Net Zero Energy on the Canadian Prairies

1. Net Zero Energy on the Canadian Prairies

2. Habitat Studio has built
over 40 houses with
Energuide Ratings of 86 or
better
Our minimum energy
specification results in a
Energuide rating of 82

3. Net Zero Energy
• Produces all of its own energy for
Heating, DHW, Lighting and
Appliances, on site, over the course
of a year.
• Next to impossible without high
levels of energy conservation
!

4. • Conservation is the simplest, most economical and most
reliable route to energy and greenhouse gas reduction -
better than solar PV, solar hot water, better than
geothermal
• Without aggressive conservation there’s not much point in
planning for renewable energy collection
• The most benign energy available is the energy you don’t
ever need.
Building a Better Building Envelope
• Very hard to fix the
building envelope later

5. CANADA MORTGAGE AND HOUSING CORPORATION!
Riverdale NetZero Project — Edmonton, AB
Project Team
Habitat Studio & Workshop Ltd. and Howell-Mayhew Engineering

6. CANADA MORTGAGE AND HOUSING CORPORATION!
EQuilibriumTM Housing Demonstration Projects

7. • 54000 C Heating
Degree Days
• -340 C DesignTemp
Habitat Studio NetZero Energy Houses so far
Riverdale NetZero
Mill Creek NetZero
Belgravia NetZero Parkland NetZero
South Windsor Park
NetZero Holyrood Near
NetZero Retrofit
Edmonton
Winnipeg
• 59000 C Heating
Degree Days
• -350 C DesignTemp

8. Habitat Studio Net Zero houses this year
Allen Residence
Shute Salvalaggio Residence Kennepohl Franchuk Residence
Kosowan Ferrero Residence

9. Belgravia NetZero
• 1900 sq. ft. with basement suite (TFA 1981sqft /184 m2 ),
currently one occupant
• Excellent solar site
• 7740 watts of PV- 5160 watts moveable, 2580 watts fixed
• 12.6% south glazing area, 2 1/2” concrete on floors
• Dead simple, very low cost electric baseboard heaters and
DHW
• Incremental investment in conservation was partially paid for by
savings on the mechanical system
• Has used ~5600kWh/a for heating, lighting, appliances, and
DHW and generated 9600 kWh- a 4000 kWh surplus for two
years in a row. (30kWh/m2 all in).

10. • Panelized factory built
2x8 Filled with 5" 2lb
Spray foam & 2.25"
fibreglass
• East west facing site
• Air source heat pump
heating
• Air source heat pump
hot water
• 16.3 kW photovoltaic
system
• Landmark builds over
1000 homes per year
Landmark Group of Builders Ltd.

12. Effect Home Builders
Belgravia Green Net Zero Energy Home
• ~1600 sqft bungalow with finished
basement
• partially shaded south facing site
• Air source heat pump
• Electric demand hot water
• 12.5 kW photovoltaic system

13. Star Prebuilt Homes Ltd

14. NRCan R2000 Net Zero Energy Pilot
• 13 projects representing all regions of the country
• Intended to demonstrate and prove the lessons learned following the CHMC
Equilibrium Housing Initiative.
• Will test drive NRCan’s new Energuide Rating System and provide empirical
support for Net Zero and Net Zero Ready labels that will be issued as part of the
new R2000 program.
• The new R2000 standard comes in at ~EGH 86 which can get you to net zero
with a reasonable amount of PV.
Key differences
• A nifty spreadsheet for calculating new ERS numbers and verifying net
zero energy compliance.
• Simpler systems - fewer science experiments
• Air source heat pumps for heating and hot water.
• Net Zero Energy houses on sites with poor solar exposure.

