The workers injured in the Clapham housing collapse were lucky - two thirds of construction deaths occur on small sites

Last week’s housing collapse in Clapham was a pertinent reminder of the importance of the HSE’s planned blitz on refurbishment sites. This particular near disaster, where three workers were injured, is just the type of site that the HSE should be targeting.

It’s own figures show that one out of three refurbishment sites pose a danger to workers, and 67% of deaths occur on small sites. This site is typical of the subject of these figures.

While it is hard to prejudge the outcome of the HSE’s investigation into the causes of the collapse it is probably safe to say it is unlikely to have fallen down by itself.

The pictures show a Victorian rear addition which is part of the new high property price stamp duty fuelled trend – adding a basement underneath your home has become cheaper than moving to a bigger house for some people.

Given that domestic buildings of this age usually have foundations about 18 inches deep adding a basement is a structurally challenging proposition that should only be carried out by specialists experienced in this type of construction.

The walls have to be carefully underpinned in small sections and likewise the earth has to be dug out in sections too. In this particular case the basement appears to extend beyond the rear wall into the garden, necessitating the insertion of a steel beam to support it. The chances are something went wrong during the basement addition.

While this collapse may be an extreme case – adding basements is still comparatively rare compared to say, loft conversions – the general standards of health and safety on smaller sites can be appalling (just see our Safety Blunders).

While the HSE blitz is overdue the real challenge is getting the health and safety message across to people on the small sites.