RR1219: A study of the effectiveness of guarding to prevent falls through window openings
To protect against the risk of persons falling through window openings in buildings, The Building Regulations 2010 (England) Approved Document O (ADO) – Overheating (2021 edition) sets a guarding height minimum standard of 1100 mm for windows in upper floor dwellings which can be opened as part of the overheating avoidance strategy for the building.
The research team sourced and reviewed peer-reviewed scientific primary papers, standards, building regulations, and guidance documents published between 1990 and December 2023 for insights about heights of barriers and prevention of falls through windows. Fall risk was further characterised through anthropometric and biomechanical analysis of the ability of 800 mm and 1100 mm high guarding to protect against falls over them.
There was no empirical or epidemiological evidence in the literature comparing fall incidents at different heights of guarding; research has so far only compared an absence of guarding with its presence.
The study found no evidence supporting the case for having different guarding heights for different storeys of a building on the basis of risk.
There was also no evidence to enable an assessment of the impact of dynamic actions on fall risk in relation to the two guarding heights. However, active play and climbing behaviours are generally reported to increase risk of children falling from windows.
The risk of a person tipping over guarding intended to prevent a fall is increased if the person’s centre of mass (COM) position is above the guarding.
A guarding height of 1100 mm is protective against tipping risks for practically the entire adult British population, whereas a guarding height of 800 mm is protective for less than 1% of the adult population.
Visit the RR1219 report (PDF) [12]
This report and the work it describes were funded by the Health and Safety Executive. Its contents, including any opinions and/or conclusions expressed, are those of the authors alone and do not necessarily reflect HSE policy.
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