wall
•
BELOW SLAB:
RSI 1.8/R10,
no change from baseline
Rental vs. $1100

19. }
R-2000 (ERS80↓50%) Package, Ottawa
Measure
RSI 10.6/R60 attic
RSI 7.0/R40 above grade walls
RSI 4.9/R28 below grade walls
86% AFUE Instantaneous gas
DHW
Upgrade
Cost
GJ saved
$540
$15744
$2314
63.99 GJ
Changes
from ERS80
R2000 Envelope
(ERS80↓50%):
DWHR
7.90 GJ
$300
-1.82 GJ
$500
AIR TIGHTNESS: 1.0 ACH
•
ATTIC:
RSI 10.6/R60 blown cellulose
•
ABOVE-GRADE WALLS:
RSI 3.9/R22 fibreglass batt plus
2.5” polyisocyanurate
10” fdn wall for brick siding
•
75% Efficient HRV
Rental vs. $1100
•
BELOW-GRADE WALLS:
RSI 3.9/R22 fibreglass batt
interior standoff wall plus
1.5” Type IV exterior
•
BELOW SLAB:
RSI 1.8/R10,
no change from baseline
2.63 GJ
Main upgrades from ESNH (ERS80↓25%):
Air tightness from 2.0 to 1.0
Below Grade Walls from RSI 3.9/R22 to RSI 4.9/R28
Above Grade Walls from RSI 6.3/R32 to RSI 7.0/R40

20. }
ESNH/R-2000 Upgrade Package (Ottawa)
ERS 80
ESNH
Reductions
from ERS80
Space heating
R-2000
•
•
Space
heating
108.41 GJ
Water
heating
23.92 GJ
Base loads
31.53 GJ
61.93 GJ
44.42 GJ
•
ERS80: 94% gas furnace ( AFUE)
ESNH: no change from baseline
R-2000: no change from baseline
Water heating
16.01 GJ
15.99 GJ
•
•
•
31.53 GJ
31.53 GJ
ERS80: .67 AFUE gas (tank)
ESNH: instantaneous gas water
heater 0.86 EF
R-2000: instantaneous gas water
heater 0.92 EF
Hot water load reduced by:
ACH@50Pa
4.55
2.0
1.0
•
•
ESNH: 33.05%
ERS86: 33.15%
Ventilation
•
•
•
ERS80: 60% EF HRV
ESNH: 75% EF HRV
R-2000: 75% EF HRV

21. }
ESNH/R-2000 Upgrade Package (Ottawa)
Estimated Median Cost Increase of Progression for
ERS80↓25% (ESNH)!
$12,000
Reductions
from ERS80
Cost increase
•
ESNH – 25%
$10,000
•
Envelope - $8,173
$6,000
•
Mechanicals - $1,900
$4,000
•
Package - $10,073
$8,000
$2,000
•
$0
Vancouver Kamloops
GTA
Ottawa
Sudbury Nova Scotia
R-2000 – 50%
•
•
Mechanicals - $1,900
•
Estimated Median Cost Increase of Progression for
ERS80↓50% (R-2000)!
Envelope - $18,598
Package - $20,498
$25,000
IRR/Simple Payback – 10
years with annualized capital
costs over the 10 years
$20,000
$15,000
$10,000
•
$5,000
$0
Vancouver Kamloops
GTA
Ottawa
Sudbury Nova Scotia
ESNH - none
•
R2000 - none

22. }
Denim Homes/Nova Scotia Power
Demonstration House: ERS96
ERS80↓75%
House Characteristics
214 m2 (2,300 s.f.) living space
2-storey slab-on-grade
No garage
3.76kW p Photovoltaics (PV)
(16 * 235W modules)
4 flat-plate solar thermal
collectors

23. }
Denim Homes/Nova Scotia Power
Demonstration House: ERS96
ERS80↓75%
Final ERS = 96
Measure
ERS
Mechanicals
•
Air-to-Air heat pump
(primary heating
cooling)
•
Solar thermal and two
drainwater heat
recovery (DWHR) units
•
Radiant heating system
in floor is fed by excess
from DWHR and two
solar thermal collectors
Total heated space = 2,300 s.f.
80
Improved Envelope
Renewables
96
This house features selective glazing.
The south and west facing windows are double-pane
units to take advantage of passive solar gain.
The north facing windows, which don’t contribute to
solar gain, are triple-pane units.
ATTIC:
RSI 10.6/R60 blown cellulose
•
ABOVE-GRADE WALLS:
RSI 7.4/R42 wet sprayed
cellulose 75mm (1.5 inches)
rigid board
•
BELOW SLAB:
RSI 4.4/R25 Type III
•
WINDOWS:
Low-e, argon-filled, insulating
spacers, vinyl frames,
•
Benchmark (NS Code)
•
SPACE CONDITIONING:
Air-Source Heat Pump,
with Solar Thermal in-floor
•
WATER HEATING:
Solar, DWHR, electric boost
•
VENTILATION:
•
High efficiency HRV

