What is energy intensity & why is it important?
Energy intensity has long been touted as the most effective way to measure – and thereby reduce – energy usage across the entire real estate sector, but what is the measure, and what do property investors need to know about it?
The real estate sector accounts for more than one third of global energy consumption and emissions, according to 2022 data from the International Energy Agency (IEA). Direct emissions from buildings decreased in 2022 compared to the year before, despite extreme temperatures driving up heating-related emissions in certain regions. However, in the same year, building-sector energy use increased by around 1%.
Minimum performance standards and building energy codes are increasing in scope and stringency across the globe, and the use of efficient and renewable buildings technologies, such as Workman’s Intelligent Building Operating System (IBOS) is accelerating.
Yet the sector needs more rapid change at greater scale if it is to achieve Net Zero emissions by 2050, as set out by the UK Government. The IEA describes this decade as “crucial for implementing the measures required to achieve the targets of all new buildings and 20% of the existing building stock being zero-carbon-ready by 2030.”
What is energy intensity?
Energy intensity represents the energy consumed to operate a building, relative to its size. It’s an increasingly essential metric, as it reflects the amount of energy consumed per unit area of a building, typically measured in kilowatt-hours per square metre, per year (kWh/m²/year).
It’s considered a comprehensive indicator of energy efficiency, with higher energy intensity suggesting inefficient energy use. The energy consumption measured typically includes heating, cooling, lighting, ventilation, and the operation of electrical devices.
Why is it important?
This concept is key to evaluating the energy efficiency of buildings and identifying areas for improvement. As buildings account for more than a third of global energy consumption, understanding and measuring energy intensity effectively is key to reducing environmental impact and enhancing sustainability.
The metric is influenced by a range of factors such as the building’s design, construction materials, insulation, the efficiency of installed systems (such as HVAC), and occupant behaviour. For example, a well-insulated building in a temperate climate with energy-efficient lighting and appliances will almost certainly have a lower energy intensity than a poorly insulated building in a harsh climate that relies on outdated systems.
Calculating energy intensity at a company or property level can help monitor changes over time, which can help organisations set targets and policies. It can also allow for comparative analysis across different sectors, which can help identify best practice, and pinpoint areas for improvement.
Accurate measurement of energy intensity is necessary to ensure compliance with government and industry standards. For example, the UK government set national carbon reduction targets through the Climate Change Act 2008, including reduction of 68% by 2030, 78% by 2035, and compared to 1990 levels, reduction of 100% by 2050.
How does IBOS help analyse and reduce energy intensity?
To effectively measure energy intensity, a systematic approach is required. The first step is to gather data on the total energy consumption of the building, which should include all forms of energy used. Next, the total floor area of the building should be accurately measured, accounting for all spaces that benefit from lighting, heating or cooling.
Continuous monitoring, optimisation and analysis allows building managers to track changes over time, assess the impact of energy-saving measures, and identify new opportunities for improvement. Intelligent systems such as Workman’s IBOS can automate this process, providing real-time data and analytics, which are adjusted to account for a building’s occupancy patterns.
Lowering energy intensity through efficiency measures can lead to substantial cost savings over time. For example, IBOS – now installed across more than 9.2 million sq. ft of commercial property – has delivered £6.5m of savings on clients’ energy bills to date, saving 31,200,000 kWh of energy and preventing 3,400 tonnes of CO2e from entering the Earth’s atmosphere at the 97 buildings where IBOS is installed.
Effective measurement of energy intensity requires comprehensive data collection, normalisation for external factors, ongoing continuous monitoring, and benchmarking against similar buildings.
Call for more nuanced measurement frameworks
In terms of benchmarking, there is a need for industry-wide action, as standard marker data and targets for certain niche, smaller-sector building uses doesn’t currently exist. Therefore, comparisons for submission to industry standard frameworks such as the Carbon Risk Real Estate Monitor (CRREM) or London Energy Transformation Initiative (LETI) can often be fraught with inaccuracy in real terms.
An example of this would be office-type buildings that are partly used for laboratory space; the use of laboratory space in a building increases energy consumption due to the nature of work being undertaken in this space, but the only available comparisons would be true lab or office building usage. So, the mixed-use assets either seem to be performing very poorly or overly well in benchmarking or target-based assessment. Similar issues are found with shopping centres, due to common parts versus total-building-size metrics. The system needs to be tailored in order to take these nuances into account, so that true energy intensity measurement becomes possible, accurate, and reliable.
As the world moves towards more sustainable energy practices, understanding and optimising energy intensity in buildings is predicted to play a vital role in achieving broader energy efficiency goals.
To find out more about how our Building Technology team can help, or to arrange a demo of IBOS, contact James Hallworth.