Four fire engines and around 20 firefighters were called to the site at the junction of York Way and Crinan Street, King's Cross, central London at 8.36 am this morning (26.06.06).
A spokeswoman for the fire service said: 'Half of the eighth floor of the building is alight. An acetylene cylinder is involved in the fire and a 200m exclusion zone has been set up as a precaution, as some cylinders can explode when exposed to heat.
'One person has been taken to hospital suffering from burns.'
Dixon Jones learned about the blaze from the AJ. Partner Edward Jones said: 'One of the cores is on fire. Fire engines are all over the place.'
Work on the eight-storey King's Place mixed-use project, led by Sir Robert McAlpine and developer Parabola Land, began last June.
When it opens in 2008, Kings Place will include 26,000m 2of office space, together with a 425-seat concert hall, art gallery, restaurants and retail spaces.
The design features a distinctive curved wave wrapping around to the Crinan Street elevation and a set-back upper storey.
The building will bring together Guardian Newspapers' 1,400 London staff - currently scattered across seven London sites - and provide a new home for the London Sinfonietta orchestra.
It is unclear to what extent the blaze will disrupt the construction schedule.