Kohi Kohi 2020

House Notes – Kohi Kohi

Faced with the prospect of becoming empty nesters, the Melbourne based couple decided to take on a trifecta challenge – making a sea change, downsizing and building a sustainable house that generates more energy than it consumes.

Built by Sociable Weaver, Kohi Kohi (Maori for coming together) combines a small footprint (what we call ‘right sizing’) with a very high energy efficiency, resulting in zero net household energy consumption.

The home started with passive solar design – oriented to the North (over 75% of the double glazed window area is on the north facing wall) combined with carefully designed awnings that allow the sun to penetrate up to 6 metres into the building in winter, while shading the harsh summer heat. This is combined with thermal mass including advanced ‘Phase Change Material’ in the ceilings, concrete floors & internal recycled brick walls, to almost eliminate the need for heating and cooling, with a NATHERs rating of 8.9 stars.

The 5.3kW PV solar power station on the roof not only generates more energy than consumed (even in winter), but also allows a long range Electric Vehicle to be trickle charged – allowing up to 500km per week of emission free and cost free driving!

The floorplan is not only compact (115m2 + 28m2 garage), but also incorporates a flexible layout, for example:

  • ‘Flexi-space’ primarily used as rumpus/ sewing room, quickly converts to 2nd bedroom by way of folding/ wall bed; space can physically separated by internal curtains (future installation)
  • Study converts to 3rd bedroom with Folding couch
  • Garage includes laundry space with Drying area (fully insulated, eliminating the need for an electric clothes dryer)
  • Water tank (11,075 litres) supplies Toilets/ Garden and is sited to provide wind protection & allow future landscaping and elevated viewing platform to take in sea views
  • Entry hallway acts as an Airlock and windbreak from the outside elements

Built with local materials where possible (for example, Tapware and tiles are locally made), low-toxicity paint and finishes. Ceiling fans supplement the natural flow-through ventilation. Water and air are heated by highly efficient Heat pumps. Lighting is Surface mounted efficient LEDs to avoid holes in the insulated building envelope.

This home is one of 12 homes open for Sustainable House Day from The Cape, a sustainable housing estate in Cape Paterson, Victoria. www.liveatthecape.com.au

Sustainability Features

Years Open
2020
ENERGY AND WATER EFFICIENT FEATURES
    • Energy efficiency:
    • Efficient lighting
      Efficient appliances
      Energy monitoring
    • Passive heating cooling:
    • Cross ventilation
      Deciduous planting around house
      External planting
      Passive solar designed home
      Shading
    • Active heating cooling:
    • Ceiling fans
      Heat pump
    • Water heating:
    • Hot water heat pump
    • Water harvesting and saving features:
    • Rainwater storage - Above ground
      Low flow shower heads
      Low flow taps
    • Average water consumption per day:
    • <100kL
    • Energy Efficient Lighting
    • LED lights throughout
      Natural daylight
    • Window Protection:
    • Awnings (external)
      Deciduous tree/vegetation
      Drapes/curtains
      Eaves
SUSTAINABLE & RECYCLED MATERIALS
    • Sustainable materials:
    • Phase Change Materials- Ceiling
    • Recycled and reused materials:
    • Bricks
      Excavated earth
INSULATION SPECIFICATIONS
    • Insulation Type:
    • Under-roof
      Ceiling
      Internal walls
      External walls
      Floor
    • Ceiling Type:
    • PCM- Phase Change Material
    • Ceiling Rating:
    • R6
    • Floor Type:
    • Wafflepod
    • Floor Rating:
    • R2.7
    • Under Roof Insulation Type:
    • R1.9 Blanket
    • Under Roof Insulation Rating:
    • R7.0
    • Internal Walls Insulation Type:
    • Reflective insulation
    • Internal Walls Insulation Rating:
    • R2.0
    • External Walls Rating:
    • R2.7
    • External Walls Type:
    • Reflective insulation
RENEWABLE ENERGY SPECIFICATIONS
    • All-Electric Home?
    • Yes
    • Renewable energy used:
    • Solar PV grid connect
    • Average Daily Energy Consumption:
    • 4kWh
COSTS AND COST SAVINGS
    • Total cost of home when constructed:
    • $455,000 2020
    • Estimate of annual savings:
    • $7000
HOUSE DESIGN SPECIFICATIONS
    • House Size
    • 152
    • BAL Rating
    • BAL – 12.5: Ember attack with heat up to 12.5kW/m2
    • Roof
    • Metal (Colorbond)
    • Wall Materials
    • Brick veneer
      Lightweight construction (timber frame)
      Metal (Colorbond)

    • Wall Materials
    • Ply
    • Window and Door Types
    • Clerestory windows
      Double glazing
      Low-e, films
      Pocket doors
      Sliding windows/doors
      Tilt and turn
      180 degree opening doors
    • Universal design accessability
    • Adaptive design
      Multi-generational
      Universal access
    • Universal Design Features
    • 80cm minimum door opening width
      Hobless showers
      Lever handles for doors (no knobs)
      Loud doorbell/connected to flashing light
      No Corner cupboards
      Ramps and path gradients must be less than 20:1
      Semi recessed basins
      Shower head on rail for various heights
      Tapware to be easily accessed from outside the shower

    • Universal Design Features
    • Extra fixings in walls for future grab rails in ensuite
    • Number of bedrooms
    • 2
    • Number of bathrooms
    • 2
GARDEN AND WASTE REDUCTION
    • Garden / Outdoors
    • Bee keeping
      Bee hotels/friendly
      Chickens
      Composting
      Edible garden
      Frog friendly
      Greenhouse
      Local indigenous plants
      Orchard
      Native plants
      Water wise plants
      Wicking beds
    • Waste Reduction Practices:
    • Compost all food scraps
      Make jams/conserves
      Pickle and preserve food
      Recycle
      Repair
HEALTHY HOME FEATURES
    • Healthy home features
    • Carpet free - tiles/concrete/timber flooring throughout
      Cross flow ventilation
      Indoor plants for air filtration
      Low VOC paints/sealer/varnish
      Natural light and ventilation
      Natural oil sealer/finishes
      Wax based sealer/finish
Location
Cape Paterson VIC 3995
    • Housing Type:
    • Standalone House
    • Project Type:
    • New Build
    • Open with support of
    • The Cape Sustainable Development
    • Builder
    • The Sociable Weaver
    • Designer
    • The Sociable Weaver

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