Eco-friendly Granny Flats

No matter what the design, transportable eco-friendly granny flats can be environmentally friendly by incorporating materials and building methods granny flat plans that are kinder to flora and fauna with less damage to the land.


If windows are on east and west side, put shading over windows and specify glass with a low heat transfer.

InsulationInsulation for Granny Flats

Make sure the home has well insulated floors, walls and ceilings to reduce heat penetrating inside on hot days and keep the cold temperatures out in winter. Installing energy efficient ceiling and wall insulation standard R3.5 rating can be upgraded to R4.0 for extra insulation against the elements.


Highly reflective roofing will help deflect excess heat.

Air vents to capture natural air flow will keep the roof cavity cooler by circulating air.

Utilising quality recycled Australian Steel is available.


Select lighting that lets in natural light (not the heat) and reduces electricity dependent lighting during the day. Use energy efficient light globes.

Natural Ventilation

Invest in natural ventilation so if there is a power-cut in the summer months, it will serve as a backup cooling plan to cope with the heat.

High Efficiency Lighting and Equipment

Choosing high-efficient lighting, office equipment and appliances will reduce the amount of waste-heat generation.

Heating and Cooling

Invest in cooling and heating solutions with a higher efficiency rating than is require today, because the projected increase in hotter summers and colder winters means what is chosen today may not be adequate in the future.

Landscaping to be Cool

Granny Flat LandscapingPlant large trees to provide maximum shade in the summer and use smaller trees, large shrubs and vines to minimalise searing heat on the exterior walls of the home. Channel cool breezes into the house during summer months by planting alleyways of plants, trees and shrubs; funnelling the natural air flow. Use local plants and plants that are drought tolerant.

Water Efficient Fixtures & Appliances

The most basic environmentally kind installations in eco-friendly granny flats are water efficient faucets, taps and appliances to conserve water.

Water Conserving Plumbing

A plumber (see utilities for granny flats) can identify the most efficient ways to conserve water in a new home. Talk to the manufacturer (list of granny flat builders) about options available, some of which may include – the diameter of pipes used, the distance the hot water cylinder is from faucets and appliances (as water is wasted waiting for hot water to come through, and expensive heated water sits in the pipes and goes cold when the hot tap is turned off), and rain water captured from the roof; to be stored and used for other purposes.

Designing a home to harvest rainfall is very sensible, especially if the home is remotely located in a dry area. Consider elevating the water tank, so in a power outage the water is gravity fed to taps and toilets when powered water pressure ceases. Install a rain water tank, anything over 1,000 litre is going to provide water for the garden, toilets or washing machine, thus minimising the water bill.

Eco-friendly granny flats should also consider using water restricted toilets, shower heads and taps with a minimum 4 star rating; 7 star rating is better.

Increasing Storms, Flooding & Rising Sea Levels

Severe storms are becoming more common and these storms potentially delivering more rain and causing flooding as they pass. When building a new home, build for possible torrential rain and prepare to endure possible flooding. Should the home be elevated more? Or, have storm-water trenches flanking the house to divert excess water away.

Building for Strong Winds

Building a granny flat to survive stormsStorms and cyclones are more common in areas of Australia so invest in impact-resistant windows, exterior window shutters and outwards opening doors (unlikely to be blown open in a severe storm). Buildings with a continuous-load path from the roof to the foundations are more likely to survive a severe storm (strapping with metal fasteners anchoring the roof to the walls and then to the footings). If doing DYI , ask a building engineer for advice to ensure a new home is more likely to cope with the lateral and sheer forces of a violent storm.

Avoid Flood Zones

Even when a property is not in a flood prone area or flood zone, check the area’s history and the predicted future of the area. Don’t rely entirely on local Council regulations (see Council approval for granny flats) because they can be slow amending them to reflect changes and may be out of date. Where possible, integrate new home storm management with natural water flow channels.

Raising a Home Off the Ground

Even in areas where flooding is not likely, raising a new home has advantages. Raising a Granny flat provides natural cooling during summer and protection from water damage if flooding does occur. Choose materials that can get wet and dry out without sustaining a lot of damage. For example: Choose tiles instead of carpet. The use of break-away walls around the footings or open vents will allow flood waters to pass under the home. This reduces pressure on the building’s structure inflicted when torrents of water are forced to go around the structure instead of through it.

Control Sewage

Install check valves in sewage lines for added insurance, as excess water from storms or flooding can choke pipes and push sewage back up the pipes into the new house. Install a grey water system.

Bush Fires

Building a granny flat in a bush fire prone areaMost homes burnt in bush fires are ignited by flying embers. Dry leaf-litter on the roof, gutters and troughs in complex roof lines is highly flammable as the roof is the most vulnerable part of the home. A plain roof line with no guttering is a better option. If gutters are essential, use leaf-gutter guards to keep dry flammable material from depositing in gutters. Hot embers can penetrate into the roof space through vents; especially in high winds. Investigate roof vents that can be shut off and made airtight should a bush fire be looming.

Windows break in extreme heat but double and triple glazed windows are less prone to smash; with tempered or reinforced windows being the most resistant to fire.

For more information about protect a home against bush, go to, where they list many useful tips.

Power Outages

Having a back-up generator, solar panels, wind turbines and hydropower all offer varying degrees of passive electricity in power outages.

Hot Water

Solar panels are a very eco-friendly source of cost effective hot water. Also, tank-less instant hot water systems are a very efficient water heating solution which produces hot water on demand, lowering the quarterly electricity bill.

In summary, any manufacturer (get a copy of the granny flats manufacturers directory here) will have the capacity to incorporate environmentally friendly building materials and use eco-friendly granny flats design principals during the Granny flat building process and provide competitive granny flat prices for a sustainable small home.

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