Sometimes, half-measures seem more disappointing than out-and-out reversals. Take, for example, the reaction to recently released details of the British coalition government’s 2011budget for green measures in its “Plan for Growth,”whose relaxed home-building requirements have been called a “U-turn” by green-building advocates.

Under the government’s lowered standards, critics say, carbon emissions generated by homes built after 2016 would be reduced by only two-thirds of the amount required to bring them to true zero-carbon performance. That’s because the new government policy requires home builders to comply only with the UK’sBuilding Regulations, a national building code that covers carbon dioxide emissions from energy used for heating, fixed lighting, domestic hot water, and building services. Getting projects to full zero-carbon performance, however, would also require that they obtain their energy from carbon-neutral sources.

What’s really raised the ire of British green groups, however, is the government’s decision to exclude plug loads — electricity used for televisions, computers, hair dryers, and appliances — from consideration when making the zero-carbon determination.

A missed opportunity to lead on emissions reduction?

As noted in arecent post by green business website Greenwise, compliance with Building Regulations (most recently updated on October 1) is a crucial but incomplete step toward honoring the greenhouse-gas-emission mandates ofBritain’s Climate Change Act. Passed in November 2008, the Climate Change Act commits Britain to legally binding targets for greenhouse gas emissions, including a reduction in carbon dioxide emissions of at least 26% by 2020 (against a 1990 baseline) and a reduction by 80% of all greenhouse gas emissions by 2050.

So for green-building advocates, many of whom had worked on a consensus-based plan to define zero-carbon homes, the new budget policies are zero-carbon “lite” – or “anti-green,” as Paul King, chief executive of the UK Green Building Council, put it.

Last week, King complained that “in the space of two weeks, this government has gone from a firm commitment on zero-carbon homes to watered-down policy. A zero-carbon home will no longer do what it says on the tin. The world-leading commitment that new homes would not add to the carbon footprint of our housing stock from 2016 has been scrapped despite a remarkable consensus between industry and NGOs in support of it.”

Incentives for renewables

The government’s policy changes did include indications that the government will look for ways to advance the use of microgeneration technologies, however, by enhancing incentives for feed-in tariff programs and renewable-energy installations. The government says its Plan for Growth leadership will consult in May on the particulars.

The coalition’s deregulation approach alsoplayed well with the Home Builders Federation, a trade association serving England and Wales. “HBF welcomes the move to set a realistic objective that is within the gift of house builders to actually deliver,” said John Slaughter, the association’s director of external affairs. “It is critical that if we are to build the homes the country desperately needs we reduce the overall regulatory burden on house building sites.”

It’s too early to tell how much the government’s new policies will affect Britain’s ability to meet its Climate Change Act requirements, but the changes seems to have subverted the coalition’s promise to be the “greenest government ever,” says World Wide Fund for Nature-UK campaign manager Darren Shirley. “The government has undermined a unique example of the UK leading with a unique policy in Europe,” he said. “Zero-carbon new homes are now nothing of the sort.”