A new report shows rising material levels are driving a rise in the height of buildings.
The study by the National University of Singapore, which looked at building height data for the period between 2000 and 2015, found a rise of more than a metre in height over the same period.
“In the case of tall buildings, there is evidence that there has been an increase in the rise of material (machinery) heights,” it said.
The rise in building heights was greatest in Melbourne, which recorded a rise by 7.8m (22.5ft) in height between 2000-15.
The number of buildings with higher heights than the average in the state grew from 9,723 to 14,869.
The findings are likely to add fuel to an ongoing debate about the potential for building height to be affected by the rise in carbon emissions.
Building heights have been set at 5m (16ft) since the 1970s, with the height threshold set at 6m (18ft) at the height limit of existing buildings.
In Melbourne, the limit was set at a maximum of 8m (25ft) to encourage people to build taller.
But in a number of other cities, the building height limit has been set too low, with some building heights above that limit, such as in Sydney, Sydney Central and Penrith.
“The building height thresholds are too low,” said the report’s co-author, Dr Paul Chan.
“We’re not saying they shouldn’t be set higher but they shouldn [be] set higher, which is why we’re concerned that the building heights are going up.”
Dr Chan said the rise was likely to be caused by a rise to materials used in buildings, which increased the building’s structural strength.
“This is a phenomenon we see in all of our construction materials, from reinforced concrete to steel, we have a tendency to use more of it,” he said.
“These are materials that are extremely strong and durable.”
Dr Sami Ali, from the University of Queensland, said the study was important because it showed a trend of rising building heights over the past 15 years, particularly in Melbourne.
“I think it’s interesting to see a rise from 2000 to 2015,” he told ABC Radio Melbourne.
“In Melbourne the building boom of the past 10 years is largely because of the rise to the building material height thresholds.”
It suggests the building industry needs to focus on using materials that can withstand high levels of heat and pressure and be able to withstand the stresses of a building, rather than just building for a short time.
“Building height is measured by how much the structure can rise above ground level, as measured by height above ground.
Mr Ali said a rise that big could cause serious structural damage to buildings, especially in buildings that were not designed to withstand such conditions.”
There are a lot of buildings in Australia that are quite vulnerable to a large building rise,” he added.”
People are building these high-rise buildings because they have no choice, they can’t afford to live on a smaller building or they can only afford a smaller house.
“But you don’t want to get the wrong message from this study: that building heights should be set at these higher heights, because they are going to be very, very high.”
Dr Ali said the new study’s findings showed that building height was not an inevitable consequence of rising carbon emissions from increased CO2 emissions.
“Building height was a result of a lot more than just climate change,” he noted.
“When we have increased carbon emissions, it has been driven by other factors.”
What this study shows is that building building heights in Australia are not an absolute function of carbon emissions because the building of buildings is also a function of other things.
“Dr David Withers, from NUS’s Centre for Environmental Science and Policy, said there was a “huge range” of factors that could have contributed to the rise.”
So far, we’ve seen an increase of around 10% in building height over a 20-year period,” he explained.”
Some of that is the result of buildings being constructed to meet emissions targets.
Some of that can be attributed to building intensification and the use of materials with a lower melting point and so on.
“Others are simply related to population growth, because it is more urbanised.”
A lot of it can be related to changes in the way we live and work, and that has also increased the volume of building material and the number of people who are building structures.
“Dr Wither-Sears said the increase in building tallness was also a result, at least in part, of changes to the land.”
Land use is becoming more complex and people are choosing to build buildings closer together,” he suggested.”
If we look at the building site as a whole, we’re finding that we’ve had a lot fewer building sites close together, and we’ve also had more development on land.
“The report found