15. “CHBA’s Net Zero Energy Housing Council (NZC) supports innovation in our industry with
the goal of creating a market advantage for CHBA builder and renovator members who choose
to pursue it.This will not only help to meet the housing aspirations of Canadians, but renew
Canadian world leadership in high performance housing.”
In#alignment#with#the#CHBA#Strategic#Priority#to#Advance(Innova+on,#the#
mandate#of#this#self;funding#ad;hoc#Council#is#to(deliver(services(that(
will(support(members’(voluntary(adop+on(of(NZE.(
#
The#NZC#will:#
! gather#intelligence#on#member#and#consumer#needs#to#inform#prioriCes#and#
influence#strategic#advancements,#
! build#awareness#and#knowledge#through#the#consolidaCon#and#sharing#of#
informaCon#uClizing#a#variety#of#channels#and#forums,#and#
! implement#acCviCes#to#idenCfy#barriers,#find#soluCons,#transfer#knowledge,#inform#
policy,#accelerate#acCon#and#increase#efficiencies.##
CHBC$Net$Zero$Energy$Council$$

16. • Started in Canada and now North America wide
• Great webinars at http://netzeroenergycoalition.com/connect/
webinars/
• Net zero energy housing is thriving in the US-especially California
where it will be a requirement in 2020.
• A number of small US builders making a good business out of
doing mostly net zero energy housing
• Some America’s biggest home builders -Pulte Homes,Toll Brothers,
Meritage, KB Homes are all delivering NZ homes.
• US DOE Zero Energy Ready Homes- great source of info on how
to build and sell NZ houses.
“Zero
energy-­‐ready
homes
are
the
future
of
American
housing.
They
have
to
be.
They
live
be;er,
help
to
protect
health
provide
luxurious
comfort,
work
be;er,
and
last
be;er
because
of
lower
maintenance
and
forward-­‐looking
construcAon
that
can
help
ensure
future
value.”
-­‐Sam
Rashkin,
Chief
Architect
of
the
Building
Technologies
Office,
US
Department
of
Energy

17. 63 | INNOVATION & INTEGRATION: Transforming the Energy Efficiency Market Buildings.Energy.gov
Lasts
Better
Works
Better
Lives
Better
Advanced
Technology
Ultra-Low
Utility Bills
Engineered
Comfort
Healthier
Living
Quality
Construction
More
Durability
Black-Out
Power
Water
Efficient
Solar
Ready
Long-Term
Warranty
Disaster
Resistant
Lower Cost
Insur./Mort.
Zero Energy Ready Home Value

18. Other Benefits
• Market differentiation
• Makes you a better builder. Your houses will
be
•More comfortable
•Healthier
•More durable
• It is worth getting in on the ground floor -
This is likely coming anyway.
• Trust factor

19. Net Zero in 10 easy steps
• Model the energy performance of your
preliminary design
• Use the modelling results to optimize
the building envelope and passive solar
gain
• Reduce base loads
• Domestic hot water
• Lighting and appliances
!
• Evaluate air source heat pumps or
geothermal and other renewables
• Size PV to meet remaining total load
Energy Reduction
Renewable Energy Collection
• Site assessment
• Preliminary design
• Optimize passive solar if available
• Finish detailed architectural and system
design

20. Preliminary Design
• Usual home design considerations- Job #1 is to
build a great place to live.
• Keep living spaces on the south side to make best
use of passive solar potential
• Try to accommodate space for PV generation
• Keep the shape simple and compact

21. Site
Assessment
• Evaluate the Solar Potential
• Consider potential shading from buildings, trees, etc.
• Potential for renewable energy collection
• Passive solar is not often available on urban lots, but when it is, it makes
net zero a lot easier.
S
January 15

22. House Shape
• Smaller buildings use less total energy and are cheaper to build
• Bigger houses often use less energy per square foot but more
energy in total
• Simpler shapes have less surface area.
• Buildings with big cathedral ceilings and lots of dormers have more
surface area
• Making small simple buildings look great can be a challenge

23. Providing room for renewable energy collection:As PV gets cheaper,
finding roof space becomes the limiting factor
Riverdale NetZero
Mill Creek NetZero
Bonnie Doon NetZero
Parkland NetZero
Windsor Park NetZero
NRCan NZ Pilot

24. 19°
53°
885 square feet
375 square feet
Roof shape and orientation
• When PV costs were $6.00 to $7.00 per installed peak watt we
angled the roof to get as much output as possible from each
module.
• Now with PV costing $3 to $3.50 per installed peak watt it makes
more sense to accommodate as many modules as possible and
accept lower output per module.

