The buildings section of our SkyriseCities Forum includes four groupings of structures based on height. Those four groupings are: Lowrise, Highrise, Skyrise (Skyscrapers) and Supertalls. In today's Explainer, we describe the differences between these four classifications.

On SkyriseCities, the definition of lowrise is any building 99 metres in height or shorter. Some other sources have alternate definitions, such as Emporis, which describes a lowrise as a building with a height below 35 metres. The SkyriseCities classification also includes midrises, which the City of Toronto considers any building between four and 12 storeys tall. 

Toronto's Picasso Condos is a highrise building, image by Marcus Mitanis

The exact meaning of highrise similarly wavers from source to source, but the sheer amount of projects worldwide has necessitated a 100-metre starting point on our Forum. Skyrise generally refers to skyscrapers of a height greater than 200 metres. 

The definition of supertall is more firm. As most countries use the metric system, any building above 300 metres in height is deemed a supertall by the Council on Tall Buildings and Urban Habitat. The United States, which uses the imperial system, often sticks to a 1,000-foot — or 304.8-metre — marker for simplicity. The term 'megatall' has also been gaining popularity and refers to buildings over 600 metres in height. Currently, only a few structures meet that criteria. 

The Burj Khalifa, a supertall, is the tallest building in the world, image by benmfulton via the SkyriseCities Flickr Pool

Do you think the definitions that classify buildings will change over time as new heights are reached? Let us know by leaving a comment in the field below.