New homes in Jersey will be at least 20% more energy efficient from 2011 as part of government plans to improve building and material standards.
New building by-laws will come into force in January with new energy targets set by planning and environment for homes and new buildings.
The new targets will also apply to existing properties that are extended or renovated.
At least 80% of lighting will need to be low energy in new buildings.
Jersey Electricity has already hosted a seminar to explain to architects and builders what the new by-laws will mean in practice.
It has been using the example of a development in Green Street, St Helier, where a 40-year-old building has become more energy efficient with a new heating and water system.
Richard Plaster, Jersey Electricity's commercial director, said home owners would not be responsible for changes.
He said: "It will be up to the trade, the developers, the architects and the like to design those improvements into the buildings so it won't be down to individual house owners.
"But the technology is there, we know how to do it, it is just a case of applying that technology."