Architecture: Not bathing but drowning in a sea of light: Bright night skies in our cities are bad for buildings and people, writes Carl Gardner

'IT WAS like something out of a Steven Spielberg movie, it was unbelievably bright.' This was the sinister effect, according to one local resident, of the green glow that lit up the night sky over Perivale in west London from Christmas until March. The glow was a by-product of a new lighting scheme for the historic Art Deco Hoover building on the Great West Road, recently converted into a supermarket by Tesco.

Residents in streets on either side, whose bedrooms were bathed in green overspill light, were not impressed and appealed to Tesco, Harry Greenaway MP and Ealing council. After three months the scheme was modified: floodlights on the worst-affected sides of the building were turned off, light levels reduced by 40 per cent and fittings along the roof parapet re-angled to cause less upwards spillage of light. The scheme is now turned off at 10pm.

Even in its modified form it is controversial, as evidenced by a rash of angry letters in the architectural press. Simon Bruxner-Randall of the design group Imagination, which was responsible for the scheme, justifies it on the grounds of appropriateness. 'Even in the Thirties, when it was built, the building was controversial and over-the-top. We felt the lighting had to be in the same spirit . . . and green is a predominant colour,' he says.

But many would say that exterior urban lighting can no longer remain a private whim; it raises too many questions of social amenity, public nuisance and energy conservation. The case of the Hoover building points up a glaring anomaly: while architecture is subject to extensive planning control, there is no regulatory framework for how owners or developers can light it. If someone wants to blast the front of their house with 5,000-watt searchlights, no one can stop them.

John Mason, president of the British Astronomical Association, says: 'If a company uses enormous energy resources to light a building, it is not just its business, but ours - there are real social effects.'

The BAA is greatly concerned about 'light pollution' above our main urban centres, and, increasingly, in previously unlit rural areas. Dr Mason explains: 'Light pollution is caused when artificial light is scattered by the atmosphere, producing the characteristic glow that blots out the night sky and makes it impossible to see the stars from most of our cities, even on cloudless evenings.'

Three years ago members of the BAA started the Campaign for Dark Skies - and rapidly won backing from environmental groups, lighting consultants and engineers, architects and town councils. Even David Maclean, Environment minister, has expressed support.

But still the problem gets worse. In the past 10 years there has been a massive increase in decorative floodlighting, security and road lighting - all of which have exacerbated sky glow. But the BAA does not believe that night-time lighting as such is to blame - most lighting design specialists agree that when well executed, lighting can enhance the urban environment and prevent crime.

The main contributors to light pollution, experts say, are poorly specified, outdated equipment and inadequate design principles. Decorative spherical globe lighting - the 'lollipops' much used in pedestrian precincts and car parks - are a case in point. 'Half the light goes upwards, they're totally wasteful,' Dr Mason says. 'Architects choose them because they look pretty during the day, but they are poor lights.'

With the rise of crime, there has also been a growth in area security lighting, often stuck on the side of buildings so that it dazzles passers-by throughout the night.

A classic example of bad security lighting can be seen on the Embankment, on the rear facade of the Ministry of Defence, facing the Thames. Motorists driving from Westminster towards Charing Cross are greeted by a row of dazzling floodlights, mounted at first-floor level, to light the gardens. Ironically, by creating high glare and heavy shadow behind objects, such lighting often provides good cover for criminals. Dr Mason believes that passive infra-red switching, which turns on lights only when someone approaches, and which has a strong component of surprise, is far more economic and effective.

Road lighting is also contentious. The Department of Transport is gradually replacing older-style road lamps with flat glass lanterns that direct all their light on to the road, rather than into the air. But do we need quite so much of it? And must it all be of the low-pressure sodium type (chosen for efficiency), which puts a depressing orange wash over everything? Most other European countries use the more aesthetically acceptable mercury lamps, which give a blue-white light and are only marginally less energy efficient.

The DoT also seems intent on extending roadway lighting well outside our urban centres. Recently, a proposal to light the section of the M3 which crosses Chobham Common was vigorously opposed by Surrey County Council on environmental grounds - an action with which Dr Mason concurs. 'Why is it needed? It's a straight road with no junctions - the DoT says it is doing it on safety grounds, but there's no research or statistics to back that up.'

One expert who has done as much as anybody to put good urban lighting on the agenda is Andre Tammes, the founding partner of Britain's largest specialist lighting consultancy, Lighting Design Partnership. For him, effective illumination, energy conservation and sensitivity to the architecture are intimately connected. During the past two years LDP has been heavily involved in devising lighting 'master plans' for towns and cities, starting with Edinburgh, Mr Tammes's home town, and including Londonderry, Leeds and St Andrews.

LDP's most recent - and possibly most sensitive - commission, from Westminster Council, is a reappraisal of the lighting in Trafalgar Square, in preparation for the millennium celebrations in seven years' time. It is curious that, far from being over-lit, a square often regarded as the centre of London vanishes away into a black hole at night: pedestrian lighting is feeble, Nelson's Column and the lions are hardly lit at all, while the surrounding buildings and roadways are illuminated by an incoherent mish-mash of intensities and colours.

Mr Tammes believes that if we are to crack the aesthetic and conservation problems involved in urban lighting, some sort of planning regulation, perhaps controlled by locally accountable lighting managers, is inevitable. In LDP's report on Edinburgh, now being implemented, it suggested some 'brightness control' limits for different areas of the city, to avoid competitive escalation. Westminster has laid out similar proposals in its non-statutory guidelines to be circulated to large building owners.

For Mr Tammes, the very concept of 'floodlighting' has done much of the damage. 'It encourages people to flood the front of their buildings with one blast of light, which washes out architectural details and leads to

considerable light spillage. LDP favours smaller, less obtrusive sources angled at buildings from different positions, which adds shade and enhances perspective.'

Mr Tammes also rails against unshielded, badly controlled lamps, which cause glare for building users and passers-by. Maximum respect for the architecture; minimum use of energy - these are the two rules that the best lighting design should adhere to.

In lighting as in architecture, Mr Tammes says, the dictum 'less is more' applies. 'In general we should only light the most important buildings, and then concentrate on their most interesting features, rather than the whole thing. And then don't use any wider, more powerful beam than is necessary to cover the area and provide contrast with its surroundings.'

Too many lighting schemes, he feels, fail to take account of 'relative brightness'. In unlit areas, 'a small amount of lighting can achieve a great deal.'

For examples of these principles at work, one need look no further than LDP's lighting schemes for the Langham Hotel on upper Regent Street, the Savoy on the Strand and, most recently, the superb scheme for the riverside facade of Terry Farrell's Embankment Place office block over Charing Cross Station. No matter what you think of Mr Farrell's design, there's no doubt that when seen from the South Bank after dark it becomes one of the city's night-time glories.

Carl Gardner is the co-author of 'Lighting Design: an Introductory Guide for Professionals', published on 29 April by the Design Council, pounds 45.

(Photographs omitted)