25. Modelling
• Good modelling is everything. Designing for net
zero at an optimum cost is almost impossible
without it. You're shooting in the dark
• Model early in the design process while it is still
easy to make changes and before people get
attached to particular configurations
• Model in house if possible, but if you can’t you
can still learn a lot by playing with the input
values in a model set up an expert evaluator.
• It seems like a lot of work, but can be done in a
couple of hours after you’ve done it a few
times.

26. ModellingTools
• HOT2000 is tested, tried, and true. It is the basis for most
Canadian labelling and rebate programs
• Passive House Planning Package (PHPP) is excellent. It gives
very detailed feedback and lets you dial in the important details

27. Using modelling to optimize the cost of
conservation measures
For Net Zero Energy at the Lowest Cost
Cost per kWh/year of energy
collection*=
Cost per kWh/year of energy
conservation
Cost per kilowatt-hour/year (kWh/a) of any
energy conservation measure
Cost of the measure divided by energy
saving in kilowatt-hours per year(kWh/a)
=
*Current cost of PV in Edmonton is $3.00
to $3.50 for the capacity to generate
1 kWh/year
N.B.This works until you run out of roof space and it ignores the fact that
there are primary energy consequences to exporting large amounts of energy
to the grid in summer and drawing it back in winter

28. Envelope Modelling/Optimization
• Determine Current PV cost or other benchmark energy price.
• Evaluate envelope upgrades with respect to cost per kWh/year of energy
saved.
• Optimize envelope specifications: foundation,walls, roof, windows, air tightness.
• Extra conservation cost can often be offset by simpler mechanical systems

29. Options for walls with better performance than
2x6 16” O.C.
• 2x6 @ 24” O.C. (R 17.9 vs R16.5)
• 2x6 or 2x8 with high density foam -
• ICFs (Insulated Concrete Forms)
• SIPs (Structurally Insulated Panels
• 2x6 with 2x3 Strapping
• 2x8 24” O.C. with OVE details
• Double 2x4 walls - 10” to 16” thick
• Saskatchewan Double 2x4 wall
• 2x4 with Larsen trusses
• 2x6 with exterior rigid insulation foam or
rigid Roxul-
• REMOTE walls - see CCHRC site for
some great pamphlets

30. Considerations in choosing a wall system
• Lowest cost per effective R value
• Ease of getting ultra air tightness.
• Continuous insulation layer- no thermal thermal bridges
• Durability- vapour openness.
• Ease of construction
• not too disruptive of normal construction sequence
• minimal work from scaffolding

31. High Density Spray Foam in a 2x6 wall
• R 24.8 (effective) for 2x6 24”
O.C
• Less fussy
• Less labour
• Use less space
• Good air tightness with some
remedial sealing
!
+
!
-
• Expensive
• No thermal break
• High embodied energy
• Less environmentally friendly- high
GHG emissions from blowing
agents
• Hard to renovate
• Not good for some small gaps
• Not as air tight as you would think

32. Riverdale Deep Wall
!
• Lowest incremental cost to get
R40+
• Follows normal construction
sequence
• Can be very air tight
• Versatile
• Almost the same amount of
dimension lumber as standard
2x6 @ 16” O.C.
• Minimal Waste
!
+
• Extra labour
• Fussy air sealing
• Takes extra space
• Hard to renovate
!
-

33. Frost Wall Insulation
• 20 to 30% of total house heat
loss can be from the
basement.
• Basement walls should have
almost as high R value as
upper walls
• Very hard to add later
This thermal break has a great payback
4" of Type 2 EPS
Drainage layer for any condensation
'Smart' vapour barrier

34. • Air tightness is by far the cheapest energy
reduction investment you can make
• Air test results of 0.6ACH 50 or better are
achievable in wood frame buildings.
• Keeping uncontrolled air leakage out wall
assemblies enhances durability
• New vapour open air sealing products and
techniques are one of the biggest benefits of the
Passive House approach.

