The Role Smart Buildings Will Play in the Energy Transition

With net zero deadlines fast approaching, Siemens, Honeywell and Johnson Controls are harnessing AI to make buildings active participants in the energy transition.

For years, so-called ‘smart’ buildings revolved around motion sensors and timed heating controls.

Now, advances in IoT, edge computing and Gen AI have transformed them into responsive, energy-aware systems – able not only to react to occupancy but to learn, adapt and optimise their energy performance.

With around 40% of global carbon emissions coming from the built environment, regulators are tightening efficiency requirements.

Operators of older infrastructures face urgent pressure: reduce consumption, or risk both non-compliance and mounting energy costs.

The solution increasingly lies in digital retrofits rather than demolition. Much of the existing building stock is connected by outdated, power-hungry systems.

Tools like digital twins offer a route to modernisation, enabling managers to test configurations virtually and fine-tune real-world performance.

Once energy usage can be simulated in real time, buildings shift from being passive energy consumers to dynamic energy assets.

How Siemens is connecting buildings to the grid

Siemens’ strategy centres on openness and interoperability. Through its Siemens Xcelerator platform, the company is creating a foundation for energy-smart transformation without vendor lock-in.

At the core of Siemens' strategy is Building X, a cloud-based suite that unifies all manner of building systems, from HVAC and lighting to power metering.

“Building X breaks down barriers,” says Matthias Rebellius, Member of the Managing Board of Siemens AG and CEO of Smart Infrastructure.

“We can now combine all data generated by systems in smart buildings into a single data pool. This allows us to realise smart buildings faster and brings us closer to our vision of autonomous and climate-neutral buildings.

“Building X creates measurable data-based results regarding efficiency, performance and user experience. In this way, Building X improves how we work and live in buildings.”

Central to Siemens’ vision is the grid-interactive building – one that not only draws power but also generates and stores it.

Using AI-driven predictions of energy loads, Siemens enables commercial estates to flatten peaks in demand, lower operational costs and contribute to grid stability.

How Honeywell is shaping smart buildings

Best known for control systems, Honeywell’s energy journey now revolves around Honeywell Forge, its enterprise performance management (EPM) SaaS platform.

Forge overlays intelligence on existing infrastructure, creating a continuous feedback loop between data analysis and building control.

Using machine learning, it adjusts HVAC settings and lighting dynamically based on weather patterns and occupancy – minimising wasted energy and associated emissions.

“Building operations is evolving at a rapid pace as many customers work to digitalise their facilities," says Kevin Dehoff, Honeywell’s Chief Strategy Officer.

"This means they need better integration and enablement capabilities of their smart building applications and solutions.

“We are integrating our purpose-built products that support multiple assets in a building with the SaaS capabilities of Honeywell Forge to create a singular approach to building operations.

“The goal is to make it simpler for our customers to address business-critical outcomes.”

Energy efficiency isn’t Honeywell’s only metric.

Its ‘Healthy Building’ model also puts energy performance in context – balancing HVAC efficiency with air quality and occupant well-being.

Its systems can track particulates and VOCs, then adjust airflow automatically to maintain both safety and power efficiency.

How Johnson Controls is redefining energy efficiency

At Johnson Controls, the convergence of energy technology and sustainability is embodied in its OpenBlue platform – a scalable system combining AI, data security and operational insight to cut both costs and carbon.

Its 'Net Zero Buildings as a Service' model means companies can decarbonise without relying on internal capital expenditure, paying instead through the energy savings they generate. The OpenBlue ecosystem links every stage of the building lifecycle – from design to operation – to continuous energy performance monitoring.

George Oliver, Chairman of Johnson Controls, says: “The need for making net zero leadership easier to achieve is immediate and greater than ever.

“Buildings represent about 40% of global emissions and Johnson Controls is uniquely positioned to help customers around the world pursue their net zero carbon goals.

“Our As a Service model looks to provide our customers with guaranteed outcomes and risk management models to achieve emission reduction commitments that ultimately lead to healthier buildings, people, places and the planet.”

By combining its long-standing expertise in chillers and HVAC with predictive AI diagnostics, Johnson Controls can identify faults weeks before they occur. Preventing these inefficiencies keeps systems operating at peak energy performance and ensures that every kilowatt is used as efficiently as possible.