HOUSE SIZE

428 m2 including first floor void area

BAL RATING ROOF

N/A

WALL MATERIALS

Combination of:
Timber frame with external brick veneer
Timber frame with external timber cladding
Timber frame with external brick veneer and internal brick veneer
Timber frame with external timber cladding and internal brick veneer

WINDOW AND DOOR TYPES

Cedar timber frames on all external windows and doors. Locally manufactured by Pickering Windows. (Local suppliers were used wherever possible and delivered excellent results.)
All double glazed, low air leakage. Some conventional awning and some Tilt/ Turn where advantageous.

Low E coatings specified for sun control east and west, and for thermal loss minimisation to the north.
Doors are all multi-point locking for reduced leakage.
Double glazed windows typically: U-Value=2.6, SHGC=0.50 (Before Low E coating.)
The 1.5 m2 motorised louvre uses double layer glass with a 0.2mm vacuum gap and low E coating to achieve good insulation performance and low air leakage.

UNIVERSAL DESIGN FEATURES

Split level house with lift between basement ground and first floors. Provision for wheelchair access to the main living area via external path, then lift access to the main bedroom/ bathroom.
Corridors and staircases are wide allowing for easy access.
Layout allowed for sufficient space to accommodate comfortable step rise/ run and generous step width as necessary for easy stair use.

NUMBER OF BEDROOMS

3

NUMBER OF BATHROOMS

2 bathrooms with toilets plus an additional toilet

Sustainable materials:

The Red bricks with 1956 Olympic rings from the house demolished on this site were cleaned by the owners for use in the new house. Additional second hand bricks were purchased from Melbourne.

Stairs and feature doors crafted from upcycled Messmate timber. (Stairs by Amadeus at Alpina Joinery and doors by Otway Builders).

Wood flooring in pre finished engineered wood with 4mm veneer of wood over ply backing. (Oslek “Wormy Chestnut” supplied by BM Floors and Llaid by Otway Builders).

INSULATION TYPE & LOCATION:

Slab: Polystyrene board under most of the slab but not under the beams. Perimeter of the slab is fully insulated. R1.8 nominal overall target.

Walls: R2.7 Bulk fill in stud frame with 15mm Foilboard facing under external cladding.  Additional Foilboard layer on inside of frame in some areas including behind internal brick. No separate air control layer.

Ceiling/ Roof: Galvanised roof deck over reflective roof blanket and bulk insulation. R4.0 Bulk plus R1.3 Roof Blanket.

Windows/ doors: All double glazed, timber frame, low leakage. Low E coatings - specified for heat control east and west and for heat loss minimisation to the north.

A key design principle was that no piping and as far as possible, no cabling was to be run in the external walls or ceiling, thus helping to ensure the continuity of this critical insulation envelope. This was facilitated by the provision of internal riser ducts and cavities, so that with careful planning, piping and cables could be hidden whilst remaining inside the house envelope and avoiding disruption of the external walls. This greatly reduced the need for sealing of penetrations through external walls and ceiling. Importantly the building team understood and carefully followed this requirement.

ALL-ELECTRIC HOME?

Yes

ENERGY STAR RATING:

NatHERS Rated by: F2 Design 7.3 star
(Originally 7.8 star before rationalisation of insulation details.)

RENEWABLE ENERGY USED:

Solar PV

SIZE OF PV SYSTEM:

10kW

SIZE OF BATTERY:

13.5 kWh (Powerwall 2) (On order but not yet installed as at Aug 2021)

ENERGY EFFICIENCY:

Eg. draft proofing, LED lighting appliances etc.
Draft proofing: (3.0 ACH @ 50Pa Blower door test result) Winter performance was already seen to be good and no drafts were evident to occupants so no attempt was made to further reduce leakage. This level of leakage was also considered beneficial to avoid complications in the use of direct kitchen exhaust extraction rather than recirculation with filter.
LED lighting throughout.
Lighting automation for convenience and efficiency.
Heat pump dishwasher.
Heat pump clothes dryer.
Clothes washer uses hot water from the efficient house supply or cold as required.

PASSIVE HEATING COOLING:

North facing aspect to maximise solar collection (Passive Solar).
Large amount of thermal mass to slow the daily rise and fall of temperature. (Mid winter overnight drop is approx 1 deg C without heating - ie 22 to 21 deg C internal with 5 degrees C outside.) (Internal brick walls plus polished concrete floor.)
Heat Recovery Ventilation (HRV) serving all areas of the house. HRV automatically uses cold outside air for house cooling when needed.
Automatic motorised windows for night time cross ventilation/ cooling including large louvre window to south west and high windows in bedrooms and living.
Automatic external shading to north and east for summer sun control.
Heat shifters to transfer heat from the north to south end of the house. Warm air is drawn via high level collection slots in the two north facing rooms. Variable speed fans controlled automatically according to the thermal conditions.
Ceiling fans in all bedrooms and living room.
Below ground cellar enables storage of wine and produce at approx 20 deg C year round without need for active cooling.
PassivHaus design would have dictated a reduction in windows, plus increased detailing of insulation and much greater focus on air leak reduction to reduce need for heating/ cooling. Without these specialised requirements however, the house as constructed was less complex to build and is bright and airy. It takes maximum advantage of passive solar heating in combination with significant thermal mass, supplemented by high efficiency hydronic and cross ventilation for cooling and comfort.

