Thornleigh Passive House 2020

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Location
Thornleigh NSW 2120
    • Housing Type:
    • Standalone House
    • Project Type:
    • New Build
    • Open with support of
    • Australian Passive House Association
    • Builder
    • Red Cedar Constructions
    • Designer
    • Envirotecture

About Thornleigh Passive House

Sydney’s first certified Passive House!

This Envirotecture-designed, compact two-storey home replaces a defunct cottage. Nestled in between a busy road, a magnificent tallowwood and a train line the home will offer a haven of peace and quiet.

The insulated, air tight construction with heat recovery ventilation (HRV) system provide superior indoor air quality without the need to open windows (but you can if want).

The building form responds to the sun path across the site, maximising solar gain for winter while providing high levels of shade to keep cool in the summer months. The large north facing roof allows for a significant photovoltaic system, sufficient to be energy positive over the year.

The living spaces are orientated to enjoy the view of the tallowwood tree that is at the geometric heart of the site. The large ‘lift & slide’ doors provide an intimate connection to the rear yard and the deck wrapping the tallowwood. This seamless flow will work well when the weather permits and still ensure the visual connection when the weather is less accommodating.

The structure is a direct response to site conditions and the desire to preserve the tallowwood. The raised structure protects the root zone of the tree, and is thus lightweight, lacking thermal mass. This is less significant in a passivhaus than in passive solar however, as thermal mass still provides positive benefits the house has 10 internal water tanks to assist in regulating internal temperature.

The tanks act as a room divider, framing the entry, while also capturing the sun through a huge north facing window that has a retractable shading blind for summer sun control. The tanks will be filled after construction and are not connected to the other rainwater tanks, as the temperature of rainwater can be problematically low and poses a condensation risk if put straight into the building.

The house is compact with three bedrooms, a study/guest room for overseas parents and two bathrooms (no ensuite). The laundry houses the HRV and hot water tank as well as the usual functional items.

The cost-effective windows are uPVC with an aluminium external skin. Imported, they come triple glazed as standard – double glazing would be a special order and add cost!

The construction methodology allows for on-site construction while reducing the risk of damaging the air tight membrane. The final blower door test yielded a result of 0.35ACH50. This is well within the Passive House limit of 0.6ACH50 and compares favourably with the average for a new Australian home of 15.4ACH50; 44 times less leaky!

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SUSTAINABLE FEATURES

Years Open
2019
2020
ENERGY AND WATER EFFICIENT FEATURES
    • Energy efficiency:
    • Draught proofing
      Efficient lighting
      Efficient appliances
      Energy monitoring
    • Passive heating cooling:
    • Cross ventilation
      Passive solar designed home
      Thermal mass
    • Active heating cooling:
    • Ceiling fans
      Heat exchange ventilation system
      Split system airconditioner
    • Water heating:
    • Hot water heat pump
    • Water harvesting and saving features:
    • Low flow shower heads
      Low flow taps
      Drip irrigation
    • Average water consumption per day:
    • 46L/pp/d Sydney Water + ~ 46L/pp/d rain water.
    • Energy Efficient Lighting
    • LED lights throughout
      Natural daylight
    • Window Protection:
    • Awnings (external)
      Shade Sails
SUSTAINABLE & RECYCLED MATERIALS
    • Sustainable materials:
    • No steel structure. Timber structure used No concrete at all (screw piles for footings)
INSULATION SPECIFICATIONS
    • Insulation Type:
    • Under-roof
      Internal walls
      External walls
      Floor
    • Floor Type:
    • Bulk - polyester
    • Floor Rating:
    • R2.0 Greenstuf
    • Under Roof Insulation Type:
    • Insulated panels
    • Under Roof Insulation Rating:
    • R4.95 (total roof) PIR
    • Internal Walls Insulation Type:
    • Bulk – polyester
    • Internal Walls Insulation Rating:
    • R2.0 SoundSolution
    • External Walls Rating:
    • R2.75 (total wall)
    • External Walls Type:
    • 50mm PIR thermal insulation board
RENEWABLE ENERGY SPECIFICATIONS
    • All-Electric Home?
    • Yes
    • Renewable energy used:
    • Solar PV grid connect
    • Size of PV system:
    • 5.22kW
    • Average Daily Energy Consumption:
    • 1.8MWh generated / 1.9MWh consumed over the last 143 days. Net import : 138.2 kWh / 143 days / 4 people. 0.2kW
COSTS AND COST SAVINGS
    • Total cost of home when constructed:
    • $900,000
    • Cost estimate of sustainable home/features:
    • minus $22,000 compared to passive solar.
    • Estimate of annual savings:
    • TBD
HOUSE DESIGN SPECIFICATIONS
    • House Size
    • 180m2
    • BAL Rating
    • No BAL rating requirements at time of construction
    • Roof
    • Insulated panel (sandwich panels)
      Metal (Colorbond)
    • Wall Materials
    • Lightweight construction (timber frame)
      Timber

    • Wall Materials
    • Exterior wall is OSB board with membrane, 50mm PIR panel & fibrecement board.
    • Window and Door Types
    • Clerestory windows
      Tilt and turn
      Triple glazing

    • Window and Door Types
    • uPVC triple glazed with an aluminium external skin; air tight, imported from Europe
    • Universal Design Features
    • 80cm minimum door opening width
      Hobless showers
      Lever handles for doors (no knobs)
    • Number of bedrooms
    • 3
    • Number of bathrooms
    • 2
GARDEN AND WASTE REDUCTION
    • Garden / Outdoors
    • Composting
      Drip irrigation
      Edible garden
      Native plants
    • Waste Reduction Practices:
    • Compost all food scraps
      Recycle
      Repair
      Swap with friends and neighbours
HEALTHY HOME FEATURES
    • Healthy home features
    • Airtight house design
      Cross flow ventilation
      Heat recovery ventilation (HRV)
      Low VOC paints/sealer/varnish
      Natural light and ventilation
      VOC free paints/sealer/varnish

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