Under the Choko Tree


Resilience rating: NA
Location: St Clair, Western Sydney (pop. 20,000 of 4.3m)
Rainfall: 785mm
Soil: Sydney clay
Build: 1970’s brick veneer house on piers with concrete tile roof
2016 Property Value: AU$NA
Household: 2 adults
Land Size: 600m²
Floor space: 110m²
Roof area: 120m² (house) + 25m² (Garage) 21m² (carport)
Water tank storage: 11,500lt
Tank water use: as required for irrigation
Mains water use: 245lt per day
Greywater: all water from the shower/bath is directed to the banana circle and all laundry water is directed to a constructed wetland and thence fruit trees
Power: 1kw grid tied system; 500w stand alone system. Annual Power exported:1047kWh
These figures are how we operated up to a Nov 2016. We are now almost off grid with 1.2kw of panels connected to 2 nickel iron 24 volt battery banks contributing an average of 5.6kWhrs per day over Nov 2016. Extra panels are planned to take the system up to 2.5kw.
Annual Power imported: 1518kWh
Av. Power produced: 2.87kWh p/d
Av. Power used: 4.16kWh p/d
Annual Gas used: 1102MJ (0.5 x 45kg cylinder/year)
Annual Wood used: 1m³
Food production: 80% veg/50% fruit/ 100% herbs/100% eggs
Waking hours at home: We are semi retired (confirm % estimate)


Back in the late ‘70s I packed up my new bride and set off for the wilds of…Western Sydney! Well it was a little bit wild back then. The estate had no shops and no public transport but the housing and the loans were cheap and so we found ourselves on a 600m² block with an east-west facing, brick veneer, 3 bedroom house.

After many threats to head bush we are still here, concentrating on living as self-sufficiently and sustainably as we can in the suburban environment. Here are some of the things we are up to –

We grow as much of our own veggies as we can organically using open pollinated seed, our own where we can. We make seed raising mix using worm castings, sand and cocopeat, once the seedlings are up we pot them on into newspaper pots and then plant them out when they are ready. I have developed a spreadsheet that follows a two weekly sow/pot on/plant out rotation. We have a small greenhouse that we use to raise seedlings and grow a bit of out of season stuff during winter. During summer we place shade cloth over the greenhouse and continue to use it to raise seedlings in.

I get in grass hay from a local supplier and let it get worked over by chooks and then use it as mulch. We have 14 beds, half are about 2 metres x 1 metre and half are 3 metres x 1 metre. We fertilise mainly using a chook tractor which is designed to sit directly over a veggie bed with some compost and comfrey extract also used. The chook tractor spends two weeks on each bed twice a year. The chook tractor has 2 chooks in it and we can get 2 eggs a day but we also have the “Retirement Village”, a shed where the non-productive chooks still do meaningful work by digging over the hay and turning it into mulch.

We also have fruit trees – a mandarin; lemon, lemonade and orange tree, half a dozen bananas in a banana circle, a mulberry tree, native plum, olive, feijoa and two lime trees (one Tahitian, one Kaffir) and more recently a couple of apples, a nectarine and macadamia nut. The apples, limes and macadamia are in the front yard in a fruit tree circle based around a worm tower. The fruit tree circle also has a dwarf lemon and a curry leaf tree.

We have six recycled steel bathtubs; one which we use as a fishpond but also grows water chestnuts and a similar plant called Arrow with decorative arrow shaped leaves. Another houses our worm farm which helps us process our veggie waste and provides castings to make the seed raising mix with. Two are in the front yard as wicking beds growing insectary plants and pumpkins etc. and the final two are in the back yard treating our wastewater as a constructed wetland.

In terms of electrical power, we have a grid connected 1 kW photovoltaic system that has been in since the start of 2009, but we have had a standalone system in place for over 25 years. This is what he had and how it operated up until November 2016 –

The system was originally based on a SolarexX44 BG photovoltaic panel, about 17 years ago I added a BP Solar Panel to the system which gives a peak output of about 2.5 amps and added a third solar panel, a Photowatt International PW 750 which on a good day can pump out 4 amps which about doubled my generation capacity.  It cost a bit at AU$600 but was the best cost per watt unit that I could afford. All of these units continue to pump electricity into my batteries whenever there is light shining on them, they require little maintenance, don’t annoy the neighbours and have no on-going costs associated with them. The latest addition has been 4 x 80 watt Solarex panels, donated by my brother a few years ago and I could charge up to 25 amps.

The 12VDC is stored in two battery banks of 4 x 220 amp hour 6 volt batteries, wired to give 440 amphours of storage in each bank. One bank powers the house lights and the other powers a 12 volt fridge which provides our main refrigeration in the house. Unfortunately the fridge does consume more than I thought so we bought a couple of 130 watt Sharp panels to power the fridge and allow more power back into the house system. The stand alone and the 1k watt back-to-the-grid system have reduced our electricity bill to almost nothing.

Due to the vanishing of the AU60c feed in tariff we have decided to go off grid. The bottom bank of batteries (worn out) has been decommissioned as have the older panels with the Sharp panels being retained and a series of 4 x SolarE 130w panels and 4 x Stion 140 watt thin film panels have been installed, (soon to be increased by another 8 Stion 140 watt panels). To store the power generated two new battery banks each composed of 19 x 1.2 volt 100 amp hour brand new nickel iron batteries have been installed along with a Victron 50 amp MPPT and 3 kW inverter plus other electronics.

We also have a number of solar cookers including a solar oven which we can use to cook bread the year ‘round (it just takes a bit longer in winter.). Another type of solar cooker uses flat mirrors on a frame like a slice out of a parabolic dish to focus the sunlight on the bottom of a black painted stainless steel pot (good for frying and steaming). Due to the way we plant now we don’t produce a lot of excess veggies but we have a solar drier to process any excess we do get.

I have put together a rocket stove, which is used to cook with a wok and burns small twigs efficiently to produce plenty of heat for cooking. Small twigs are available for the taking in our area, they literally fall off the native trees in the parks and roadsides.

We have a over 10,000 litres of water storage – 2 x 2500 litre galvanised steel water tanks on the back of the garage and a newer plastic 5500 litre tank at the side of the house and a newer 500 litre water butt off one of the sheds. The larger tank is connected to a 12volt pump which allows us to irrigate the various food gardens.

To reduce our water usage for growing food we have been progressively implementing low tech, low water use irrigation options over the last 6 years. These include ollas made from scratch (by me as a potter), ollas made from commercial plant pots, deep pipe waterers, porous hose, buried pipe waterers, buried capsule waterers, wicking beds and self-watering containers.

It is really an attitude more than anything else, looking at the reduce part of the trio of “Reduce, Reuse and Recycle” and have added “refuse” to the trio – refuse packaging and other stuff we don’t need. We keep asking, “How can we do this ourselves, with what we have on hand?”. It is a journey really and we are still working on how we can become more self reliant and sustainable and hold a “Directors” meeting every October to look at how we are travelling on the plan and what changes need to be made and what the priorites should be for the coming year. We are also contributors to Permaculture Sydney West of which I am president.

We open every year for sustainable house day and permaculture day and try and get the word out that more sustainable living in the city is not only possible, it’s fun! For more visit underthechokotree.com

See David Holmgren's main website http://holmgren.com.au/