The document summarizes key points from a presentation on passive house design. It discusses energy use in California homes, lessons learned from past passive house projects, and comparisons of energy use and assemblies between different passive house projects. Specific projects discussed include the Cottle Residence, Sunnyvale home, and Alamo home. Charts show similarities between projects despite different sizes, and that passive house designs prioritize thermal comfort over energy savings.

1. Bronwyn Barry, CPHD
One Sky Homes
Passive House California
North American Passive House Network
GREENBUILD 2016

2. q Where are we starting from?
q How low must we go?
q How’s this being done?
q Lessons Learned

3. q CA homes use 31% less than
the U.S. average
q Expenditure for energy about
the same as U.S. average
q 62M BTU energy use per
home = 18,170 kWh
q Average size = 1,525 SF
q 60% Single Family Homes
Source: www.eia.gov/consumpion/residential

4. Energy use: 18,170 kWh/yr
Ø Assume: 400 kWh/panel
Ø 12 kW PV Array
Ø = 45 panels!
Source: www.eia.gov/consumpion/residential
Min. Required Roof Area = 780 SF
(Assuming 17.3 SF/panel)

5. Cars: 12%
Residential:
5.37%

6. COTTLE
RESIDENCE

7. q 3,200 SF home (family of 5)
q 28 PV Panels (6.2 kW)
q 11,100 kWh production

10. PROJECT STATS
Co#le - CA Climate Zone 3
HDD/CDD 2335 574
Area/TFA 3200 SF 2776 SF
Net Annual Energy Use &
ProducCon 9356 kWh 11,100 kWh
PV 6.2 kW
Gas/Electric Split
Gas Cooking,
Solar Hot
Water with
backup
HVAC systems
Heat Pump,
NightBreeze
Cooling,
Solar
Thermal Hot
Water, HRV

11. ASSEMBLIES (hr.ft2.F/BTU)
ROOF/CLG: R-38
T-24 REQ’D VS. AS-BUILT
R-50
WALLS: R-25 R-26
WINDOWS: U-0.38
FLOOR/SLAB: R-0 R-14
U-0.3

12. COPYRIGHT ONE SKY HOMES 2016AFTER
BEFORE

13. SUNNYVALE

14. COPYRIGHT ONE SKY HOMES 2013

17. BEFORE
1'-11"
23'-3 1/2"
9'-9"
25'-1"
11'-81/2"
6'-7" 33'-1"
10'-4"
13'-4"
46'-8"
4'-0"
22'-2 1/2"39'-2"
PROPOSED ELEVATIONS 1/4" = 1'
FRONT - SOUTH EAST
SIDE - SOUTH WEST
SIDE - SOUTH EAST
REAR - SOUTH WEST
REVISIONS
1'-11"
23'-3 1/2"
9'-9"
25'-1"
11'-81/2"
6'-7" 33'-1"
10'-4"
13'-4"
46'-8"
4'-0"
22'-2 1/2"39'-2"
1019ValleyForgeDrive
Sunnyvale,CA94087
04.06.2012
CONTACT:AllenGilliland408-421-6808
PROJECT:NewHome@
Date
Scale
Drawn
Job
Sheet
SheetDescriptionDesignandConstructionby:
1820CottleAvenue,SanJose,CA95125
High-Performance,Zero-EnergyHomesPROPOSED
ELEVATIONS
A4
CSLB#822652
allen@oneskyhomes.com
SEZENSTRUCTURALENGINEERING
B. BARRY
1/4" = 1'-0"
408-421-6808
StructuralEngineeringby:
ONESKYHOMES
274E.HamiltonAve.,SteC,Campbell,CA95008
Voice:408-871-7273Fax:408-871-7274
CONTACT:BrianMoon,Sr.Engineer
SezenStructural@aol.com
PROPOSED ELEVATIONS
Prelim Window
Quote 6.22.12
1/4" = 1'
FRONT - SOUTH EAST
SIDE - SOUTH WEST
SIDE - SOUTH EAST
REAR - SOUTH WEST
1'-11"
23'-3 1/2"
9'-9"
25'-1"
11'-81/2"
6'-7" 33'-1"
10'-4"
13'-4"
46'-8"
4'-0"
22'-2 1/2"39'-2"
FRONT - SOUTH EAST
SIDE - SOUTH WEST
SIDE -
REVISIONS
1'-11"
23'-3 1/2"
9'-9"
25'-1"
11'-81/2"
6'-7" 33'-1"
10'-4"
13'-4"
46'-8"
4'-0"
22'-2 1/2"39'-2"
1019ValleyForgeDrive
Sunnyvale,CA94087
04.06.2012
CONTACT:AllenGilliland408-421-6808
PROJECT:NewHome@
Date
Scale
Drawn
Job
Sheet
SheetDescriptionDesignandConstructionby:
1820CottleAvenue,SanJose,CA95125
High-Performance,Zero-EnergyHomesPROPOSED
ELEVATIONS
A4
CSLB#822652
allen@oneskyhomes.com
SEZENSTRUCTURALENGINEERING
B. BARRY
1/4" = 1'-0"
408-421-6808
StructuralEngineeringby:
ONESKYHOMES
274E.HamiltonAve.,SteC,Campbell,CA95008
Voice:408-871-7273Fax:408-871-7274
CONTACT:BrianMoon,Sr.Engineer
SezenStructural@aol.com
PROPOSED ELEVATIONS
Prelim Window
Quote 6.22.12
1/4" = 1'
FRONT - SOUTH EAST
SIDE - SOUTH WEST
SIDE - SOUTH EAST
REAR - SOUTH WEST
AFTER COPYRIGHT ONE SKY HOMES 2013

