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16 x 5kW polycrystalline solar panels chosen for use to expose to sunlight and capture energy. Polycrystalline type has higher temperature resilience without significant decrease in performance and efficiency, compared to monocrystalline which has risk of malfunctioning in extreme heat. 5kW system chosen to accomodate for electrical energy usage for family of 4 in one house, covering appliances’ energy such as LED lighting, computer charging, TVs and other appliances. (Tesla) Battery stores excess energy during nighttime to prevent electricity from transferring to the grid for later usage. Occupants can reduce the energy bill in this way. Solar panels tilt at 30° for winter and summer solar gain maximisation.

Tesla powerwall battery to store surplus energy instead of giving excess energy to the grid. Install central inverter to change phase of electricity from acquired solar energy before integrated use. This will not be blocked by shade due to considered distance from tree plantation.


Gas system: Gas connected to gas powered stove as even though gas is currently quite cheap in Victoria; the client has agreed to be saving where possible as expenses have been prioritised for other system installations. Currently the gas lower carbon footprint than electricity in Victoria due to generating electricity from brown coal, which has high wastage production. The use of gas in this house has been minimized; only used for kitchen stove utilities.

Rainwater tank with wet system has been chosen so as to allow clients to maximise efficiency of their use of water and in doing so, reduce water bills over the long-term. Sediment filter is required however, to allow the water to be reused for washing/flushing etc. As for drinking water, this will come from the main water supply as to reduce risk of disease or harmful bacteria entering drinking water source for the clients. Stored water will also be heated via solar heat gain and used for hydronic slab and panel heating. This is intended to maximise beneficial use and redistribution of rainwater hence reducing heating and water bills for running costs.

Rainwater catchment system; as installed wet system. Water remains filled in downpipes and requires constant filtration device with maximum aperture of 0.9mm to be mounted above tank overflow level.

Solar hot water evacuator tubes has to face north and can be tilted 57 °to optimize winter performance on the flat roof. Fewer tubes installed compared to flat plat connectors, to assist with efficiency of overall solar gain for both electricity and solar hot water system (as solar gain is required for both electricity (via flat plate collectors) and hot water for hydronic slab heating (mainly via evacuator tubes).

Rainwater tank type Slimline type water tank; maximise space efficiency in the west side of the yard and provides modern feel and aesthetic. Can hold up to 450 to 5000L of storage.

Evacuated tubes can absorb solar heat effectively than flat plate collectors due to its cylindrical shape gathering solar access from more rounded angles and higher surface area. Rebate from the government is offered to this brand to encourage more people to use these types of hot water systems. Image retrieved from

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evacuator tubes (on roof)



Sewage connections must not be installed with 90° connections as non-right angles will reduce risk of waste clogging the pipe. Pipes to be trenched with minimum cover of 300mm below surface ground level. Drain-waste vents with minimum 1.65% gradient for roof level is required, to prevent accumulation of unpleasant odours and gas toxins hence reduce risk of explosions or damage to the services, as well as maintain neutral air pressure in the pipes. Downpipes: 1 required at least per every 9 metres. Excess overflow from rainwater tank is to be discharged to the junction pit then to legal point of discharge. Wet system installation for green roof purposes. Rainwater collection: For rainwater storage, a family of 4 uses on average 300 to 360L of water per day. This includes uses such as showering, toilets, flushing, washing, gardening and other uses. Minimum storage of 2000L is to be installed to cater for this average requirement. Collected rainwater will also be used in the heating strategy, providing solar hot water to generate heat in hydronic panel heaters and hydronic inslab coil heating for the residence.

Schematic diagram of DWV unit function

Right angled connections can cause clogging of waste in the pipes. Acute or non right angles prevent this from happening and allow waste to flow effectively.

Greywater system: Waste water treatment. Greywater is collected from showers/baths/toilet cubicles/washing machine but not collected from the kitchen due to harmful minerals and detergents. Greywater will flow into the filter for treatment and redistributed via water pump to use for toilet flushing and green roof watering for the greywater tolerant plants. Stormwater connections require connection to at least one junction pit and legal point of discharge.



