design philosophies - Sustainable House Day

72 Main Rd, Mt Egerton
The dwelling occupies a very small footprint on the house block. The placement of any
dwelling or sheds and there size was dictated by the EPA and Barwon Water. It was
pointed out that the heavy reactive clay on the block was not capable of absorbing the effluent generated from a normal septic tank system. This issue was permit “paramount”.
The septic system solution became a marriage of a Biolytix treatment system pumping
treated effluent to water absorbing plants within built 20sq metres of Reed Beds and 50m
of Niimi trenches. (The Biolytix system is purely biological). Added to this is the installed
sub surface irrigation which was intended to keep the Niimi trench plants alive in summer
and periods of reduced load from the Biolytix. To date this system has not been required.
The effluent disposal field now forms a working display of water absorption and a very attractive albeit alternate rear garden area. The plants in the absorption system have been
sourced locally or are specific water loving plant life. In the middle of the disposal field is a
very proud native tree fern which has been in situ since 2003, yes, right thru the drought.
It is totally out of place but it seems to work for us. As it continues to grow it may well become a feature of the rear garden.
Life for us on this block began after the purchase in 2003 when the old CFA shed was uprooted from its street front position then moved up to the back corner of the block. The
shed was re-instated with a concrete floor, power and an extremely large open fire place.
It has since had an extra layer of tin roofing added which enabled some damp and poor
insulation issues to be resolved.
The shed now has a large heavily insulated duplication which doubles as an overflow bedroom area 3.6m x 7.2m. This detached area is fully lined and has a concrete floor, the
heater is a unique wooden ship heater design. Surrounding the shed is the storm water
protection and collection system being cut off drains and retainers walls. The rain water
from the sheds is collected in 2 tanks, 5000 ltr and 7000 ltr.
Very early heavy landscaping occurred after a re-think of the block’s slope and water runoff issues. It became clear that flat area terracing and cut off drains would be necessary
during heavy rain and the local drenching mist. These early excavations provided flat areas for safely parking vehicles and they doubled as storm water retention areas too.
At the front of the block is a terraced half circle driveway which creates and defines the
main front lawn. The block’s lowest cut off drain directs storm water around the half circle
drive thus watering the main feature tree and including 2 striking Snow Gums and others.
From the street crossover the driveway proceeds up the north side of the block past the
rear terraced area at the back of the house then up to the rear sheds. There are another 2
cut off drains in this last stage of the driveway, these drains direct water to the treed north
boundary. This storm water retention is key the survival of the quiet mix of exotic and native trees and shrubs. In the garden there is no need for garden reticulation or taps.
These drains also protect the crushed rock from any heavy erosion.
It was proposed that the dwelling be placed along the southern boundary and close to the
street. This consideration is necessary to benefit from maximum exposure to the northern
sun and a limited concern about trees shading any solar panels and house in winter. Finally, the dwelling being close to the street was as a result of septic set-backs and the size
of the effluent disposal field at the rear of the house
Once the shed was set up and the power installed there was time then to implement the
design blanket for the dwelling.. The main street is populated with a number of older buildings none more striking than the local Mount Egerton Public Hall. An attempt was made to
blend a new house into the old streetscape; the underlying theme was the steep roof
shapes of these old buildings. It was with an economy of scale and a love for the old
world that the Orange House had its roof shape almost dictated by its surrounds.
At last, back to the size, shape and appearance of the proposed dwelling. The roof shape
and structure was now a primary design principle. The steep pitch and internal truss design define the upstairs internal spaces. The dormers and roof is deliberately angled and
kept simple. The roof pitch is 45 degrees to maximise roof strength. All roofing iron,
spouting and fascia trim are maintenance free colorbond steel.
The wide verandas provide window and door protection, extra water catchment, platform
to access most of the roof and in a social sense they are very handy dry areas when it is
raining. The east facing 3 metre wide front veranda defines the garage space and the 2
lower rooms area below. The north facing 2 metre wide side veranda is for shade. The
solid balcony linings reflect a nautical theme along with the ability to be self cleaning as on
a ship. The house cladding, decking and veranda balustrading are designed and built to
withstand a potential fire impact. Thus the veranda decking is 18mm compressed fibro
cement sheeting, which water proof and fire resistant.
