The architect's historic search for a blueprint to keep light at bay

"Architecture", wrote Le Corbusier, the 20th century's greatest architect, "is the masterly, correct and magnificent play of masses brought together in light."

Today, architects spend an increasing amount of their time trying to keep light at bay. To be fair, the sun has always been both friend and foe, and architects since the earliest civilisations have been encouraged to mollify its intensity. In fact, it has only been relatively recently that they have allowed the sun to sear its way into every room.

For centuries, various designs and combinations of thick walls, deep eaves, shutters, brises-soleil, verandahs and arcades have been employed to keep us cool. No one knew about the link between the sun's rays and skin cancer until very recently, but no one wanted to be dazzled or frazzled by the midday sun. Except, of course, the English, who for decades have been resistant to any form of sunshading for buildings or streets.

Over the past decade, however, sunscreens have begun to appear on new offices (such as those at Stockley Park, the United States-style business park near Heathrow airport), schools and major public buildings such as the British Library. As well as keeping the sun at bay, both inside and around the edges of buildings, these also help to decrease the energy needed to cool them.

On the whole, we are safe from the sun indoors and only in danger out of doors. Even so, it is still rare in britain to see arcades, which allow us to walk in driving rain or scorching sun without being enclosed just as our predecessors did when out strolling along John Nash's original Regent Street in London or as lucky shoppers still do at the Pantiles in Tunbridge Wells, for example.

Techniques for keeping cool and safe from the sun are well known, tried, tested and as old as ancient Greece. It really is time to adopt them now and at precious little extra cost. Any overtly technological solution is in danger of using energy, generating heat and contributing to the problem of global warming. But there are ways to protect us and save on energy.

Some of the latest international stadiums, for example, feature deep canopies designed to keep the sun out of spectators' eyes at all times of the day while generating up to 40 per cent of the electricity needed to run them through solar panels.

The problem at the moment is not so much a lack of ideas or technologies, old and new, but the fact that there are no guidelines, much less legislation, to ensure that buildings help to keep us safe from the worst effects of the unmitigated sun.