The three-storey buildings were reduced to rubble in January 2011 and neighbouring properties sustained serious structural damage.
Westminster Magistrates’ Court heard that Ethos Construction, led by director Pritish Lad, was the principal contractor for a major project to refurbish a self-contained block of 14 buildings on Fulham Road to create 56 new apartments and 13 commercial units.
Adjoining properties at numbers 270 and 280 collapsed without warning on Sunday 23 January.
The weekend timing meant there was no work activity and nobody was on site.
The fallen rubble and debris took several days to clear and Fulham Road was partially closed for several weeks while neighbouring buildings were checked and made safe.
A Prohibition Notice was put in place to stop the resumption of the renovation project until the site was declared as safe and stable.
HSE inspectors identified a number of safety failings in investigating the collapse. They included:
• Allowing existing structures to become weak and unstable. There was evidence of renovation activity within the collapsed buildings, including work on party walls and the demolition of rear extensions.
• Not assessing whether there was any evidence of a collapse risk.
• No temporary works plan for workers and no checks on whether workers were sufficiently trained and competent to undertake the work
• The storage of large piles of bricks on several floors of still-standing buildings, which posed a potential over-loading risk.
• The poor installation and positioning of building props.
HSE also identified further issues elsewhere, including: an unsafe excavation up to three metres deep running the entire length of the development site; risks concerning working at height; fire risks because flammable materials were poorly stored and controlled; a failure to provide suitable emergency exits; insufficient fire detection and fire fighting equipment; and inadequate site security.
Two further Prohibition Notices were served to immediately stop unsafe activity.
Ethos Construction Solutions Limited, of Chesham, Bucks, was fined a total of £14,000 and ordered to pay a further £9,000 in costs after pleading guilty to safety breaches.
Pritish Lad, 34, of Hatch End, Pinner, Middlesex, pleaded guilty to safety breaches and was fined a total of £9,500 with costs of £6,750.
After sentencing HSE Inspector Andrew Verrall-Withers commented: “The development site was a scene of complete devastation following the collapse and had anyone been working at the time there could have been multiple fatalities and serious injuries.
“It is also good fortune that the collapsed building didn’t come down in the direction of the busy Fulham Road, which could also have had tragic consequences.
“Thankfully that wasn’t the case, but they are the only positive outcomes from the incident.
“The failings we identified at the site were shocking, both in terms of their scale and severity, and there were numerous risks elsewhere that could also have caused death or injury.”