Sustainability and digitalisation must go hand in hand when revitalising old buildings

This is a debate piece brought in Byrummonitor on 08.01.2026, written by Gitte Gylling Olesen, Sustainability Director, COWI, and Niels Treldal, Senior Market Director, COWI

Applying digital perspectives, we can transform existing buildings into living, adaptable systems, argue Gitte Gylling Olesen and Niels Treldal, COWI, in this debate piece.

By marrying sustainability ambitions and digital perspectives, we can transform existing buildings into living, adaptable systems, believe Gitte Gylling Olesen and Niels Treldal.

Climate change and environmental challenges are forcing us to rethink many aspects of our society, and the existing building stock plays a vital role in that. Buildings and their operations account for a considerable share of Denmark's total energy consumption and CO₂ emissions; around 23%.

With huge impact comes an obligation

Simply refurbishing buildings, with an eye for aesthetics, resources and energy consumption, does not cut it. Long-term durability requires visionary and holistic strategies for operations, use and flexibility. It also requires understanding the function and architectural intentions of the original building.

When we renovate and reuse buildings, we considerably reduce the environmental impact. Not only by minimising material consumption and avoiding large quantities of construction waste, but also by creating renovated buildings that actively limit the energy consumption of daily operations compared to the energy footprint of the original building.

Applying a holistic operations strategy is crucial to ensure that the qualities of the renovation create a long-term perspective in which air quality, temperature regulation and energy optimisation all contribute to a greater whole.

The users' well-being, comfort and productivity are directly affected by the air quality, temperature, humidity and inflow of light in the building. A good indoor climate is not a luxury but a necessity to create an optimal environment. With that in mind, it is vital that buildings are developed with more than low energy consumption in mind; they must be complete solutions that merge environmental considerations and comfort.

How to translate ambitions into tangible actions?

To that end, digitalisation is a key factor. Without ambitious digital solutions – including intelligent control systems, sensors and data analysis – we risk energy optimisation becoming random or reactive measures rather than proactive and continuous improvement processes.

Technological solutions enable real-time monitoring and adjustment of building operations, identify energy-intensive installations and create a continuous feedback loop that constantly optimises.

A digitalisation strategy must be carefully thought-through. New possibilities in artificial intelligence make it possible to analyse much larger volumes of data from building sensors and, thereby, achieve a lot, even with limited operational resources.

When fitting out new buildings with sensors and intelligent systems, it is still important to balance installation costs and potential savings. AI continues to push the boundaries of what is possible, which makes a long-term perspective essential.

The potential exceeds mere technical operations aspects, though. In particular, it should also be used to record and measure parameters such as occupancy, time of use and extent. In that way, we can continuously uncover new optimisation opportunities regarding the climate, weather and seasons – as well as usage patterns, paving and frequency.

By marrying sustainability ambitions with digital perspectives, we can transform existing buildings into living, adaptable systems. Systems that balance considerations for environmental protection, economic efficiency and human well-being – both now and far into the future.

However, this calls for a goal-oriented strategy for the operations for reused buildings. Without a focused digitalisation effort, we risk losing the possibilities brought by both technology and our investments in renovation.

If we want to ensure that the buildings we transform also constitute principal elements of a greener and healthier future, sustainability and digitalisation must go hand in hand – from strategy to daily operations.