Passive Solar Architecture
• Uses building elements for energy
capture and storage
• Windows for solar gain, daylighting,
• Overhangs, fins, and shading for solar
• Convective, radiant sky, or evaporative
• Work even when the power is out!
Passive Solar Architecture
First described in Greece and Rome
Driven by rising charcoal prices
Widespread use of solar design
Solar cities, solar access, passive
heating and cooling
• If our designs are to be correct we
must...take notice of the countries
and climates in which they are built.
Solar cities develop
• Planning and street layout
• Building orientation
• Passive design improved comfort and the
quality of life
Summer comfort
• A well to do
Roman family
would have
fountains and
pools for summer
• Today we might
use an indirect
Passive Heating 1.0
• Most people
first think of
passive solar
• This is easy face south, add
windows or a
solar room or
Bodie, California 1930s
1930 Swiss Solar
• Fuel shortages
and high costs
after WWI led to
solar design in
Germany and
• Neubühl, near
Zurich, is a
solar village
1940s Solar USA
• George Fred Keck designed Solar Park homes for
Howard Sloan in 1941
• Good orientation for winter, solar control in summer
but under-insulated, not enough mass
• Illinois was the home of Libby-Owens-Ford a double
pane glass maker who supported solar development
1950 Solar Sustainable
• A rammed earth
passive solar home
was built in 1950 by
David and Lydia
Miller in Greeley,
• The owners and
architect J Palmer
Boggs were
delighted with
1951 Solar Design Tools
• Architects in the 1950s
had solar design tools
for the first time
• Solar homes were built,
primarily by architects
for the well-to-do
• But subsidized
electricity, low cost air
conditioning, and mass
production soon killed
solar design
Passive heating 2.1
• The next step was
adding more thermal
mass to store
energy for heat at
night in winter
• A concrete floor or
plaster walls provide
some mass
• But more may be
1956 Mass Wall -- France
Trombe wall
Trombe Wall - Odiello
• Masonry wall for
thermal mass
• Glazing outside
gathers solar
• Vents allow heat
in/reduce night
• American
Edward Morse
• Rediscovered in
France by Félix
1961 Passive Solar School
Wallasey, England--Emslie Morgan, architect
The first effective large passive solar design
Double glazing, high mass with external insulation
Good interior daylighting
Students, sun and lights provided all the heat
1972 Water Is Often Best
• Steve Baer
built this high
water wall
• Corrales,
New Mexico
• His company,
is still active
1976 Water wall
• This water tank was
the first rectangular
water wall, 1976
• Mass floor, solar
orientation and
overhangs for solar
• Also 3 tank ICS
solar water heater
• Energy use 90%
below average
Passive heating 2.2
Better insulation, more mass
Water wall passive home (DAB solar design)
Smaller rectangular steel water tanks
Energy use cut 75%
Cooling 3.0 - Solar Control
• Overhangs work on
south facing walls
• East and west may
need fins, shutters,
awnings, shades
• Toldos cover courtyards
• Landscaping helps,
trees to SE/SW not
• Green walls
Cooling - Night Vent
• Night convective
• Water wall office, Jon
Hammond 1975
• Culverts add surface
area for improved heat
• Cross and stack
ventilation during the
day can also provide
cooling by evaporation
Enhanced ventilation
• Traditional
designs also
utilized ventilation,
often with
cooling for a boost
• In Iran cool air
may be drawn
from underground
water tunnels
• Fountains and
pools enhanced
cooling breezes
Integrated Design 4.0
ICS water heaters
Roll down awning-summer
Water filled culverts behind
• Greg Acker
designed this
culvert water wall
• Solar control,
night vent cooling
• Direct gain solar
heating with a
water wall
• 70% savings on
energy use
Roof mass integrated design
• Roof mass can
be heated in
winter by the
• Cooled in
summer at night
• Water or
100% Heating and Cooling
• Harold Hay,
Ken Haggard
and Phil Niles
full scale
house 1973
• Sliding
panel system
not well
Improved roof pond system
• Jon Hammond
redesign uses
hydraulic rams
• Lids up on cool
summer nights
and closed in
the day
• Lids down on
winter nights
and up on sunny
winter days
More cooling for hot climates
• 1970s - The
Research Lab
in Tucson
• Research on
the excellent
performance of
cooling towers
Evaporation and radiant sky
cooling -- the Cool Pool
• A shaded evaporating
roof pond can maintain
comfort under extreme
• Radiation to the cool
sky adds to evaporation
• Performed very well in a
hot parking lot at the
California State Fair
Un-integrated design
South windows should
Be 10-20% of floor area,
rarely more
• Solar brutal - too many
windows, not enough
insulation, thermal
mass, or solar control
• Can be too hot in any
season--but still cold on
dark winter days
• Common in 1970s New
Mexico but this example
is from Oregon
• Still done today - poor
orientation can be
Estimated costs
0.002 cents per kwh
Passive design DHCV
0-2 cents per kwh
Passive water heater
1-2 cents per kwh
Active water heater
2-7 cents per kwh
10-30 cents per kwh
Daylighting 5.0
• Daylighting
reduces cooling
• Improves
people’s attitude
and health
• Saves energy
• Often the key
factor in
Easy to model
• Light shelves on
south facing
walls are very
effective for
• They control
glare and
bounce light
further in
• Models allow
quick checks of
Orientation (12 ft)
Taller ceiling (16 ft)
Light shelf (25 ft)
Angled ceiling (28 ft)
Optimized (39 ft)
• Use physical and/or
computer model
Community design 5.0
• Mike and Judy Corbett
start a remarkable solar
development with passive
solar heating and cooling
• More than 200 units,
designed for bikes, walking
and community building
• 50% less energy used
than adjacent
developments (1975)
• Mixed use
• A delightful place
The challenge in 1980
• We knew how to do very high
performance buildings
• With super-insulation and effective
thermal mass (water best)
• How could we build super-insulated
buildings with high internal mass at
competitive cost?
