7/27/2019 The Flywire House - A Case Study in Design Against
Brushfire - David Holmgren
2/19
Catastrophic bush res have been an integral part o the history o
Europeansettlement in south eastern Australia. This provided a
context or the inclusionbush re resistant house and landscape
design as one o the elements that BillMollison and I brought
together in Permaculture One in 1978. That pioneeringwork was
directly infuenced by Bill Mollisons then recent personal
experience o surviving the great Tasmanian bush res o 1967, in
which he saved his own (not atall re resistant) house and then
saved several more nearby houses, while manymore unattended ones
burnt down. Another key theme in that early work wasthe recognition
that the nutrient rich, orests o ood producing tree species
andappropriate livestock that were one outcome o permaculture
design, were inherentlyless re hazardous and even re retardant
compared to uel rich sclerophyll orestsdominated by eucalypts or
pines.
The experiences o many during the 1983 Ash Wednesday res as well
as extensiveresearch by CSIRO and others con rmed much o this
integrated bush re resistantdesign as refecting the consensus o
expert opinion. Flywire House embodiesthis bridge between
permaculture as radical ringe innovation on the one hand
andmainstream science and public policy on the other. The infuence
o the permaculturevision o the re retardant ood orest is moderated
in the Flywire House design.Like the building design itsel , the
landscape design refects the more conventionalsensibilities o a
mainstream audience that the original design project
addressed.Secondly the low ertility clay soils prone to
waterlogging in winter and hardsetting insummer were not likely to
support a healthy high density o diverse ood producingtrees that
orm a close canopy orest with deep enough root systems to
remainhealthy and re retardant in a severe drought such as the
82-83 Victorian droughtthat was regarded as a one in one hundred
year event.
About the time Flywire House was published as a book (1991), the
early predictionsabout global warming were suggesting greater
intensity and requency o bush resbeing one o the prime consequences
or southern Australia. At the time these
Foreword
eBook design and production Richard Telford. www.permacultu
reprinciples.com
7/27/2019 The Flywire House - A Case Study in Design Against
Brushfire - David Holmgren
3/19
warnings seems to speak o the middle o the next century but 18
years later a tera decade o drought and increasing bush re
intensity and requency, it seems likewe are already well down the
slide into the climate crisis. The res o Black Saturday(7 th Feb
2009) killed nearly 200 people, destroyed thousands o homes and
burntthrough nearly hal a million hectares o orest and armland. The
causes o andresponses to this great tragedy is now the subject o a
Royal Commission.
In reviewing Flywire House 26 years a ter the original project,
I eel con dentthat the principles and even most o the design
details o this case study are stillrelevant and incorporate almost
all the elements o current bush re resistant designstandards. What
makes Flywire House unique in the bush re design literature isthat
re resistant principles emerge almost seamlessly rom the wider
permaculturedesign ramework that aims to create a system that is
productive, low impact and
resilient. I believe the relatively conservative approach to
landscape design withseparate and distinct manageable vegetation
systems is more re resistant andmore healthy that attempting to
create the classic permaculture ood orest o highdensity vegetation
in a climate with dry windy summer conditions on very poor
soils.
That being said, the question o what one would do di erently is
o ten mostprominent in the readers mind. Two speci c technical
points and two more generalcontextual ones come to mind at this
point o refection.
There is some evidence that the ceiling spaces o houses are a
great source o ember
ignition and that a cathedral ceiling is more re resistant. In
view o the limitedexperience o Australian builders (both owners and
pro essionals) in tightly sealedconstruction, the fat ceiling shown
in Flywire House might not be the best.
In landscape management, there is considerable evidence that
thinning o denseeucalypt regrowth orest, signi cantly reduces
likelihood and intensity o crown
res, as well as improve uture timber values and diversity o
ground cover nativevegetation. Thinning to retain slightly less
fammable eucalypt species in a smallpart o the orest closest to the
house is included in the design, but I think a
continuous program o orest thinning to reduce re hazard, improve
ecological anduture timber values and provide a constant supply o
carbon neutral uel should be
an essential element o any bush property. Ironically I remember
the reason or thisparticular omission was more political than
technical in wanting to ocus attentionon the house and immediate
landscape design as the primary ocus o bush reresistant design and
not support the tendency to blame wider nature and de ault
tocutting down trees (i necessary, all o them).
The more contextual doubts about this particular case study,
concern the exampleo an individual house on a steep ridge property
surrounded by native orest as aplace o settlement. While I eel the
design is still robust or the site, we need toacknowledge two
points that undercut those permaculture aims or productive,
lowimpact and resilient design.
Landscapes that are steep, low ertility and orested (especially
with eucalyptus)are inherently vulnerable in ways that cannot be
ully compensated by good design(or vegetation management) as well
as being di cult places to maintain access,services including water
supply and grow ood. In a world o climate change andenergy descent,
these landscapes may go back to being orested and/or
grazinglandscapes without the rural residential development that
has developed in the lasthal century.
Secondly single house rural property development with small
amily or household
numbers o people who commute or work and other activities are
inherently lesssustainable, productive and resilient than clustered
and shared (eco village andco-housing) developments where the
unction o bush re resistant design andpreparedness can be supported
by the economies o scale and resilience thatcommunity provides. In
the ace o the un olding climate/energy/economic crisis,more than
ever we need to band together and co-operate to survive and thrive
in anuncertain uture.
David Holmgren Melliodora February 2009