35. Draw an uninterrupted line around
the entire thermal envelope.

36. Passive buildings need to have
low thermal bridging.
• Both Construction Thermal
Bridges and Geometric Thermal
Bridges can be significant.
• At some point piling more
insulation onto the surfaces
doesn’t help much, and the joints
and points need to be looked at.
©Passive House Institute US 2013 – Certified Passive House Consultant Training
and points need to be looked at.
7
Picture Credit: David White

37. Thermal Bridging Control
• HOT2000 is responsive to thermal bridging control is a few
areas, but isn’t transparent.
• Effective R values depend on continuous insulation layers.
• Passive House Planning Package (PHPP) requires detailed
input and gives good feedback on the consequences of
thermal bridging.
• Eliminating thermal bridging will reduce heat loss
substantially whether you can calculate it or not.

38. Windows
Courtesy of the US DOE
Windows and doors are the single biggest source of transmission
heat loss - often 40% or more of the total building heat loss.

39. Window Shopping- features to look for
• Low conductivity (Low U value/high R
value) glass
• High solar heat gain coefficient (on the
south)
• Low conductivity (Low U value/high R
value) frames
• Slim profile frames- typically the glass will
have a better U value than the frame
• Low conductivity spacer bars
• Good airtightness- preferably triple weather
stripping
• Durable
• A few large windows (less frame and
framing) will use less energy and cost less
than more small windows of the same total
area.

40. Heat RecoveryVentilators
• Any air tight building requires a
continuous supply of fresh air.
Heating ventilation air can require up
to 20% of the total heating energy
• HRV’s are an essential component of
high performance housing
• Most HRV’s have relatively low
efficiency. ( ~55 to 65%)
• High efficiency HRV’s (80 to 95%)
are a good investment and have a
short payback.

41. Total Annual Heating Energy Reduction(kWh/year)
Domestic Water Heating
Cooling
Lighting and Appliances
*Net Annual space Heating
*Including passive solar and internal gains and heat pump C.O.P.

42. • Low flow shower heads
• Efficient Hot WaterTanks
• Water conserving dishwasher
• Water conserving clothes washer
• Grey water heat recovery
Domestic Hot-Water Energy
Reduction

43. • Energy Efficient Appliances
• refrigerator
• clothes washer
• No Dryer
• Range/ Pressure cooker
• Energy Efficient Lighting
• compact fluorescents
• LEDs
• task lighting
• day lighting
• Energy Efficient Motors
• ventilation
• heating
• Phantom Load Control
• The Energy Detective(TED)
monitor
Electrical Load Reduction

