By Victoria Bone
The BedZED project in Surrey is an example of an eco-community
Gordon Brown wants to build five new "eco-towns" with 100,000 environmentally friendly homes.
Households are responsible for about 27% of the UK's carbon emissions and almost a third of the nation's total energy consumption.
So what exactly is an eco-home? And what can you do to make your home more green?
Mr Brown wants to build 100,000 eco-homes on former industrial - or brownfield - sites to avoid swallowing up countryside or green belt land.
An ex-MoD base at Oakington in Cambridgeshire - an asylum seeker holding centre - is already earmarked with councils invited to bid to host the other settlements.
Once a site is chosen, orientation is also important.
Building south-facing homes maximises so-called "passive solar gain", using the sun to heat rooms wherever possible.
Spaces prone to over-heating, like offices, can be built with a north-facing aspect to reduce the need for air conditioning.
Eco-homes are not a new idea and there are many already across the UK.
One example is BedZED - the Beddington Zero Energy Development - completed in 2002.
There, homes and offices were built on reclaimed land owned by the Sutton Council in south London and sold to the developers, the Peabody Trust, at below market value to support the planned environmental initiatives.
Wherever possible, eco-homes are built using natural, recycled or reclaimed materials.
Any wood should be from a sustainable source and approved by the Forest Stewardship Council or similar organisation.
Sue Riddlestone, executive director of sustainability solutions company BioRegional, which consulted on BedZED, says materials should have a low "embodied energy", meaning the amount of energy required to manufacture them.
"Materials should be sourced as locally as possible to cut the energy used to transport them to the site," she adds.
BedZED's buildings are constructed from "thermally massive materials" which store heat during warm conditions and release it at cooler times.
Energy for eco-homes should come from renewable sources, and wherever possible be generated on the buildings themselves or the site.
BedZED is powered by a small-scale combined heat and power plant (CHP), fed by off-cuts of wood from tree surgery which would otherwise go to landfill.
Traditionally, heat produced as a by-product of electricity generation is lost, but CHP harnesses it and puts it to use.
At BedZED, it provides hot water, distributed around the site via super-insulated pipes. In individual homes, there is also a hot water tank which doubles as a radiator.
This is a community-scale solution, but individual houses can also make a difference.
Like Conservative leader David Cameron, you could have a wind turbine installed. It costs from £1,500, but grants may be available.
Solar panels, costing from £2,000, can also be fitted on the roof of an eco-home and can provide 100% of heating and hot water needs in summer.
Photovoltaic cells, at £4,000 or more per home, also use the sun's energy to generate electricity.
Eco-friendly energy could even come from the earth itself, using a ground source heat pump to warm water and contribute to central heating. This costs from about £6,400.
But if all this sounds expensive and difficult, even simple fixes make a difference - double glazing, for example, halves heat lost through windows.
Loft and cavity wall insulation too, can cut heat loss from walls and roofs by a third, according to the Energy Saving Trust (EST).
Even just turning the thermostat down by one degree can cut heating bills by 10%.
LIGHTING AND APPLIANCES
Low energy lighting and energy efficient applicances are key to cutting back on household carbon emissions.
Environmental groups say that although these do cost more initially, that expense is more than repaid longer term by the amount of energy saved.
Samantha Heath, director of the London Sustainability Exchange, says: "A fridge is one of the greediest appliances, so make sure it's as efficient as possible. And avoid plasma screen televisions, which just eat electricity.
"We should also be thinking about using appliances like dishwashers and washing machines one at a time to avoid an energy overload."
She adds: "One of the most helpful new gizmos is a device which turns everything off but the one appliance currently in use."
The Energy Saving Trust says the average household has up to 12 gadgets left on stand-by or charging at any one time, and more than £740m of electricity is being wasted this way.
So turn off your TV, unplug your mobile charger and switch off lights when you leave a room.
Also, try washing clothes at 30C instead of 40C - it uses 40% less energy.
WATER AND WASTE
"Water is a big issue, especially in the south of England," Ms Riddlestone says.
"At BedZED we have cut water use by half by using more efficient appliances like washing machines and using rain water to flush toilets."
Again, if you cannot stretch to those fixes, you could buy a water butt to collect rainwater to use on your garden.
Ensuring no water is wasted goes hand in hand with recycling of all kinds.
"An eco-community can recycle up to 65% of its waste," Ms Riddlestone says. "And what's left shouldn't go to landfill - you can find other ways to recover energy from that as well."
"It's not just about building houses. The approach we take is to look at the whole community and how people live in it," Ms Riddlestone says.
"It's no good saving energy in the home if you then get in the car every time you need to go shopping."
So, an eco-home has to fit into an eco-community.
Mr Brown said eco-towns would have bus routes and cycle lanes designed in a way to make them carbon neutral communities overall.
At BedZED, a car pool has been set up for residents and a 'pedestrian first' policy in the design means there is good lighting, drop kerbs for prams and wheelchairs and a road layout that keeps vehicles to walking speed.
There are also local shops and a nursery, and good public transport links to enhance quality of life and cut car use.