The type of material for the internal ceiling and wall cladding was the first decision in the
design phase. The sub soil on the block is highly reactive clay. This knowledge led to the
special concrete apron at the rear of the house; this functions to eliminate storm water
passing under the dwelling. Secondly, the extra strength of 9mm bracing ply sheets were
factored into the the internal cladding. The house is braced at roof and walls but extra
braced over every internal surface by the bracing ply.
The ceiling height was set at 2.7m to facilitate good air flows and for greater thermal mass
volumes of air, capturing heated air and buffering against the hot air in summer.
The windows are all aluminum 12mm double glazed. They are either set at 1m from floor
level or at 1.8m where privacy is an issue. It is hoped the window placement will allow
maximum view without the need for curtains and blinds.
The external doors are solid hardwood, stained and timber treated; no lacquering at all.
The internal trim is all merchant grade plantation pine. This was chosen not only for its low
cost but for the beautiful visible knots and grain. Most internal trim is lightly stained and
timber treated, no lacquer. The walls and ceiling are lacquered with floor grade, water
based, low emitting lacquer.
Comfort within the house is of paramount importance. It is cost effective, especially when
low electricity bills arrive. The energy efficiency within the house design was achieved at
every purchase choice. The wall, ceiling and roof cavity insulation is top grade polyester,
this includes acoustic and themal R2 batts in the inter floor spaces, i.e. internal ceilings.
The under floor insulation is aircell 400, which is damp and vermin proof. This was an early choice because the yellow tongue chip board floor was planned to be timber treated and
lacquered to provide the final floor finish. This may alter as the block becomes less muddy.. But, at the moment the flooring is well protected, water proof and it looks great.
Wet area flooring is a one piece compressed fibro cement sheeting at the same thick ness
as the balance of the house flooring. The sheeting is naturally water proof but is lightly
stained to give a cork like appearance. All wet areas are tanked to Australian standards.
Without giving away to much, the downstairs has a very traditional but comfortable look. A
wide walnut stained stairway leads from the utility area up to the bedroom retreats.
Each upstairs bedroom has its own enclosed attic styled veranda. The up stairs is truly an
escape. Potential layouts are endless. Of note here is the verandas being within the roofline, the effect is quite unique, a stand out feature of this house design and function.
The den down stairs is the engine of the house. It is from here that radiant heat convects
naturally throughout the house. The Gourmet Cooker Heater is a gem. It also boosts the
hot water along with the boost from the 3 solar hot water panels on the roof.
There is no electricity turned on to the electric hot water service. Yes, NO POWER. The
hot water system is boosted in summer entirely by solar hot water panels, and then in the
winter months the slow combustion heater not only heats the house but also heats the hot
water for free.
The house is only a part of the overall plan to conserve energy and resources. Externally
the block has a 15% slope to the street. This has allowed detailed landscaping and
earthmoving in order to not only capture the rain run off but direct the water to where the
plantings benefit the most.
The rain water is harvested and stored in 6 tanks around the house and sheds. Eventually
this water will be reticulated around the block from a gravity tank supplied by a solar
transfer pump.
All fixing of cladding and trim is by screws only. The advantage is that at any time some
trim or a wall panel can easily be removed for extra works then replace in situ without any
The whole of life approach to the build exemplifies savings in a number of areas, none
more so than the minimal electricity consumption, (circa $150 per qtr), and of course water harvesting and distribution on the block both to the house and garden.
Mt Egerton - Orange House
organic house
the orange house
An organic house should strive for functional harmony within and without
Some design principles for self builders, architects and draftsmen:
building ethics, i.e. size / style
building block choice, east aspect, high rainfall, height above sea level
neighborhood sensitivity, period architecture, age of neighborhood dwellings
build cost within means, planning for the long term
sustainable materials, healthy materials, local materials, framing timbers & claddings
wet weather dry areas, under cover areas
rain water water capture, water consumption, necessary water reserves, water tanks
storm water retention, block landscaping, cut off drains and terracing
temp. control, i.e. ambient heat retention, solar gain, passive solar heating, thermal mass
temp. control, i.e. energy use, heating, hot water service, cooling, windows, insulation,
septic area, type, local soils