Berkeley’s barometer beacon highlights Tabard Square tower

The glowing beacon – officially unveiled on Thursday – changes colour depending on the barometric pressure. The glass box contains colour-changing LEDs which are controlled by a digital barometric pressure sensor.

• Very Low: Green
• Low: Green – Blue
• Low Mid: Cyan
• High Mid: Blue
• High: Purple
• Very High: Red

The main body of the beacon will be lit 24 hours a day, with the beacon at its brightest at sunset. To reduce light pollution, the light intensity will decrease throughout the night.

The barometric threshold values are based on inspection of measured annual weather data for the London area for each year since 1972, to ensure a sensible programme for colour change.

The colour transition from each threshold will take 60 seconds to complete. The beacon can also be set to display more dynamic colour shows for special occasions.

Opinion about the new beacon – which has been tested in recent days – has been divided. Some users of the London SE1 Forum have expressed concerns about the use of energy and the light pollution implications of the illumination. Other local residents have found the bright light intrusive.

"The beacon on the top of Tabard Square's residential tower is intended to act as a 'beacon for urban regeneration', and will enhance Tabard Square as a landmark and inspiration to the local community," says Mark Dickinson, MD of Berkeley Homes (East Thames). "We are sure that once people recognise which colour represents the variety of weather conditions, they will be able to use the beacon as an early warning weather system."

Tabard Square is one of the largest brownfield regeneration sites in central London at 1.2 hectares, and has transformed the former Pickfords Removals Depot on Long Lane into a mix of homes, shops, leisure facilities, commercial space – which includes the recently opened Bright Horizons childcare centre – and offices. The homes and commercial outlets will be set around a central public square.

Berkeley says that more than 80 per cent of the 572 apartments (£345,000 to £595,000) have already been sold.

• A major archaeological dig on the site found a 2,000-year-old Roman plaque and a pot containing a Roman cosmetic ointment.

How to read the Berkeley barometer

Pressure Range	Colour	Barometric air pressure ranges (millibars)
		Winter Dec Jan Feb	Spring Mar Apr May	Summer Jun Jul Aug	Autumn Sep Oct Nov
Very Low	Green	<999	<1004	>1009	<1004
Low	Green-Blue	999-1007	1004-1010	1009-1013	1004-1010
Low Mid	Cyan	1007-1015	1010-1016	1013-1017	1010-1016
High Mid	Blue	1015-1023	1016-1022	1017-1021	1016-1022
High	Purple	1023-1031	1022-1028	1021-1025	1022-1028
Very High	Red	>1031	>1028	>1025	>1028