18. PROJECT STATS
Sunnyvale - CA Climate Zone 3
HDD/CDD 2643 220
Area/TFA 2000 SF 1560 SF
Net Annual Energy Use &
ProducCon 5,765 kWh/yr none
Gas/Electric Split
Gas Cooking,
DHW
HVAC systems
1 ton Fujitsu
HP &
Panasonic
Bath Fans,
HRV

19. ASSEMBLIES (hr.ft2.F/BTU)
ROOF/CLG: R-38
T-24 REQ’D VS. AS-BUILT
R-40
WALLS: R-25 R-26
WINDOWS: U-0.38
FLOOR/SLAB: R-0 R-24
U-0.3

20. Table 9: Annual Site and Source Energy Savings Normalize to TMY3
Source: http://www.nrel.gov/docs/fy15osti/63085.pdf
MEASURED SAVINGS:
§ $499 per year energy cost
§ 40% Source Energy

21. ALAMO

25. PROJECT STATS
Alamo - CA Climate Zone 12
HDD/CDD 2602 1578
Area/TFA 3000 SF 2342 SF
Net Annual Energy Use &
ProducCon 8,400 kWh 13,785 kWh
PV 7.5 kW
Gas/Electric Split All Electric
HVAC systems
Heat Pump,
HRV

26. ASSEMBLIES (hr.ft2.F/BTU)ASSEMBLIES (hr.ft2.F/BTU)
ROOF/CLG: R-38
T-24 REQ’D VS. AS-BUILT
R-46
WALLS: R-19 R-28
WINDOWS: U-0.57
FLOOR/SLAB: R-0 R-14
U-0.3

27. 3200 3000 1560 1525
0
2000
4000
6000
8000
10000
12000
14000
16000
18000
20000
Co,le Alamo Sunnyvale Av.CA
Energy Use & Floor Area
Energy Use
Floor Area
2.92 2.80
3.70
11.91
0.00
2.00
4.00
6.00
8.00
10.00
12.00
14.00
Co.le Alamo Sunnyvale Av.CA
EUI (kWh/sf.yr)

28. www.passivehousecal.org

29. 0 1000 2000 3000 4000 5000
BERNSTEIN
MIGHTY HOUSE
CLARUM OFFICE
POE STREET
FIELD/CHIARELLO
STANFORD ST
OXFORD ST
Treated Floor Area (>2)
Large
Average Size
Tiny
MIXED USE BLDG
SINGLE FAMILY HOME
COMMERCIAL OFFICE BLDG
SINGLE FAMILY HOME
SFH
SFH

30. 0.00 5.00 10.00 15.00 20.00 25.00 30.00 35.00 40.00 45.00
BERNSTEIN
MIGHTY HOUSE
CLARUM OFFICE
POE STREET
FIELD/CHIARELLO
STANFORD ST
OXFORD ST
Floor/Slab (hr.A2.F/BTU)
0.00 5.00 10.00 15.00 20.00 25.00 30.00 35.00 40.00 45.00
BERNSTEIN
MIGHTY HOUSE
CLARUM OFFICE
POE STREET
FIELD/CHIARELLO
STANFORD ST
OXFORD ST
Overall Window (hr.A2.F/BTU)
0.00 5.00 10.00 15.00 20.00 25.00 30.00 35.00 40.00 45.00
BERNSTEIN
MIGHTY HOUSE
CLARUM OFFICE
POE STREET
FIELD/CHIARELLO
STANFORD ST
OXFORD ST
Exterior Walls (hr.A2.F/BTU)
0.00 5.00 10.00 15.00 20.00 25.00 30.00 35.00 40.00 45.00
BERNSTEIN
MIGHTY HOUSE
CLARUM OFFICE
POE STREET
FIELD/CHIARELLO
STANFORD ST
OXFORD ST
Roof (hr.A2.F/BTU)

31. Ø Assemblies were all very similar, despite large
floor area variation
Ø All used simple forms and roof design
Ø None have an attached garage
Passive House Design-related observations:

32. Passive House &
ASHRAE Std 55 –
Thermal Comfort
NONE of our clients have asked us to lower their energy bills.
ALL have asked for better comfort or to eliminate mold.
COPYRIGHT ONE SKY HOMES 2013

33. q Windows (+ Shading) Matter
q Air sealing gets you half way there
q Roof Design and Form factor are HUGE
q Drive your own energy model!
THANK YOU!
Bronwyn Barry, CPHD
One Sky Homes
www.passivehousecal.org
www.naphnetwork.org