Saving energy with networks: how smart buildings are becoming more efficient – together

We spend 90 percent of our lives in buildings, says Rainer Haueis, Head of “Buildings” at Siemens Smart Infrastructure. He explains how digital and AI-driven technologies are making buildings smarter – with the goal of using energy more efficiently, automating processes and lowering operating costs. What excites him most is the smart tech you don’t see: “The greatest compliment for us is when building users don’t even notice everything we’re doing behind the scenes to achieve more energy efficiency, sustainability and comfort.”

Building lifecycles are long – we’re talking 30 years and more. When we say “smart,” we mean solutions that help run a building more efficiently, from planning to demolition. The discussion often focuses on construction, but three–quarters of energy consumption is during operations. That’s exactly where we can optimise.

In addition to traditional approaches like insulation, digital solutions for building systems have emerged in recent years, right up to the cloud. Sensors and actuators – capturing conditions and triggering actions – are what make buildings energy efficient and sustainable.

Almost anyone can stick a wireless IoT sensor on a wall that captures data like temperature or humidity and sends it on. With that information, you can start small at home and gain transparency into what you consume and where you can save.

The same applies to large facilities. You can control office lighting via sensors –  the light only turns on when a desk is actually occupied – or manage shading – the blinds lower when the sun is out. And when access control systems tell you how many people are in the building and how they move, you can pass that information on. In the elevator you might then see: “Cafeteria currently at 98 percent capacity.” And you might decide to eat a bit later.

You don’t always see the tech, but it’s there, doing something. That’s how buildings become “intelligent.”

Of course there are data privacy questions: How long is data stored? Is it personalised? And much more. Company policies, the works council, approvals – we’re subject to these rules, just like our customers. But we’re not trying to archive data. We don’t want to generate personal data; we want to create value. By intelligently linking all this information, you can unlock the next 10 – 20 percent in energy efficiency.

Cybersecurity is our top priority – and not just in theory: we develop our own solutions for smart buildings and help operators make their systems more secure. Our experts have designed a specialised method we call the Cybersecurity Gap Assessment. It shows where vulnerabilities exist and provides recommendations that are immediately actionable. The resulting report delivers full transparency across all technical systems and weaknesses – including concrete measures.

Naturally, we keep our customers’ systems up to date, ensure they meet regulatory requirements, and protect them as effectively as possible against attacks.

Take the pharma or semiconductor industry: there are “clean rooms” that need very specific conditions, like positive air pressure to keep dust out. Suddenly, building technology sits at the heart of the production process. It’s about preventing downtime, operational safety and availability.

Or consider a completely different example: museums also require very specific conditions – think of paintings. Or paper, where humidity is crucial. One example is the Berlin State Library where we reduced energy consumption by 52 percent. The measures also led to a CO₂ reduction of 3,745 tons per year and around 20 million euros in guaranteed savings over ten years. 

Intelligent data use for optimum resource deployment – that’s the key!

In hospitals, building technology isn’t just a side note either. The biggest cost factor there, alongside personnel, is whether the medical infrastructure is being used to the optimum. Our colleagues at Siemens Healthineers offer models where you don’t buy equipment anymore – you pay per use.

If you know, by smartly linking information, how many patients are coming and how beds are occupied, you can manage staff and equipment better and deploy resources much more efficiently. Take an MRI scanner: if I understand its utilisation and connect that with building data, I can cut waiting times and run the operation more efficiently.

In short: intelligent data use for optimum resource deployment – that’s the key!

The big challenge is the sheer amount of data. How do we bring it together? Many stakeholders in construction keep data in their own systems or clouds. If we link these sources, couple generators and consumers intelligently, and use forecasts – we can squeeze out even more efficiency.

Many large customers – industry, airports, hospitals – now have photovoltaics alongside traditional energy supply. They have backup power systems for emergencies, combined heat and power (CHP) units and battery storage. Generators already work together intelligently. We asked ourselves: how can we make consumption smart, too? There are good solutions for individual buildings to manage loads intelligently. But it really packs a punch when you bundle multiple sites.

With a so–called microgrid controller, I can coordinate various energy loads across the system. Take an airport, for example: imagine all the different things that run on electricity. E-buses, for instance, moving backwards and forwards across the apron. If a chiller kicks in for half an hour somewhere else at the airport, it's no problem. Granted, it generates a lot of waste heat, but in a large, connected system that heat is captured and used elsewhere immediately.

The more buildings in my network, the more options I have – especially if I can also tap the external grid outside the microgrid.

A very exciting municipal project is Siemensstadt in Berlin, part of our company’s history. We have plans to install a heat exchanger in the sewers – one kilometer long – and use that heat to warm our buildings. I find that fascinating.

Or data centres: you can use the waste heat from all those servers. We call this sector coupling,  “power–to–X.” It doesn’t matter who the end consumer is – electricity to hydrogen, hydrogen to heat, hydrogen to electricity.

It is. That’s why simulation, testing, and optimisation before construction are so important. We plan such projects using a digital model – a digital twin – that involves all stakeholders, pulling in a wide range of data and information, from building models to climate data to potential consumption profiles. That way, energy flows can already be accounted for at the planning stage.

No human can process all that alone – you need software and AI.

No human can process all that alone – you need software and AI. Once the asset is built, we use real–world data to keep optimising. It works very well – we’ve had a 100 percent hit rate.

The best energy is the energy you don’t use. We try to cut consumption by making the most of the energy available. That typically improves our customers’ CO₂ footprint and helps them reach their climate targets.

Municipalities are increasingly focused on this. For example, we’ve entered an innovation partnership with the public utility company in Stuttgart. Electricity, heat and mobility are being linked across sectors – a showcase for an urban energy transition. We support with our technology, innovations and expertise. Unlike us, municipal utilities also serve private end consumers – which we don’t – so it’s a win–win.

Another great example of a partnership with a municipal utility is the one in Wunsiedel. It might be small, but it’s extremely innovative and visionary in hydrogen production. Partnerships like these are essential to break data out of silos and use it broadly and to best effect.

What’s crucial is that we move faster overall – especially with smart grids and sector coupling across electricity, heat and transport. When wind power in the north is curtailed because there aren’t enough lines to the south, you see where speed is needed. A lot is happening – but not nearly enough.

Regulation helps get certain things moving – and in residential construction, subsidies really are an incentive. But generally: if a solution pays back quickly, investment willingness rises significantly.

For our own large sites, we accept longer payback periods of five, six, seven years – otherwise many sensible measures would fall victim to strict ROI criteria. For our customers, we’ve developed new concepts. For example, we work with energy contracting. We assess current consumption, then design an efficiency concept and calculate savings, costs and financing needs.

Think of it like this: the customer asks, “Where do I get the 2 million euros for the investment?” We say, “We’ll front the 2 million, and we’ll share the money from the energy you save.” Once everything’s paid back, the customer gets the full benefit. In short: the savings pay for the investment. That’s win–win–win.

Next up is the autonomous building. Linking everything we’ve talked about, powered by AI. The goal: the building responds to changes on its own and detects issues before they even occur.

Next up is the autonomous building

We’ve already talked about buildings ingesting weather data – automatically adjusting heating or cooling. Predictive maintenance goes even further: as we know from mobility, sensors and AI analyse data, recognise patterns – say, when a motor runs harder or power draw increases – and alert you before something fails. You don’t change your car’s oil filter on a fixed schedule; you change it exactly when it makes sense. Buildings will work the same way.

We call it technology with purpose – technology that serves a meaningful goal and makes everyday life better.