I read your column every weekend and today the article on fall risks for children caught my eye! For the past two years I've been part of a working party established by The Children's Hospital at Westmead to investigate the increasing incidence of children falling from residential buildings (houses and apartments) and to develop solutions to address the problem. In February this year we released our 'Outcomes Report'.
Movable planter boxes are a problem. They are not covered by the building codes because they don't form part of the building. This aspect is a matter of safety awareness and education which has been addressed in detail in our report.
Fixed planter boxes and balustrade heights/designs on new buildings are covered and required to incorporate child safety features such as not having elements that could be climbed.
Your comment that by 2030 half the population will reside in multi-unit housing is concerning in terms of child fall risks as many families will form a significant proportion of the population living in this type of housing. There are 16 recommendations in our Outcomes Report and two recommend changes to the Strata Schemes Management Act and the Residential Tenancies Act to require owners/landlords to fit locks or window opening limiting devices to enable occupants (parents and carers) to restrict the opening of windows to 100mm. This is particularly important in children's bedrooms where a significant number of falls occur.
Draft proposed amendments to the the Building Code of Australia (currently on public exhibition) will require some design changes to windows and balustrades to deal with child fall risks however the changes fall short in terms of windows being required to be fitted with limiting devices as standard features.