Sustainable House Day, Islington, NSW

This home is an inner-City retro-fit in progress  that has tripled living space with a minimal increase in the original impervious footprint of lot.  

In the last billing-quarter this property generated 100% of its power use.

Retrofit:   Designed by owner. Owner builder licensed.

Unique Sustainable Elements featured in this home

Rebuild: footprint considerations
Conversion of a 100 year old small 2 bedroom cottage with poorly sited out-buildings to a 3-4 bedroom house with more living/storage space plus a studio shed; increasing accommodation from suiting 1-2 adults to a potential 4-5 adults with minimal increase of the building foot print. The main house has only 1 bathroom (2 toilets); a deliberate move away from the bathroom-intensive developments currently in fashion. The kitchen space is also very compact, using all opportunities for shelving and storage under the new stairwell.

Climate adaption and servicing considerations
The house is on a low-lying area and with climate change predictions for larger and more frequent rainfall/flooding events (medium-long range sea level rise predictions notwithstanding) the house was re-piered from 300mm to 1100mm clearance (well above the 20mm extra required by Council for new work!). This also provided benefits for servicing, storage for salvaged building materials as well as opportunity for grey water-system fall, and possible space for a composting toilet system.

Water Harvesting
The first set of water tanks has been installed: 3 tall circular tanks in a bank collecting water from the shed 2800L capacity.
Next: these will be connected to another bank of tanks off the main house to function together as one bank, with a ‘rainsaver’ pump.  This will be plumbed into the house toilets and laundry.
Next: Pervious trenching with rock and ag-pipe across the yard will absorb tank-overflow before connecting to the stormwater system.  
Next: Greywater filter beds to be built to take water from the raised house through beds decreasing in height to the back garden in the north.

Special Garden Features
Maximum yard space in the north of the property created for food gardens and chickens when the building work is completed. Native trees are establishing on the street verge with a view to extension of mulch and native understorey until the grass is gone. Sediment is also swept up and collected from the street gutter before reaching the drain/creek and added to the native garden.
Next: more tall trees will be planted on the western side (front) including avocado. No tall trees to be planted in the north.

External Walls
The house is mainly clad with recycled weatherboards and wall framing is from recycled hardwood and oregon. These materials were either retained from the demolished sections of the original house or purchased from building demolition yards. Light coloured paint on main house.
All walls are lined with ‘air cell’ R2.9 reflective insulation.

Internal Walls
R1.5 batt insulation in all internal walls in addition to 'air cell' insulation. Recycled timber liner boards (recovered from this and another demolition) have been used in a third of the wall linings.

Roof
Zincalume iron roof, ‘air cell’ R2.9 reflective insulation. Long eaves on the upper story and northern wall.

Floor
Existing hardwood floors sanded and restored in original part of house. Recycled hardwood floorboards used in extension downstairs.  Natural oil finish.
Next: Sisal grass carpet in upstairs extension may be installed by the time of the open day.

Window Treatments
Most windows recycled single-pane glass. A find of 8 x same windows dictated the design of the lower storey northern wall. Upstairs windows have been made locally using recycled hardwood and oregon.
Next: wall-length curtains on high rails for winter months (to be removed in summer)

Energy
1kW grid-interactive power system. Energy bill from last quarter recorded neutral use with a bill credit.  Small fridge. Minimal electric appliances. Low-energy lights throughout.

Heating & Cooling
Large eaves on the upper storey and northern face and minimal windows on western wall.  North-east facing living room collects sun in winter. Upper rooms have windows and roof vents.  The outdoor verandah has been placed on the shaded south-eastern corner of the house for summer use. The rebuild also saw the replacement of the original laundry and bathroom that closed off the northern face of the house with a sunny living room.
Next: the existing air conditioner poking out of the front window is to be removed when replica sashes are built.
Next: natural gas heater for use on coldest nights when gas connected. Residents conscious of wearing more clothes and closing off rooms to minimise usage.
Next: draft sealing around roller door on shed
Next: shade hoods built over remaining windows not under the eaves

Water Heating
Solar – evacuated tubes with electric booster on manual setting bracketed to north western face. >