This document summarizes the key passive solar design features of the House Solarei in New Zealand. It includes diagrams and descriptions of the trombe wall, passive ventilation system using sloped ceilings and ventilation windows, deciduous landscaping, window placement and sizing, and rainwater harvesting. The interior uses macrocarpa timber for its durability and sustainability. Diagrams illustrate how the design maximizes winter sun exposure and minimizes summer sun to naturally heat and cool the home.

1. Sustainable
Architecture:
Passive
Solar
Design
(House
Solarei-­‐
Architect
Duncan
Firth).
Resource
compiled
&
edited
by
W
van
Zyl.

2. CASE
STUDY:
HOUSE
SOLAREI
*Some
pictures
with
details/annotaOons/diagrams
to
illustrate
and
explain
some
basic
principles
of
passive
solar
design.
Comments
and
details
on
the
following:
• PASSIVE
VENTILATION
• “TROMBE”
WALLS
(HEAT
SINK)
• DECIDUOUS
LANDSCAPING
• WORM
FARM
(COMPOSTING)
• CLERESTORY
• INTERIOR
TIMBER
• WINDOW
SIZE,
POSITIONING
AND
WINDOW
DETAIL
• PERGOLA
AND
SCREEN
WALL
• LARGE
ROOF
OVERHANG
• HARVESTING
RAINWATER
• LocaOon:
New
Zealand
Pictures
courtesy
of
architect
Duncan
Firth
(Solarei.com)

3. SUN’S
RAYS
The
sun
would
heat
up
these
floors
in
(Winter)
Yellow
-­‐
North
facing
(will
act
as
heat
sink)
CLERESTORY
(L-­‐
SHAPED)
Passage
and
entrance/exit

4. PosiOon
of
the
sun
during
winter
and
summer:
Diagrams
show
the
design
details
and
passive
solar
principles
applied
in
sustainable
architecture.

5. The
interior
walls
(concrete)
and
floors
(concrete)
will
absorb
heat
of
the
sun
and
release
it
during
the
day
(winter
months).
See
slanted
ceilings
with
venOlaOon
windows.
This
means
warm
air
will
rise
and
follow
the
slanted
ceiling
and
the
warm
stale
air
would
escape
through
the
venOlaOon
windows.
This
will
sOmulate
the
passive
venOlaOon
in
the
building
and
create
unassisted
movement
of
the
air.
Cooler
air
will
now
flow
in
from
the
bo]om
creaOng
a
constant
flow
of
cooler
fresh
air
during
summer.
“TROMBE
WALL”

6. Xeriscape
gardening:
Watering
and
irrigaOon
are
limited
(rocks
included
and
the
choice
of
plants).
Search
xeriscaping
to
find
out
more.
This
technique
could
be
used
in
suaOnable
landscape
design.
Interior
walls:
concrete
blocks
will
absorb
heat
during
winter
and
release
it
during
the
cold
winter
days
(‘Trombe
wall’).
Timber
to
the
interior:
Macrocarpa
shelves.

7. XERISCAPING:
Xeriscaping
for
us
amateur
gardeners
usually
means
gardening
in
an
almost
waterless
environment.
Usually
in
a
desert
like
climate
or
geographical
area
where
water
is
sparse.
Really,
we
think
of
it
as
water-­‐wise
gardening
with
drought
resistant
plants
that
can
survive
with
li]le
or
no
water.
Also
water
conservaOon
techniques
like
mulching
and
collecOng
rain-­‐water
come
to
mind.
It
could
also
include
a
gardening
style
or
conservancy
way
of
thinking,
where
we
a]empt
to
build
an
outdoor
space
that
can
survive
with
li]le
or
no
water.
A
producOve
garden
built
on
the
idea
that
no
water
is
wasted,
that
all
available
natural
water
is
used
for
the
best
and
that
planOngs
are
thought
out
in
terms
of
water
conservancy.
Read
more:
h]p://www.gardening-­‐advice.net/xeriscaping.html#ixzz1ptUPMsDd
SomeOmes
climate
dictates
the
necessity
for
a
Xeriscape
garden
and
someOmes
it
may
be
a
choice.
Xeric
Gardens
with
drought
smart
plants
are
very
a]racOve
for
whatever
reason
you
want
to
create
one.

8. Typical
Xeriscaping:

9. DECIDUOUS
TREES
AND
SUSTAINABLE
ARCHITECTURE
(Landscape
design):
DECIDUOUS
TREES
IN
SUMMER
DECIDUOUS
TREES
IN
AUTUMN
DECIDUOUS
TREES
IN
WINTER

11. The
Living
Deck

12. SINGLE,
DOUBLE
AND
TRIPPLE
GLAZED
WINDOWS
–GAPS
FILLED
WITH
ARGON
GAS
Double
glazing
adds
an
insulaOon
layer
to
your
windows,
providing
you
with
the
following
benefits:
A
warmer
home
in
winter,
a
cooler
home
in
summer
with
condensa1on
substan1ally
reduced.
On
top
of
this
is
the
reduc1on
of
fading
damage
and
UV
light,
improved
noise
insula1on
and
improved
security.
UV
RAYS
OF
THE
SUN:
Note
that
the
glass
is
treated
so
the
damaging
UV
rays
of
the
sun
is
reduced
inside
the
house.
It
means
the
curtains,
carpets,
and
furniture
colours
will
not
fade
or
decay
at
the
normal
rate
as
expected
in
normal
condiOons
where
just
ordinary
one
layer
of
translucent
glass
is
installed
to
the
windows
of
a
house.
DOUBLE
GLAZING

13. Example
of
the
applicaLon
of
Marcracarpa:
The
interior
of
the
dwelling
(kithen
cupboards
and
floors)
is
shown
in
this
picture.

