The world's first commercially available "smart" homes, which will be virtually self-sufficient in energy terms by using cutting-edge efficiency and microgeneration technologies, will be available by the end of 2009 for rent in Barcelona and Paris, developers told a conference in Spain yesterday.

The Smart Energy Home (SEH) consortium, a collaboration of university researchers, chemical and construction companies, hope that the homes will demonstrate the potential for cutting down personal energy use in the home, with plans for further homes in Warsaw and Berlin and ongoing discussions about a project in the UK.

Rudiger Iden of BASF, one of the companies in the consortium, outlined plans for the demonstration homes at the Euroscience Open Forum meeting in Barcelona. In Paris there will be an apartment block containing 200 dwellings, while in Barcelona, the SEH consortium will build around 40 flats.

On average, a family expends around 3,000 kilowatt-hours of energy per year and around 70% of that is used up in and around our homes. Iden said that SEH was aimed at reducing the environmental impact of this proportion virtually to zero.

Some of the technologies slated for use in the homes are tried and tested, such as using renewable energy sources to generate electricity - either wind turbines or solar PV panels and concentrators on the roof - and better thermal wall insulation. The SEH homes could also use smart energy-management systems that can, for example, use sensors to work out where there are people in a house and turn heating and lighting on and off depending on where it is needed.

Other ideas will be more advanced, such as the use of phase-change materials to even out fluctuations in temperature inside a building. These wax-like materials are embedded into the walls, storing heat when temperatures are high by melting. When external temperatures drop, the materials solidify and release the trapped heat back into the house. To even out seasonal changes in temperature, homes could collect excess energy during summer and use it to freeze a block of water in their basement. When the building next needs cooling, the water can be melted.

Next-generation energy-efficient appliances and organic LED lights will also be used in the SEH demonstration projects to cut primary energy use.

Iden said that previous attempts to use smart technologies in homes had foundered because of the way they had been designed so far - each technology in isolation from the others. "Innovative homes are currently substantially more expensive than standard houses due to low production volume of the products and lack of easy design solutions."

He also pointed to the lack of inspiring or visible examples of innovative homes across the world.

By contrast, the SEH consortium will design its homes as a whole unit. The first phase of their project will renovate older apartment blocks. "The lowest hanging fruit, the easiest money to be made is in existing buildings," said Laszlo Bax, director of the SEH project. "Of course, in a new build you can go further and have a better result in the end."

Eventually the consortium plans to build zero-emission homes from scratch and then "active houses" which can provide energy for themselves and sell excess into the public grid.

SEH was set up by an EU-funded project called SusChem aimed at introducing new sustainable technologies into building, will be formally launched in the coming weeks when the building contracts for the first apartment blocks are signed.

Bax said the consortium was set up to show that smart homes could be built using available technology and that people should be able to buy into the homes without having to choose between environmental sustainability and modern living. "The concept is not just sustainable from the point of view that's its good for the planet to have zero-emission homes but we'd also like to combine it with something that is seductive or persuasive for people who need to buy into such a home."

He added: "Trying to avoid having to make a choice of 'do I want to be sustainable or something that's nice for myself', we'd like the choice to be the same choice of choosing a smart energy home which is being good to the planet while being good to yourself."