The unfortunate incident of building collapse at 11, Oba Idowu Oniru Road, Oniru Estate, Victoria Island, Lagos on Sunday, 4 September, 2022 has again exposed the inaccuracy and lack of understanding in the use of the terminology, ‘STOREY’ in this part of the world. The collapsed building was referred to severally in the media as a seven- storey building, while in fact it was a nine- storey building.
This wrong description is a misnomer that has grave implications. The photograph here, which is that of the building before it collapsed, revealed that it had a ground floor, seven suspended slabs/floors and a penthouse floor making a total of nine storeys. As observed in the photograph and video clips of the building while it was still standing, the nineth storey, which was on top of the building was a penthouse.
The importance of appropriate determination of the height of a collapsed building cannot be overemphasised. In the post mortem analysis or investigation, knowing the actual number of storeys would show if the building exceeded or complied with the approved building plan or the height restrictions in the model city plan of that area (density regulation). Moreover, the number of storeys is a critical variable in the structural calculation and analysis of loadings exerted on the foundation of the collapsed building.
There is a significant difference in the sizes, types and details of the foundations expected to carry a seven-storey building and those of nine-storey buildings, with varying degrees of soil bearing capacity.
In building lexicology, the meaning and use of storey is constant and the same across the world. However, conflict exists in the Britannica and American use of ‘FLOOR’ in the counting of a building height. Ground floor in Britain means first floor in America.
The need to correct the constant wrong use of ‘storey’ in Nigeria is very important.
The meaning of storey is the same all over the world. Storey is defined as the floor or level in a building, including rooms on that floor. This means that a storey extends from the floor to the ceiling or suspended slab. It is used for horizontal division of buildings. Hence, a bungalow which usually is a house that has only ground floor is a one-storey building. A building that has a ground floor and an upper floor is a two-storey building.
The etymology of storey traces the early use of the word to the period from 1175 to 1225 in Europe when artistic display of events on stained glass windows and walls of different floors were used to promote history. Hence, storey originated from the Latin word, historia, which reflected in the Anglo-French word estorie.
There is no ambiguity in the global use of storey. Ambiguity only exists in the counting or numbering of floors in different parts of the world. There are two major floor numbering methods in the world: The English or European method that counts ground floor as zero and the American method that prefers to label the ground floor as the first level. In that case, first floor in European method means second floor (level) in American method. Most countries in Asia, Latin America and Africa adopt either of these two methods of floor numbering.
However, the difference in the two systems is unified in the use of storey. A building with ground, first and second floors in European system is a three-storey building. The building numbered first, second and third floors in the American system also remains a three-storey building. A subterranean room, a cellar or basement is a storey below the ground floor in European method or a storey below the first floor in the American method.
It is therefore important to overcome this Nigerian error, the distortion of storey that has long been confusing even the Nigerian construction practitioners. Dictionaries and building control regulations have a consensus on this. The use of “storey” will serve as a more concise and appropriate word to distinguish different heights of buildings for effective communication of building height specifications.
May the souls of those who perished in the avoidable collapsed nine-storey building rest in peace.
Mrs Okusaga, FNIQS, is Chairman, Lagos State chapter of Building Collapse Prevention Guild
