The Greeny Flat 2021

This profile is written and maintained by the homeowner, architect, or builder.

House Notes – The Greeny Flat

The “Greeny Flat” began as a full-scale living experiment to see if it’s possible to build a small, comfortable, healthy, energy positive, low-maintenance, fire-resistant, water-efficient, elderly-friendly infill house at an affordable price.

Set on a beautiful site near downtown Mittagong the Greeny Flat features passive solar design; durable, low-maintenance materials, renewable energy systems, rainwater catchment and reuse, healthy materials and systems, local and reclaimed materials, energy efficient appliances, water efficient fixtures and landscaping, and is located within easy walking distance of services, bushland, and public transportation.

The Greeny Flat has been occupied for over ten years now during which time we have closely monitored the energy performance, comfort levels and water usage. We’re delighted to report that, over that time, we have exported two-and-a-half times as much power to the grid (34,246kWh) as we have imported from it (13,651kWh) using just a 3kW solar power system. We have also managed to use two-and-a-half times more tank water (323,784L) than town water (122,456L). The little house has proven to be a delight to live in, comfortable, cheap to run, easy to clean and maintain and we couldn’t be happier with the results of our “experiment”.

A few years we also been renovated and did a deep-energy-retrofit on the old fibro cottage next to the Greeny Flat. That cottage is also now energy positive, comfortable, inexpensive to run and delightful to live in.

More information about both homes is available at our website at greenyflat.com.au

SUSTAINABILITY FEATURES

Years Open
2021
ENERGY AND WATER EFFICIENT FEATURES
    • Energy efficiency:
    • Draught proofing
      Efficient lighting
      Efficient appliances
      Energy monitoring

    • Energy efficiency:
    • Occupant behaviour. We operate the house carefully to keep it comfortable summer and winter and limit the need for any sort of active heating or cooling.
    • Passive heating cooling:
    • Cross ventilation
      Passive solar designed home
      Shading
      Thermal mass

    • Passive heating cooling:
    • Careful siting for solar access and protection from cold winds in winter. Long axis E-W to provide opportunity for more N glazing. Large windows on N, very small windows on W. Correct size N roof overhang to let in winter sun and keep out summer sun. Careful planting and landscaping so as not to impede solar access.
    • Active heating cooling:
    • Ceiling fans
    • Water heating:
    • Solar hot water (evacuated tube)
    • Water harvesting and saving features:
    • Rainwater storage - Above ground
      Low flow shower heads
      Low flow taps
    • Average water consumption per day:
    • 0.1kL
    • Above ground rainwater storage Type:
    • Slimline poly tank
    • Above ground rainwater storage Size
    • 5000L
    • Energy Efficient Lighting
    • LED lights throughout
      Natural daylight
    • Window Protection:
    • Eaves
      Honeycomb blinds
SUSTAINABLE & RECYCLED MATERIALS
    • Sustainable materials:
    • Passive Solar Design. Good level of air-tightness (3.5ACH50 confirmed by Blower Door Test).
    • Recycled and reused materials:
    • Concrete
      Doors
      Insulation
      Paving
INSULATION SPECIFICATIONS
    • Insulation Type:
    • Under-roof
      External walls
    • Under Roof Insulation Type:
    • Insulated panels
    • Under Roof Insulation Rating:
    • R4.0
    • External Walls Rating:
    • R2.2
    • External Walls Type:
    • Bulk – polyester
RENEWABLE ENERGY SPECIFICATIONS
    • All-Electric Home?
    • Yes
    • Renewable energy used:
    • Solar PV grid connect
    • Size of PV system:
    • 3
    • Average Daily Energy Consumption:
    • 2
COSTS AND COST SAVINGS
    • Total cost of home when constructed:
    • $131,000 (2013)
    • Cost estimate of sustainable home/features:
    • $240,000
    • Estimate of annual savings:
    • $1000
HOUSE DESIGN SPECIFICATIONS
    • House Size
    • 57
    • BAL Rating
    • No BAL rating requirements at time of construction
    • Roof
    • Insulated panel (sandwich panels)
      Metal (Colorbond)
    • Wall Materials
    • Lightweight construction (timber frame)
      Metal (Galvanised)
    • Window and Door Types
    • Casement
      Double glazing
      Low-e, films
      Sliding windows/doors
    • Universal design accessability
    • Adaptive design
    • Universal Design Features
    • 80cm minimum door opening width
      Hobless showers
      Lever handles for doors (no knobs)
      Slip resistant flooring
    • Number of bedrooms
    • 2
    • Number of bathrooms
    • 1
GARDEN AND WASTE REDUCTION
    • Garden / Outdoors
    • Composting
      Edible garden
      Orchard
      Water wise plants
    • Waste Reduction Practices:
    • Book exchange/library
      Compost all food scraps
      Recycle
      Repair
      Take own containers to the supermarket and for take away food
      Swap with friends and neighbours
      Waste free/reduced construction site
HEALTHY HOME FEATURES
    • Healthy home features
    • Airtight house design
      Automated ventilation system
      Carpet free - tiles/concrete/timber flooring throughout
      Cross flow ventilation
      Formaldehyde free cabinets
      Low VOC paints/sealer/varnish
      Natural light and ventilation
Location
Mittagong NSW 2575
    • Housing Type:
    • Granny Flat
    • Project Type:
    • New Build
    • Builder
    • Andy Lemann
    • Designer
    • Andy Lemann

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