Complex sentence: Two of the buildings had been constructed before fire escapes had been a mandatory building requirement and the Fire Brigade had not required them to be installed later, despite having a bylaw since 1930 where they could have directed the building owners to install fire escapes.
Split into simpler sentences: Two of the buildings had been constructed before fire escapes had been a mandatory building requirement and the Fire Brigade had not required any to be installed later. This happened despite a bylaw since 1930 where they could have directed the building owners to install fire escapes.