24. }
Denim Homes/Nova Scotia Power
Demonstration House: ERS96
ERS80↓75%
Wall Detail
Double 2x4 stud wall on 2x10 plate
Fibre-cement siding
3/8” vertical PT lath @
800mm (24”) o.c. (rainscreen)
Housewrap
7/16” sheathing
Double 2x4 staggered stud walls @ 800mm (24”)
o.c. on 2x10 plates
RSI6.3/R36 wet-spray cellulose
RSI 1.3/R7.5 foil-faced rigid insulation
Drywall, taped and sealed
Staggering eliminates thermal
bridging
Rainscreen detail
Foil-faced rigid board to interior
provides air barrier
Wet-spray cellulose stays in place,
can have higher density, higher
R-value per unit thickness
Headers are filled with RSI 7/R40
high-density spray foam
Staggered Double Stud
Wall, Corner Detail

25. }
BC Green Dream Home
Getting to Net
Zero Energy
House Characteristics
301m2 (3,237 s.f.)
2storey with walkout
basement
Attached garage
8.3 kWp Photovoltaics (PV)
(36 * 190W modules)
(8 * 190W modules)
2 evacuated tube solar
thermal collectors

26. }
BC Green Dream Home
Measure
Benchmark (Envelope)
Getting to Net
Zero Energy
ERS
Estimated MJ
85
90,390
Thermal Envelope = ERS85
38,265
Improved Mechanicals
Renewables
House Characteristics
101
Ceiling RSI 10.6 (R-60)
(6,720)
Foundation walls RSI 7.5 (R-44)
Main walls RSI 7.5 (R-44)
Slab RSI 3.5 (R-20)
Windows
3-pane, low-E 10 (soft coat),
13mm argon fill, insulating
spacers, vinyl frames
Attic Insulation:
75mm (3 inches) urethane foam
400mm (16 inches) blown cellulose
Footing to Rafter
ICF construction:
Total 273mm (10 ¾ inches) foam
0.68 ACH@50Pa
(0.5ACH target)
Mechanicals
Space heating: Geothermal
Water Heating Solar DHW + HP
preheat, DWHR, secondary
electric boost as required
Ventilation: HRV
Space Cooling: Geothermal

27. }
BC Green Dream Home
Getting to Net
Zero Energy
Geothermal (5.1 COP per
Secondary
Solar Water Heating System
manufacturer) feeds space
heating and pre-heats DHW
Solar thermal and drainwater
heat recovery (DWHR) unit
reduce hot water load
Secondary electric tank boosts
DHW
Annual DHW energy
Primary
Drainwater Heat Recovery
requirement = 4000 kWh
Solar contributes 2100 kWh-e
Geothermal Heat Pump
Desuperheater
DWHR contributes 460 kWh-e
Solar
DHW
Array

28. }
BC Green Dream Home
Getting to Net
Zero Energy
Electrical load
Lighting, appliances, electronics, exterior
Solar
DHW
Array
6.8 kW Roof Mounted
Array
CMHC default: 24 kWh/day
Actual Load: 11.5 kWh/day
PV: 8.3 kWpeak capacity
Modelled energy production
9940 kWh/yr
Monitored energy production
(Jun-Sep 2010) = -0.4% under
1.5 kW Bi-Facial Balcony
Array
model

29. }
BC Green Dream Home
Getting to Net
Zero Energy
PV optimized by using
shadow modelling to
determine array placement
and ‘string’ arrangement.
Innovative ‘bi-facial’ PV
panels used in vertical
installation as balcony guard.
1
4
1 1 1 1 1 1 X 1 4X 4 4
X3
1 2 2 2 3 3
4 4 4
2 2 2 3 3
4 4
X
2 2 3 3
2 3 3 Strings 1 2 è (18 modules) Inverter 1
All energy used and
produced is monitored.
Strings 3 4 è (18 modules) Inverter 2
Photo courtesy:
www.greendreamhome.ca

30. }
BC Green Dream Home
Getting to Net
Zero Energy
33% Cost Increase over
ERS80 baseline:
Envelope: $40,000
Mechanicals $10,000
PV: $50,000
Package: $100,000
Finish package = $200,000
Construction Cost = $600,000
Land cost = $150,000
ROI/payback unknown
Photos courtesy: www.greendreamhome.ca