Hydronic in-slab heating coil pattern

Heating strategy - Active Hydronic Choice for this heating system for in-slab heating allows for low maintenance requirements, control valve for every panel in zoning where necessary and use of hot water from filtered rainwater system. No risk of unpleasant odours or drafts which in turn will not worsen asthmatic conditions. The hydronic slab system is installed as it prevents production of drafts and heat is more evenly distributed throughout the floor. Heat is collected from evacuator solar panel tubes and enters the hot water system to produce heat. There is expensive capital cost associated with the system but a lower running cost over long term usage expenditure, as the house also benefits from maximised solar gain for electricity into hot water systems. By utilizing rainwater collection and solar hot water, this can reduce reliance on main supplies of water, reducing water and heating bills over long-term. Individual zoning via thermostat control can be included.

Heating strategy - Solar air Trombe wall (Solar air Trombe wall schematic diagram; see trombe wall section for more detail. ) Trombe wall acts as a passive heating system which involves glazing over walls and due to inclusion of vents that allow circulation of heat into the house and cool air faciliatated out of the house during winter. Installed on the west side of the kitchen/living and single bedroom area to allow for heating where morning sun heat is not as effectively gained as other parts of the house. The clients have also stated they are prepared to dress warmly or as appropriately for the climate should the need arise.

The disadvantages is, however, that longer duration of time is required for the heating process as pipes need to radiate heat into the concrete slab first. Concrete however can store the heat, once it is transferred, for longer duration than timber flooring or gas ducted/space heating.

Also refer to water supply plan for connection of HWS to hydronic panel heaters (right; showing location of hydronic panel heaters with connections).

Section of in slab heating for suspended slab.

Solar hot water evacuator tubes to assist hydronic panel system heating diagram

Zoning In-slab hydronic heating coils installed to provide heating to hallway and joined kitchen/living areas. For bedrooms, use hydronic space panel heaters for shorter heating duration to be used when necessary. No heaters required in bathroom but there is room for smaller portable electric heaters which can be installed in the future when needed and attached to a powerpoint generated by solar electricity. Hydronic water panel heaters have a heating response time of approximately 30+ minutes and low maintenance requirements. Regarding health requirements, hydronic in-slab heating and the panel heaters have been chosen for installation to reduce draft hence assist with the client’s child’s asthma. Use hot water system to produce heat for hydronic panels and maximising benefits from the 2000L water tank.



Solar-air cooling Trombe wall: installed on west side of kitchen/living area to be the main aspect of passive heating/cooling during winter; as clients spend majority of their time in this area. Vents for trombe wall are readjustable according to the weather/season (see heating section for how to set the trombe wall for passive heating). The clients, being environmentally energy conscious, have decided to have this wall type for the west side of their home and vents adjusted (refer to wall diagram on left) for allowing heat to escape through the vents for passive cooling. Cooling strategy For passive cooling, cross ventilation, window openings, and trombe wall vent circulations can be applied. Active cooling can be used when required (if passive cooling strategies are not enough); fans with reverse cycle option mode can allow air movement to circulate. With adequate cross ventilation and insulation, fans can be enough for cooling comfort. However, fans only create air movement that creates a cooling effect but may not actually decrease the temperature inside a specific zone much. Evaporative cooling system is chosen for consideration to low energy use, low running cost (despite moderately high capital cost) and ducted for individual zones. The system cools air but increases humidity which can be effective in Melbourne’s drier climate. In the occasion that the weather is too humid, the clients have agreed to use ceiling fans (see electricity supply section for ceiling fan type) and passive cooling with cross ventilation throughout room openings, combined with inclusion of trombe wall system. It is connected to the main water supply to avoid build up of foreign material or bacteria in the system unit which can come from rainwater supply. This also greatly reduces the risk of developing unpleasant odours in the unit. This will ensure reduced maintenance cost and reduce the chances of rainwater system faults within the evaporative cooler unit. Evaporative coolers will draw outside air into the unit which then runs through wet filter pads to convert warm air to cool air. This increases humidity but moisture can be expelled by having windows/doors open. Some draft will be produced however, the clients have agreed to use this as an alternative to refrigerated cooling as refrigerated cooling and ducted systems will be costly in the long term and produce high greenhouse gas emission.

