Is it the plasma screens and halogen lights left glowing behind leaky Tudor windows? Or has the relentless trimming of lawns to within an inch of their lives put the residents of Thaxted at the top of the domestic carbon emissions charts? The commuter-belted swath of prosperous farms and historic villages that make up Uttlesford district council are best known as the homes of Jamie Oliver, Germaine Greer and Stansted airport. But the results of a study revealed yesterday show that its residents are the biggest domestic polluters in Britain.
The average household in leafy, tidy Uttlesford spews 8,092kg of carbon dioxide each year, more than double the comparatively clean, green dwellings of Camden in London, which on average produce just 3,255kg of CO2.
Two symbols of our energy crisis loom over the higgledy-piggledy, half-timbered houses of Thaxted.
The sails of the Essex town's stocky windmill stopped turning when it became uneconomic to grind flour with wind power in 1907. Overhead, more and more planes thunder overhead on their descent into Stansted.
Many residents are vocal campaigners against the airport's expansion. Most, however, seem unaware that their comfortable lifestyles, rather than the jets overhead, make them the biggest domestic polluters in the land.
Each year the average home here produces CO2 emissions equivalent to taking a Boeing 747 to Australia and back.
"There's all these huge pads out in the sticks where they leave their lights on all night and their big tellies on. That's where it's happening," said Joe Hobbs, an architect. Jake Roos, who has taken up the new post of the council's energy efficiency surveyor, agreed that affluence was the key problem.
"Uttlesford is a very affluent area and that has a knock-on effect in high carbon emissions. We try and lead by example but there is nothing else we can do to get people to save energy. It's not illegal to waste energy, unfortunately."
Domestic emissions make up 25% of the country's CO2 pollution. Keen to cut its share, the council is offering everyone two free energy efficient lightbulbs if they complete an energy-use survey about their home.
A grand total of none was collected yesterday from the office in Thaxted, although the council has handed out 5,000 - to nearly one in 10 homes in the area - since last August. Eileen Walsh, former chairman of Thaxted parish council, had another explanation for Uttlesford's unenviable record: farms - which require lots of energy to operate.
The area also has one of the lowest percentage of households connected to the gas network, which produces less CO2 than oil-fired, electric or open-fired central heating system. "I'm sure it's farming. It's also an affluent area and we like to heat our houses," said Mrs Walsh.
Some are already making strenuous efforts to tackle the problem.
Mr Hobbs lives in a new thatched house near Thaxted's old windmill, which is the energy-efficient exception to the rule. Planners rejected his first scheme for a grass roof but the one he built 18 months ago features traditional thatch, triple glazing with gas filling for thermal insulation and three solar panels to provide all his hot water. South facing, with state-of-the-art insulation, his home needs just one 4kw gas heater.
Mr Hobbs has also obtained permission to build a small wind generator in his garden; as it's adjacent to the historic windmill, the council could hardly refuse. But according to a local builder, Peter Wright, plenty of people have tried to fit solar panels and double-glazing but were refused on conservation grounds. There are 3,000 listed buildings in Uttlesford - nearly 10% of homes. Few can be fitted with panels or new windows; old homes are energy inefficient homes.
Affluent rural areas dominate the highest polluters in the report, which was commissioned by British Gas.
Second to Uttlesford is Teesdale, with an average of 7,731kg of CO2 per household, while Surrey Heath, Chiltern and South Oxfordshire are third, fourth and fifth highest polluters. The bottom five include three London boroughs - Camden, Westminster and Hackney - and Eastbourne and Norwich, both of which produce on average less than half of Uttlesford's emissions.
Ben Tuxworth, strategy director of Forum for the Future, said the study was a "wake-up call" to those who believed that reducing domestic emissions was a luxury for the wealthy. "Downward pressure on prices seems to mean that it's only the less affluent that bother to save energy. If the rich are using over three times as much energy as the poor, we need to incentivise them."
According to a Thaxted estate agent, Carl Fisher, even wealthy buyers do not want to spend on energy efficiency if they will not quickly recoup the cost.
"A lot of houses in the area have open fireplaces and they are well used," he said. "Residents are conservative - why spend money on anything that doesn't justify itself in the short term? There's an outdoor lifestyle here where people like to have their windows and backdoors open and probably have heating blasting out, costing them a fortune."