In many of the world’s major cities, the only way is up. Over half of the global population live in cities and urban areas. Within the next 25 years, another 2.5 billion are expected to join them. In increasingly densely-populated cities, vacant plots are hard to find. Hence the rise of the high-rise.
There’s also an element of architectural vanity involved in building skyscrapers. Building materials, fashion aesthetics and technology have progressed to build the architecturally stunning offices of the future, but this has come with a cost.
Convenient as high-rise buildings are to accommodate the occupants of growing cities and delight our aesthetics, these buildings have been proven to be high-energy consumers. According to a new study by the Energy Institute, University College London (UCL), the taller an office and residential building, the more energy per square metre of floor area it will use. In fact, electricity use per square metre of floor area is nearly two and a half times greater in high-rise office buildings of 20 or more storeys than in low-rise buildings of six storeys or fewer. Gas consumption also increases with height by around 40%. As a result, total carbon emissions from gas and electricity from high-rise buildings are twice as high as in low-rise.
China, which is home to some of the world’s tallest towers, has sat up and taken note. The country is limiting the construction of super skyscrapers to help reduce its energy consumption. The Chinese government explained that massive skyscrapers are impractical in low-density cities, ruling that:
• Skyscrapers taller than 150 metres will be strictly limited
• Buildings higher than 250 metres will be banned in areas with a population of less than 3 million
• Structures taller than 250 metres will be limited in cities with over 3 million people
A rising issue
Nowadays, it’s perfectly normal to see beautiful glass-windowed office buildings in city centres, but these entire glass structures come with energy risks. Entire glass structures allow more sunlight and heat in, which means that these buildings need more air conditioning units. Not only do they let hot sunlight in, but large windows also leak heat in cold weather. Carbon emissions from these air-conditioned offices are 60% higher than those with natural ventilation, the UCL study revealed.
And the prevalence of air-conditioning is rising worldwide. It is predicted that energy consumption for air-conditioning could triple by 2050. Even if energy is sourced from renewable sources, it would be a challenge to meet this demand.
Smart solutions for skyscrapers
Slowly, we have seen some of these iconic buildings transform into green structures for the future by using smart technology. The rapid emergence of machine learning (ML), artificial (AI) intelligence and big data provides opportunities for property developers to reduce inefficiencies, energy consumption and carbon emissions.
Smart meters, automated meter readers, and various sensors around buildings are collecting more and more data. Building control systems can then harness this data through the use of AI, ML and automation.
One example of a system that promotes energy efficiency in a building is a smart energy management system, which collates, reports on and analyses real-time energy consumption and historic patterns using data from smart meters. Having access to this data allows building managers, governments and consumers to:
• Facilitate behaviour change that reduces energy demand
• Facilitate innovation
• Inform government policy
Combined with geospatial data, smart energy data can be used to help local governments gain a detailed understanding of the energy performance of buildings at a city, regional or even national scale. As a result, they will be better equipped to plan more efficient and effective renewable energy supply and heat transfer technologies.
In the building itself, the benefits of smart building technology are best realised by integrating multiple solutions—such as optimising asset runtimes based on changing energy prices, or on-demand ventilation controls that adjust heating and airflow based on the current conditions.
Smart technologies are beginning to transform tall buildings around the world, and we look forward to seeing what the future for green office buildings holds.