44. Riverdale NZ Heating Schematic
SolarThermal Space Heating
7- Zen 28S Collectors
• Can be very expensive if you size to meet a high
percentage of the winter load.
• Not enough energy available when you need it most
• Can be very complicated
• Potential to harvest more useful energy per sq. ft than
PV (~20 kWh/sq.ft./year)
• Incremental cost at Riverdale~ $50000 per unit
Fresh Air
from
Outdoors
Exhaust
Air to
Outdoors
Exhaust Air from
Bathrooms &
Kitchen
Return Air
from
House
Fan Coil
Heated / Cooled
Air to House
7 Solar
Heating
Collectors
Domestic
Hot Water
Domestic
Cold Water
from Mains
Drain
Water Heat
Recovery
Electric
Heating
Element
Fan Coil
Pump
2 T
Heat
Pump
Ground Loops
GL1. 41 m under garage
GL2. 55 m around foundation
Daily Heat Storage Tank
Seasonal Heat Storage Tank
Tempering Valve
17,000 litres
water
300 litres
water
Cold Water
to Interior
Uses
Heat
Recovery
Ventilator
Fan
Fan
Dwg M1. Riverdale NetZero House Mechanical Systems Layout
ver 3d Drawn and developed by: David Morrow, Hydraft Development Services
Peter Amerongen, Habitat Studio and Workshop
Monitoring Instrumentation: Gordon Howell, Howell-Mayhew Engineering
Date: 2008 August 02
55°C to
80°C
5°C to 90°C
6 GJ of heat
Fresh Air
to House
Fan
Daily Storage
Tank Bypass
Valves
Fan Coil
Bypass
Valves
Seasonal
Storage Tank
Bypass
Valves
Drainback
Tank
30 litres
water
Surface
area:
21 m2
Cold Water
to Exterior
Uses
WM-cmWM-dh
Tsolar-in Tsolar-out
Tfc-in
Tfc-out
T1
T3
T4
T5
T8
House
Temperature
Outdoor
Temperature
T6
a
b V1
HX3
HX2
HX1
E1
V3
a
V4 a
b
V5
b
a
V7
a
b
V6 a
b
P2
F1
F2
F3
Fsolar
Ffc
HX4
Tempered
Water to
Showers
WM-cx
Solar
Collector
Pump
P1
Solar Supply
Heat Meter
HM-ss
a V2
b
Vent
T2
c
V8
a
b
c
GL1
Daily
Storage
Tank
Bypass
Valves
Seasonal
Storage
Tank
Bypass
Valves
GL2
Heat Pump
Pump
Fan Coil
Heat Meter
HM-fc
b
Heat from solar collectors
Solar heat to daily tank
Solar heat to seasonal tank
Potable water
Stored heat from seasonal tank
Stored heat to fan coil
Stored heat to daily tank
Stored heat to heat pump
Concentrated heat from heat pump
Heat to/from ground loops
Cold Water
Pre-Heat
HX5
T7
Colour Legend
for Heating Loops:
P3
Nearest Nuclear
Fusion Furnace
Notes:
1. Ground loops intended to provide space cooling only.
2. Heat pump supplements the moving of heat if
required:
a) from seasonal tank to fan coil by taking the
seasonal tank from 25°C down to 5°C;
b) from seasonal tank to daily tank; and
c) from fan coil to ground loops for space cooling.
3. Manual valve sets V7 and V8
a) “a” is mainly used to create backpressure so loop
remains pressured while serving the
non-pressurised tank;
b) “a” & “b” are used for seasonal selection of ground
loops for cooling;
c) “c” is for isolation only – it is normally open.

45. Net Zero in 10 kind of easy steps
• Model the energy performance of your
preliminary design
• Use the modelling results to optimize
the building envelope and passive solar
gain
• Reduce base loads
• Domestic hot water
• Lighting and appliances
!
• Consider Air Source Heat Pumps or
Geothermal
• Size PV to meet remaining total load
Energy Reduction
Renewable Energy Collection
• Site assessment
• Preliminary design
• Optimize passive solar if available
• Finish detailed architectural and system
design

46. • The energy harvested by Air
Source Heat Pumps is 100%
renewable - solar energy with no
direct sun.
• It is possible to get C.O.P.’s* of 2 or
better in Edmonton or Winnipeg.
• C.O.P. drops off as temperature get
colder.
• Mitsubishi ‘Hyperheat’ units have
shown C.O.P.’s of greater than 1.0
at temperatures as low as -30℃
• They can make or break the
attempt to get to net zero energy.
0"
5"
10"
15"
20"
25"
30"
35"
40"
45"
50"
1"
13"
25"
37"
49"
61"
73"
85"
97"
109"
121"
133"
145"
157"
169"
181"
193"
205"
217"
229"
241"
253"
265"
277"
289"
301"
313"
325"
337"
349"
361"
Series1"
Edmonton Heating Degree Days 2013
Mitsubishi ‘Hyperheat’ cutoff (~-25℃)
*C.O.P. - Coefficient of Performance
C.O.P. of 2 indicates 2 units of energy out for
every 1 unit of electricity in.
Air Source Heat Pump operating range

47. Heating and ventilating with a small mini split air source heat pump
*Needs EGH 86 or
better envelope
Mini split outdoor unit
Fresh air from
outside
Fresh air to house
Exhaust stale air out
Mini split indoor
unit c/w blower
Stale air exhaust
from kitchen,
bathrooms
and laundry
Transition
supply duct
Controller to sync mini split fan
with thermostat and post heater
10kW Thermolec
Post Heater
HRV
12" round duct to
supply heating and
fresh air to house.
500CFM at
< 0.36 in.WG
12 " return air from house

48. Mini splits vs Central systems
• Ductless mini splits can save heating
system dollars if the loads are small
enough to be met with point source
heating and electric baseboard back up.
• Big central ASHP’s like the Mitsubishi
Zuba Central will add ~$8000 to
heating system costs.
• Even at that price central systems can
pay for themselves in offset PV costs.
For example, if it saves 3000kWh/year
if will offset $10,500 worth of PV and
also need less roof space.