BRIVIS evaporative cooler

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DESIGN FOR RESILIENCE ‘Resilience’ includes taking into consideration, the capacity of a system’s ability to deal with change and continue to develop. Designing for resilience for modern homes is important these days due to changes in overall climate, temperatures, sustainability issues. The recent effects of global warming to the economy and infrastructure poses a threat; designing for resilience coupled with green/eco-design features can help minimise 3 main concerns, drought/power outages/heatwaves, against Australian infrastructure.

[Proposed earth-covered shelter/fireproof bunker]

HEATWAVE - GREEN ROOF Extensive green roof option allows for additional insulation and also an option to provide more plantation for the dwelling. In summer it can reduce up to 40% heat and in winter, retain 13% more of heat. It has relatively high fire-resistance for the roof and can cause increase in humidity and oxygenation in the air. This is mostly beneficial during heatwave. Due to additional insulation, there is improved thermal performance. Unfortunately the area of green space cannot be increased on the roof unless a compromise is made (as in, removal of evacuator solar hot water tubes and flat plate collectors). Passive shading via landscape plantation alongside with additional inclusion of trombe walls can assist with allowing heat to escape from the house hence assisting with coping with the heatwave. Small double-glazed windows have been applied which can potentially assist with comfort during warmer nights due to increased insulation. The chosen plantation species are relatively adaptable to drought or warm temperatures.

Proposed earth-covered shelter: As the temperature below 1m of ground for Melbourne is approximately 16 to 18°C, installing a fireproof bunker could prove beneficial against heatwaves in Melbourne. The bunker also allows for extra storage space for food/ water/necessities supply. It can serve as a temporary safety and shelter until a heatwave subsides, however it will be expensive to build so care must be taken into consideration of capital costs for this feature. (See altered site plan with proposals below for area used for bunker)

POWER OUTAGE - SOLAR POWER SYSTEM The house has an installed solar power system for electrical needs. To last throughout a temporary power outage, an extra battery may be applied to allow for more electricity storage hence allow the power to last several days longer. DROUGHT - RAINWATER SYSTEM REQUIREMENTS In the event of drought, the rainwater tank system may only be able to provide a short-term source of water hence more improvements could be necessary (see improvements section)


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IMPROVEMENTS Insertion of green walls as added measure to counter heatwaves could have been considered however this could run the risk of decreasing thermal mass and insulation properties of the house greatly as it would mean having to compensate a specific amount of area of the reverse brick veneer or trombe wall feature. Increased roof space for ventilation and higher amount of reflective foil insulation can reduce heatwave effects. External shutter installation could also be added to reduce heat gain from glass during summer months making passive cooling systems more effective. With regard to droughts, a pond or pool with natural filter system could allow for higher humidity levels surrounding the house and also provide drinking water if filtered through a purchased LifeStraw Steel filter. It is also a good option to consider, especially for asthmatic patients, should the client wish to install a swimming feature. To prepare for catering for drought, the liter capacity of the rainwater tank could be increased, or additional tanks can also be purchased. In under very serious circumstances and only if expenses allow for it, a moat may be installed around the house, including added emergency water filter systems. Due to having large open space for the backyard north of the house, earth-sheltered extension could be constructed, acting as a type of fireproof bunker during extreme droughts. Additional awnings or louvres on the east side could help with shading systems against heatwaves and heat gain in the daytime when required.


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Environmental building systems project  

ABPL20036 University of Melbourne #831400

Environmental building systems project  

ABPL20036 University of Melbourne #831400