The potential effect of external canopies in suddenly accelerating the spread of fire has been highlighted in research commissioned by Greater Manchester Fire and Rescue and carried out by BRE.

The research was carried out following an incident in 2008 at a house in Bolton where a woman died in an arson attack. The end of terrace dwelling involved was constructed of brick and traditional roof trussing with a composite tile covering. At the front of the house there was a timber canopy open on two sides with a felt roof, with front door and meter access area openings underneath it.

The fire had been started in a wheelie bin positioned next to the front door and underneath the canopy; adjoining the bin was a decommissioned fridge-freezer left our for collection by the local authority.

Firefighters were initially directed to the rear of the house where a number of rescues were carried out, and only light smoke was visible at the time. One firefighter was then directed to the front of the property where he saw a small fire under the canopy. The fire then dramatically changed to involve the staircase and landing areas to such an extent that firefighters were caught unaware of the rapidly changing circumstances.

The simulations performed by BRE show that the canopy and wall surfaces contained by the canopy had a profound effect. The canopy became a radiating panel, accelerating the temperature of the combustible materials below it until it was above their auto-ignition temperature and all available surfaces became simultaneously involved. It is estimated the fire grew by a factor of five in the space of two seconds.

In a memorandum to operational personnel, assistant county fire officer Tony Ciaramella said that while there were a number of circumstances that combined to the rapid development of the fire, the part played by the external canopy should not be overlooked. "There are a wide variety of similar structures in use made from a range of differing building materials; Incident Commanders and operational personnel should not overlook the possibility of unnatural fire development occurring in similar circumstances and this should be considered as part of the dynamic risk assessment process."

The report on the research is in draft form and is expected to be available before the new year.