49. Air Source Heat Pumps for Domestic Hot Water
• Relatively low cost $1500-2000
• Provide a small summer cooling
benefit
• Work well in tandem with Air
Source Heat Pump or
Geothermal heating.
• Will shrink the size of the PV
array
• Annual COP of ~1.50 to1.75 is
possible
• Provides a small amount of
summer cooling
!
+
!
- • Will increase winter heating load
• Noisy

50. Photovoltaic Electricity (PV)
!
• Requires lots of roof space- 100 sq.
ft. to generate 1500 kWh/ year -
more if you have shading
• Expensive ~ $3.00 to $3.50 per
installed watt of peak capacity.Typical
NZ system $30,000 to $40,000(Each
installed watt in Edmonton will
produce 1.1 kWh per year.)
• Supply is out of sync with demand -
grid dependant.
!
• Very simple installation, durable, almost no
maintenance
• Can be added later if roof space is available
• With grid tie it doesn’t matter that supply and
demand are out of sync.
• “PV is a rock the makes electricity” Martin
Holladay
!
+
!
-

51. Envelope Specifications
Foundation
R25- 2" EPS +R20 frost
wall
R37- 4"EPS + R22 Frost
wall
R52- 6" EPS + R28 Frost
wall
underlab insulation R9- 2" Type 2 EPS R18- 4" Type 2 EPS R27
Walls
R 24 - 2x8, 24"O.C. R28
Batt
R40- 12" Double 2x4 ,
24" OC
R67- 16" Double 2x4with
2x4 wiring chase,
Cellulose plus R14 roxul
Ceiling R60- cellulose R80 - cellulose R100- cellulose
Windows
Duxton fbreglass wih
R5.33/R8.33 COG
Duxton fbreglass wih
R5.33/R8.33 COG
~R 10 COG Passive House
windows
Air tighness
1.5 ACH -Caulked poly
with Habitat details
.5 ACH - Caulked Poly
with Siga tape and extra
care and attention
.03 ACH- Taped OSB,
even more care and
attention, Passive house
windows
Mechanical Systems
Heating system
Large central air source
heat pump- Zuba Central
Ducted mini split air
source heat pump-
Electric baseboards
HRV VanEE 2000HE Air Pohoda Ultima 240E Air Pohoda Ultima 240E
Hot Water Air source DHW Air source DHW Air source DHW
ERS 82 ERS 88 Passive House

52. Labels/Third Party
Verification
• Energuide
• R2000
• Builtgreen
• LEED
• Passive House
• Net Zero
• Net Zero Ready
• Near Net Zero

53. In a nut shell
1. Net zero energy building performance depends on an on-site
photovoltaic (PV) system to generate the energy still required after
conservation and any other renewables
2. Optimal solutions require shrinking energy needs and therefore the PV
system so that:
1. You can afford the PV system
2. It will fit on your roof
3. Carefully designed conservation + an Air Source Heat Pump can
shrink the required PV system to a manageable size.
4. Keep it simple! Insulation and air tightness will get you there.The
science experiments either didn’t work well enough or were too
expensive.

54. Tempted to try this?
• It is way easier the second time.
• Start by looking at houses that have worked in your climate zone.
• Let someone else make the mistakes.
• Take the Passive HouseTraining- best investment there is in learning how
to do ultra energy efficiency
• For more info on how to do practical net zero energy design and
construction consider taking Marc Rosenbaum’s on line course at http://
nesea.cammpus.com/courses/zero-net-energy-homes--online

55. habitat-studio.com