Shorter days, longer nights and the clocks going back all mark the onset of winter. But while most may prefer it lighter for longer, what degree of darkness do we really enjoy – and what chance do you have of living in a location that enjoys "true" night-time darkness and a sense of real remoteness?
The Campaign to Protect Rural England has, for several years, urged government action to limit light pollution from street lamps, overnight illumination of shopping centres, office blocks and public buildings, stark upward lighting from floodlit sports complexes and, at the household level, outdoor lights that are unnecessarily bright or disperse their illumination.
It has joined forces with the British Astronomical Association, asking over 2,200 people to stand outside their homes and count the number of stars they could see within the constellation of Orion. In 2007, 54 per cent could see fewer than 10 stars. Earlier this year, the CPRE and BAA repeated the experiment with the figure up to 59 per cent. Further research by the bodies has shown 83 per cent of Britons suffer at least marginal light pollution – and most suffer "substantial" levels.
The most common forms of pollution are "light trespass" when illumination from Britain's 22 million homes and 7.5 million street lights, even if designed with the intention of shining downwards, typically also extends upwards. Two other common forms are "sky glow" – that orange glow visible for tens of miles around towns and cities seen from the air or from distant roads – and "glare", the harsh white light on some modern housing estates and golf driving ranges at night.
"This is severe light pollution and it's increasing," Emma Marrington, of the CPRE, says. "We want to use this evidence to convince ministers and local councils to take action to tackle it, for example by ensuring the correct lighting is used only where and when it is needed."
If you believe such an issue has little or no bearing on the housing market, think again. Jayne Perks of Stacks Property Search & Acquisition, a buying agency, found a house for a client who would not move to a property if there was unacceptable light pollution. She says: "Finding the perfect house was a challenge. The deal nearly came unstuck when we realised the night-time outlook was spoiled by light pollution from a nearby garage. Its lights remained on throughout the night. Fortunately, they were understanding and agreed to turn their lights off when the garage closes for the day."
Even in classic countryside light pollution can deter particular buyers. "Some houses in what might ordinarily be considered rural locations can be affected by lights from farm buildings. Dairy farms start at very anti-social times and have big illuminations" says Robin Gould of Prime Purchase, another buying agency.
"It's amazing how these have had an effect on the countryside – the other day when driving over a hill it struck me that the vale below had a lot more lights evident than I remember from just a few years ago. On the positive side, some town councils are switching off street lights late at night to save money," says Gould.
Those locations with the "purest" night-time darkness, according to the CPRE's dark sky maps, are Dartmoor, Exmoor and the Quantock Hills in the South West; Salisbury Plain and the top of the Chilterns in Southern England: parts of Lincolnshire to the east; the Black Mountains and the Brecons in Wales; the Yorkshire moors and some of Northumberland; plus large swathes of Scotland, outside major cities and the Borders. However, those areas were all (perhaps by definition) among the least populated in the country.
The estate agent selling Slattenslade Cottage, a house at Parracombe on the Exmoor coastline at north Devon, makes a point of mentioning the "true" darkness of the area in the property details. "The absence of light pollution can be a selling point, particularly for a London-based buyer seeking complete serenity," explains Stephen Richards of Chesterton Humberts (selling the property for £675,000 at chestertonhumberts.com).
Another dark property is on sale close to Galloway Forest. Craeganfois is a six-bedroom stone house with views to the Galloway Hills and almost perfect darkness at night. (£465,000, Strutt and Parker, 0131 718 4488, struttandparker.com).
Early this year Sark – at just two square miles, the smallest of the four Channel Islands – became the world's first officially-designated "Dark Sky Island". The US-based International Dark-Sky Association measured Sark's night-time illumination levels and assessed the degree of visibility of constellations in the night sky; to assist Sark's claim, one of its government officers visited every outside light on the island and recommended measures to cut artificial light "seeping" into the sky.
Sark is not Britain's only dark success. In 2009 Galloway Forest in Scotland was designated Europe's first "Dark Sky Park"; the local tourist board and local authorities say visitor numbers are booming, a new observatory is planned for the edge of the forest, and neighbouring local councils have introduced restrictions on outside lighting to preserve the quality of darkness.
These locations, however, remain the exceptions to the light-polluted rule. Those exceptions are getting rarer thanks to what the Campaign for Dark Skies calls a "wasteful" over-provision of domestic lighting by British householders. To illustrate its argument, it points out that security lights in British homes are typically 150W in strength – and that the Smalls Lighthouse, west of St David's in Pembrokeshire, uses only a single 35W bulb which is visible 21 miles away.
* Lydford, on the western fringe of Dartmoor in Devon, has buildings dating back to the 12th-century and tries to maintain its traditional image – and that includes having no street lights or household security lights, despite having a popular tourist cycle route and 400 residents in the village.
* Coll, an island in the Inner Hebrides, is 13 miles long and three miles wide with two main roads and a small airport, yet has no security lights on homes, or traffic or street lights.
* The Rutland village of Market Overton has reduced its light pollution by replacing its old sodium street lights with modern light-emitting diode lamps. Its 39 lamps cost over £20,000 in total to convert – but immediately produced an 80 per cent saving in electricity.
* Britain's 7.5 million street lamps cost an estimated £500m a year to run. Each one costs between £20 and £40 annually; about 80 per cent are now reported to be dipped or turned off for part of each night as local authorities seek to cut spending.
The right light
* Environmental Protection UK (environmental-protection.org.uk) says householders should ask themselves these questions before fitting outside lights:
* Is lighting necessary? Could safety or security be achieved by screening or locking away items?
* Do lights have to be on all night?
* If lighting is necessary, is it the optimum level? For domestic security a 150W lamp is adequate while the common high power 300W and 500W lamps create too much glare, potentially reducing security as it can temporarily "blind" an eyewitness. A 9W porch lamp is adequate in many cases.
* Are lights for safe passage correctly adjusted to illuminate only the surface intended and not neighbouring properties or even the sky?
* Are motion-triggered security lights correctly adjusted to only pick up movement in the area intended? To reduce glare, main beam angles should be below 70 degrees.
* Is light usually directed downwards? This minimises light pollution but if uplighting has to be used, install shields above the lamp to reduce wasted upward light, and try to avoid any equipment that spreads light above the horizontal.Reuse content