14. WHY
USE
MACROCARPA
TO
THE
INTERIOR?
THE
TIMBER
WITH:
BEAUTY..
STRENGTH..
DURABILITY..
SUSTAINABILITY
Macrocarpa
has
become
the
Omber
of
choice
for
many
home
owners
of
today.
Because
it
is
not
treated
with
chemicals,
it
is
borer
resistant,
and
it
is
becoming
the
popular
opOon
for
public
areas
such
as
schools,
parks,
golf
courses
and
home
gardens.
Macrocarpa
is
90%
plantaOon
grown
trees,
for
high
quality
Omber.
Macrocarpa
is
a
New
Zealand
exoOc
with
quite
extensive
new
planOngs.
Macrocarpa
is
recognised
as
one
of
the
most
eco-­‐friendly
Ombers
New
Zealand
produces.
DID
YOU
KNOW?
Building
with
wood
will
make
a
significant
contribuOon
to
reducing
CO2
in
the
atmosphere.
That
1
Tonne
of
wood
has
absorbed
approximately
1.7
tonne
of
carbon
net,
amer
manufacture.
ie.
By
simply
choosing
wood
an
average
Omber
house
reduces
CO2
by
50
tonnes
(equivalent
to
that
emi]ed
by
flying
12
Omes
around
the
world
or
what
a
car
could
use
during
its
enOre
life).
By
just
choosing
Omber
cladding
alone,
on
average
8.5
tonne
of
CO2
has
been
taken
out
of
the
atmosphere!
That
wooden
ceiling
sarking
(sarking
is
the
use
of
wood
panels,
or
"sarking
boards“)
would
also
reduce
CO2
by
approximately
8.5
tonne.
That
carbon
is
'locked
up'
for
the
life
of
the
house.
Any
Macrocarpa
waste
is
environmentally
safe
and
friendly
(shavings,
sawdust
for
the
garden
and
farm,
off-­‐cuts
for
firewood).

15. Timber
pergola
to
the
western
side
of
the
dwelling:
Will
act
as
a
screen
for
the
late
amernoon
sun
(sun
setng
in
the
west).
In
Summer
it
will
be
very
hot
and
the
pergola
would
assist
by
keeping
the
paCo
cool.
The
screen
wall
to
the
far
right
will
also
assist
with
shading
and
at
the
same
Cme
it
will
act
as
a
wind
screen
for
the
paCo.
Sun’s
rays
(late
amernoon)

16. Veggie
garden:
Planters
filled
with
vegetables
(garage
in
the
background)
.
The
harvested
rainwater
will
be
used
to
irrigate
the
garden
and
the
garden
will
provide
the
members
of
the
household
with
fresh
vegetables
on
a
daily
basis.
This
is
a
very
cost
effecOve
and
sustainable
way
to
add
healthy
food
to
the
diet
of
the
members
of
the
household
at
no
extra
cost.
Scraps
from
the
kitchen
(grinded
coffee,
teabags,
cardboard,
food
scraps,
etc.)
could
be
used
to
“feed”
the
Oger
worms
in
the
compost
box
(earthworms
break
down
the
scraps
and
convert
it
into
ferOle
soil).
Search
worm
farms
to
learn
more!

17. Bath
tub
used
as
a
worm
farm:
All
the
food
scraps,
cardboard,
tea
bags,
grinded
coffee
etc.
from
the
kitchen
is
mixed
into
the
soil
to
feed
the
earth
worms.
The
worms
will
consume
the
scraps
and
produce
top
quality
compost
for
veggie
gardens
Earth
worms
are
very
effecOve
to
break
down
scrap
food
and
lem
overs.
The
worm
juice
and
compost
are
invaluable
for
effecOve
sustainable
gardening.

18. Large
roof
overhang:
The
large
roof
overhang
will
shade
the
house
during
the
hot
summer
months.
At
the
same
Ome
it
is
not
too
large
so
the
winter
sun
will
not
be
able
to
shine
into
the
house
(sun
is
lower
during
winter).
The
key
is
to
get
the
balance
right.
Deck:
Timber
deck
has
a
concrete
slab
below
it
so
the
rainwater
would
run
off
and
it
will
get
channelled
to
the
water
tank
(under
ground).

19. Cerestory:
Also
called
a
‘Stack’.
Concrete
walls
will
heat
up
during
winter
and
release
the
heat
during
the
day.
This
will
reduce
the
heaOng
bill
as
less
electrical
or
gas
heaOng
is
required.
It
will
also
release
heat
into
the
colder
areas
of
the
house
(south).
VenLlaLon
windows:
See
the
slanted
ceiling
and
verOcal
venOlaOon
window
at
the
top.
The
slanted
ceiling
will
enhance
the
air
flow
(warm
air)
towards
the
top
window.
At
the
same
Ome
cooler
air
will
flow
in
from
the
outside
(bo]om
entry).
SLANTED
CEILING
ASSISTING
AIR
FLOW
WINDOW
TO
IMPROVE
PASSIVE
VENTILATION