ACTIVE HEATING COOLING:

Heat pump hydronic in the living room slab with a second zone in the south bathroom floor slab. The hydronic heating to northern living area is required only on heavily overcast days. Heat pump hydronic can also be used to cool the slab in summer if required.
Split system heating/ cooling is installed in upstairs bedroom but to date has not been needed to be used.
Hydronic heat storage tank is located in the basement. Water temperature is able to be kept relatively low since little room heating is required, thus helping to optimise heat pump efficiency. (29C tank set point)

WATER HEATING:

Sanden heat pump hot water. Storage tank in the basement.
Separate hot water recirculation loops to the kitchen and each of the two bathrooms allow hot water to be primed to the respective outlets without loss of water. (Displaced cold water returns to the cold water inlet of the storage tank.)
Provision has been made for future possible auto control of heat pump to enable operation only when excess solar PV output is available.

WATER HARVESTING AND SAVING FEATURES:

Water from all house and garage roof areas feeds to underground tanks via a self cleaning cyclone filter. 25 k litre underground storage feeds all garden taps and toilet flush via high pressure automatic submerged pump. Mains water automatically takes over if tank is empty.
Calculations suggest that 10mm of rain will collect approx 5k litres to the tank.

ABOVE GROUND RAINWATER STORAGE:

600 litre additional tank on garden shed for garden usage

WATER HARVESTING AND SAVING:

Drip irrigation to some garden areas in place and planned to be extended. Cabling in place for future automatic control.

ENERGY EFFICIENT LIGHTING:

LED lighting throughout. (Most fittings supplied locally by Sonic Lighting.)
Wireless Z-Wave control modules installed for most lights which with a Fibaro HC3 Automation Gateway allows individual remote control, and monitoring of every light. Ten sensors around the house allow any group of lights to be switched on or off according to movement, light level, time or any combination. This has proven to be very convenient, a great safety feature for movement at night, as well as saving energy by helping to avoid lights being accidentally left on.

WINDOW PROTECTION:

A motorised “Operable eave” shades the main north windows. This avoids the compromise of fixed shading by allowing use of sun to be maximised or reduced in any season while preserving the outlook from the living area.
External vertical blinds protect the largest eastern windows from summer sun.

CAR CHARGING

Three phase power supply point available in garage for future use for charger (to be installed shortly at time of battery installation).

HEALTHY HOME FEATURES

HRV air filtering and healthy changeover of air. (Typical 8 or more whole of house air changes/ day.)
Multiple openable windows to enable cross ventilation and plenty of fresh air under favorable conditions for comfort and temperature control.
Generous natural light in every room (except basement!).
Kitchen exhaust fan exhausts direct to outside (ie not recirculation) and has auto closing flap to prevent air leakage when not in use.

COST ESTIMATE OF SUSTAINABLE HOME/FEATURES:

Hard to say since almost all aspects of the house contribute to the comfort, health and reduction of energy usage. Mostly conventional materials and techniques were used in construction but with special attention to leak tightness and continuity of insulation.
Some features such as HRV contribute to comfort and healthy environment but with little direct energy cost saving.
Achieving a result of zero net energy usage (and even energy export and/ or car charging) is a very important goal as part of our contribution to reduction in greenhouse gas emissions.

COST SAVINGS PA:

Est say $5,000 PA compared to conventional construction.
(Based on information from our old house.)

GARDEN / OUTDOORS:

Multiple productive garden beds for rotation of food crops. This includes four raised beds and six Biofilta “Foodcube” containers with water saving reservoirs in the base.
Apart from ornamentals, we also have multiple fruit trees including: Fig x 3, Apricot, Nectarine, Peach x 2, Pear x 2, Feijoa x 3, Lemon, Persimmon, Quince and Native Finger Lime.
We have foundations in place for future greenhouse to help extend our growing season.
All garden beds are mulched to reduce water usage.
Majority of weeding is done by hand with minimal use of herbicides.

WASTE REDUCTION PRACTICES:

All kitchen plant waste goes to our worm farm.
All garden green waste (except seedy weeds) to compost.
Trees and shrubs are chipped on site to provide garden mulch.