The answer emerges
DB, Matts Myhrman, Bill Steen
A consulting job for a
pig farmer in 1983 led
me to straw bale
Historic straw bale
buildings in
Nebraska, Wyoming
and Alabama
In 1989 the first straw
bale workshop was
held near Oracle, AZ
1994 The Straw Bale House
• Straw bales provides
high insulation value
and significant amounts
of plaster for distributed
thermal mass
• Just five years later we
published the first big
book on straw bale
• Sale have now passed
• There are more than 20
sb books in many
Straw bale passive solar homes
Near Bishop, by Ken Haggard and Pliny Fisk
Probably the first permitted straw bale in California
With composting toilets, greywater biobeds
Higher performance--modest price
Integrated commercial design 6.0
• Daylighting
• Passive heating,
cooling, ventilation
• General Services
would not accept a
floating temperature in
our 240,000 square
foot building in 1975
• Even after we showed
it would be better than
existing buildings
• 88% energy savings
Jon Hammond, David Bainbridge, Loren Neubauer, Jim
Plumb, Marshall Hunt, Denny Long, Living Systems
Office space 1976
• Ken Haggard and SLOSG submitted a roof pond
design the next year
• It would have provided 100% heating and cooling
• The design was not “hierarchical” enough
Office space
• Ken Haggard, Polly
Cooper and their staff
have designed more
than 200 passive solar
buildings since 1975
• This is their passive
solar, straw bale off-grid
• Daylit, natural
• Waterwall for heating
and cooling
Assembly building/offices
Ken Haggard and Polly Cooper
San Luis Obispo Sustainability Group, 2006
• Daylit, naturally
heated, cooled
• Energy use
82% below
energy code
• Water walls for
thermal mass
• Straw bale
Police station
• Daylit, light
• Passive solar
• Police station
• Visalia
Jon Hammond, Indigo Architecture, 2006
Passive Solar Europe
• Germany and
Scandinavia began
passive solar home
building in the 1990s
• Good resources and
• Typical 70-90%
• Driven by true cost
pricing 30¢ kwh
PassivHaus Institute
Big office buildings!
• ING (NMB) bank building in Amsterdam,
550,000 sqft by Ton Albert (1987)
• Daylit, natural ventilation
• Passive and active solar
• 90% energy use reduction no increase in cost
• Reduced absenteeism
• Overcrowding led to changes in systems mechanical added
• Operable windows did experience some
noise issues
Mixed use passive
• The Prisma building
in Nuremberg
• Design Dr. W. Stahl,
• Daylit, passive
heating, cooling and
• 140,000 square feet
The global challenge
• Simple passive solar straw bale homes
• Thousands underway in China thanks to Kelly
Lerner and other volunteers, ADRA
• In Mongolia energy use was cut 80%
Passive solar obstacles
An anti-solar
could hardly do
• Perverse incentives--almost everyone involved has
incentives to do the wrong thing
• Key issues - subsidies, developer v/s client, tax code
• Result: sealed, unhealthy, unsustainable buildings
• Estimated lost productivity and medical costs $200
billion a year (Dept of Energy)
What should we expect?
• Health, comfort, joy and beauty!
• 90% less energy needed for heating
and cooling
• 90% daylighting
• Natural ventilation with operable
windows for most buildings < 6 stories
• Comparable first cost
• More sustainable materials

A Solar History