THE Greens yesterday unveiled their first major initiative in Government -- but it will cost buyers of new homes next year an extra €15,000.
Under a new energy plan, all new houses and apartments built from next July, will have to use solar panels or wood pellet stoves.
It is part of a drive to cut carbon dioxide levels by 40pc.
The measure represents the party's first major impact on government policy.
But last night it ran into serious difficulty with builders and opposition politicians.
The regulations will pose a major headache for the building industry. Tens of thousands of homes, which will now be governed by the new measures, have already been granted planning permission. That means architects may have to revisit plans to make sure they meet the new requirements.
Green Party leader John Gormley insisted the moves were "good for the environment and good for the consumer" and that there was "broad agreement" across the construction sector for the initiative.
Construction chiefs, however, warned that they could not possibly meet the new requirements within the timeframe laid down by the Government.
A spokesman for Construction Industry Federation (CIF) chief Tom Parlon -- a former PD junior minister -- told the Irish Independent: "We don't have the technical capacity to do this."
The Greens also came under political fire over the costly new measures.
Fine Gael accused the smaller government party of hypocrisy, saying the new regulations came just one week after the party opted to cut the Greener Homes scheme.
"Instead of slashing grants to existing householders who wish to reduce energy usage, funding should have been increased," Fine Gael's new party environment spokesman Phil Hogan said.
It is estimated the new energy-efficient measures will add an average of €15,000 to the price of new homes from next July. However, the Greens claim houses and apartments will be cheaper to run.
The regulations announced at the Green Party think-in in Co Wicklow yesterday provide for a radical improvement in energy-efficiency standards.
They include a minimum renewable energy requirement in all new homes; while solar heating systems or biomass systems, such as wood pellet, will have to be used.
A certain amount of lighting in the home will have to be energy efficient, while 'greener' and more efficient heating systems must also be installed.
Houses will be tested for 'air tightness' to ensure they are not leaking heat excessively. New buildings will also be 'future-proofed' to allow them to be upgraded to higher energy and CO2 standards.
Mr Gormley praised officials for fast-tracking the new regulations, despite the industry's belief it would not be able to adapt so quickly.
"The draft regulations which I have published today will change forever the way we deal with the housing stock under the building code," he said.
"These regulations are the first step in the process of achieving carbon zero housing.
"The benefitin savings on energy costs, as we face into an uncertain future with regard to carbon-based fuel costs, will be a benefit to homeowners.
"It will also make a significant contribution to Ireland's efforts to reduce greenhouse gas levels."
Natural Resources Minister Eamon Ryan added that more than 6,000 houses with a 40pc improvement in energy efficiency had been constructed under the Houses of Tomorrow scheme.
"This shows the demand that exists and how regulation is the next logical step," he added.
The measures apply to all planning permissions granted for housing after July 1. But all homes which have not been "substantially completed" by July 2009 will have to include the new measures.