By Roger Harrabin
BBC Environment Correspondent
The UK government publishes its new climate strategy next week. Labour's stated aim is to cut CO2 emissions by 20% from 1990 levels in the next four years; and by 60% by 2050. Our correspondent Roger Harrabin considers how buildings fit into the climate policy mix.
Transport consistently grabs the headlines on climate change emissions but buildings pour out about half of the UK's CO2 - 30% from homes, 20% from commercial buildings.
The Chancellor said in his budget this week that he wanted the UK's homes and businesses to be the "most energy efficient in the world".
Although insulation standards are improving in new buildings (tighter Building Regulations will take effect next month) and appliances are getting more efficient, we are eroding those gains.
We are buying more gadgets, leaving them on stand-by, heating our homes to higher temperatures and building home extensions and conservatories that gobble more energy.
We are then inventing new gadgets like patio heaters, or high-definition TVs which use more energy than traditional models.
Our offices now have so many computers and other pieces of electrical equipment that they need constant cooling, sometimes throughout the year. Many offices are built to the cheapest price, so long-term energy use is not considered.
The result is that whilst CO2 emissions from buildings are supposed to be reducing, they are remaining virtually static.
One major problem is that offices are replaced at 2% a year and homes at 1% a year. This means most people live and work in buildings built to standards set before climate change was an issue.
Ministers are considering a plan by the Carbon Trust to impose tradeable CO2 emissions quotas on commercial firms and retailers.
This would make them look to cut energy use, which is often overlooked as it plays such a tiny part in their overall costs.
Home owners don't always make the most rational choices for improving energy standards either - they typically choose to install double glazing rather than cavity wall insulation, even though the latter saves more energy for less cost.
There are still many homes where people have not made a basic investment like draught-proofing and fitting heat-reflector shields behind radiators to make sure heat goes into the room not into an external wall.
The government expects a new subsidy initiative announced in Wednesday's budget will result in an additional 250,000 homes benefiting from insulation by 2008.
The government is also bringing in new incentives to encourage "smart metering" and a new labelling scheme which will indicate the energy efficiency of consumer goods.
The take-up of low-energy compact fluorescent bulbs has also been low - partly because some people don't like the light they produce but also because they cost more to buy than old-fashioned bulbs, even though they save cash in the long term.
What is more, customers buying energy-efficient goods or appliances face 17.5% VAT, whereas they pay just 5% VAT on burning extra fuel.
The government's Warm Front scheme puts £320m a year into insulating about 200,000 homes of people in fuel poverty.
The Energy Efficiency Commitment imposed on the power sector channels 1% of fuel bills into efficiency improvements. Half the total goes to the poorest homes; and the government is keen to push this project on.
The government is also backing a pilot programme in which local councils offer reduced council tax for energy-efficient homes.
But often the government has found its climate change policy in conflict with other priorities such as reducing the cost of homes, promoting competitiveness, avoiding red tape, being pro-business and avoiding damaging headlines.
Last year, the government watered down a previous proposal to impose much stricter standards on the building industry; but after a barrage of criticism, it appears ready to impose tougher rules again.
Government insiders say the minister responsible, David Miliband, is mindful of the political risks of inaction on climate change since the issue has been championed by the Tory leader, David Cameron.
One problem acknowledged by the government is the difficulty of enforcing building regulations. The Energy Saving Trust says a third of new homes do not meet current standards.
Ministers recently claimed their changes to building regulations would save 40% of CO2 emissions from new homes; but the figure has been challenged by the sustainable homes group, the Association for Environment Conscious Building.
It argues that the government's energy calculations are based on an outdated computer model that does not acknowledge people's desire to shower more often, use home entertainment and live in hotter homes.
The AECB estimates that the true CO2 saving from government building regulations is more like 10%.
The Royal Institute of British Architects (RIBA) applauds the government's good intentions on housing but complains that policies are too weak. Bill Gething, an advisor to the RIBA, says the government's new so-called sustainable communities are often traditional car-led developments that fail to meet the government's rhetoric.
The government denies these accusations. It says it is aspiring to improve standards - but has to work with the building industry, not against it.
The Building Research Establishment says if builders were forced to achieve the "excellent" grading on its rating system, it would put around 1% on the cost of the average home.
This would cut CO2 emissions by more than a quarter compared with "typical" new-build homes, and would save occupants around £138 a year in utility bills.
The UK is currently on track to meet its Kyoto commitment to reduce emissions of six different greenhouse gases by an average of 12.5% compared with 1990 levels over the years 2008 to 2012
The fall in emissions through the 1990s and early part of the 2000s was achieved at a time of strong growth in the UK economy
Carbon dioxide emissions have risen recently, largely due to increased burning of coal in power stations. This was prompted by a rise in the price of gas (gas is 'cleaner' than coal)
The Labour administration has stated in three election manifestos that it would like to see a 20% cut in CO2 emissions by 2010