The backbone of a smart building

Why smart buildings need a digital twin to realize their full operating potential.

Smart buildings have many advantages. But what technologies are behind them? And considering the rapid pace of developments these days, how can one ensure that a building doesn’t become technologically obsolete but can keep adapting to new requirements in the future? The decisive factor is how to plan and handle a building’s data with an eye to future needs. The concept of the Building Twin is the key to meeting these needs.

Digitalization enables smart buildings to understand their surroundings and interact with their users. The key here is data. Lots of data. “In the past, it was all about connecting a few dozen data points in a building. Today, we’re usually talking about tens of thousands, sometimes even hundreds of thousands of data points,” says Andrea Hofmann, Product Manager, Building Twin, at Siemens. The trend: upward.


Everything that’s going on in a building is being monitored and recorded with ever greater precision: building technology systems, electrical installations and thousands of sensors continuously deliver information about things like the current status of the systems and general conditions within the building. This data can then be used to save energy, optimize the comfort of those in the building or ensure maximum security. But even more is possible. “We believe that in a few years buildings will be able to adapt themselves to human needs,” says Andrea. 

The Building Twin bridges the gap between the building’s architecture, the placement of the devices and sensors throughout the building, and the data they produce.
 Andrea Hofmann, Product Manager, Building Twin, at Siemens

Building a bridge to the physical world

Until recently, one of the problems that stood in the way of further developing building intelligence was elementary: A building is far more than just a collection of technical systems, devices and sensors that collect and deliver data. A building has physical walls, a facade and specific spatial structures. Its rooms are generally individually equipped and furnished. In short: A building is primarily a physical body, and not a digital sequence of zeros and ones. So the question is: How can this type of physical information be translated into a language spoken by sensors and actuators? Into a language that’s also understood by a machine?


Increasing numbers of buildings have been planned digitally over the past decade. With the help of BIM (Building Information Modeling), digital building models can be created and provide the basis for the digital twin of a physical structure. With such a twin, all aspects of a construction can be planned and optimized before the first stone is laid. Such a digital model ideally contains all static structural data, such as room dimensions and the exact positions of doors, windows, cables, pipes, and all devices and sensors.

Digital twin for a building’s operation

Does this solve the problem of a building’s machine readability? Yes and no. BIM can in fact provide significant added value in planning and constructing a building. Yet these digital models are generally specialized to meet specific planning and construction requirements. “If you want a digital twin that’s also suitable for optimizing a building’s later operations, you need other and more detailed data in machine-readable form,” says Andrea Hofmann. In the future, builders and investors should ensure that a digital twin is included in the planning phase if it is to play a role in the building’s later operation. 

There are plenty good reasons for doing this. “Over the entire lifecycle of a building, some 80 percent of its costs occur in the operating phase,” says Andrea. “This phase obviously offers the greatest lever for savings.”


To utilize this potential, Siemens has systematically developed the idea of a digital building model with the Building Twin and optimized it for a building’s operating phase. The goal was to create a digital building representation that combines dynamic data, such as generated by the technical systems, with the building’s static structural data. “The Building Twin bridges the gap between the building’s architecture, the placement of the devices and sensors throughout the building, and the data they produce,” says Andrea. 

Knowing where

This combination of static and dynamic data creates a multitude of new application possibilities. With it, facility managers can no longer “only” identify malfunctions, but localize these malfunctions precisely in the building and analyze them directly on the screen. This substantially speeds up troubleshooting and enables refined, optimized predictive maintenance.   


Since the smart building not only knows how many people are inside, but exactly where they are, it’s possible to focus functions on the user: lighting, heating, air conditioning can be precisely adjusted to actual needs and even on the personal preferences of the users.  

The way which data is linked and how always depends on the respective application and the benefit expected of it.
 Andrea Hofmann, Product Manager, Building Twin, at Siemens

If one analyzes data from a building’s use over a certain period of time, one can find out whether there are areas in the building that are scarcely used. This specific information can then be used for purposes like planning the building’s cleaning tours. Or it can lead to redesigning unpopular spaces or use them differently.   


In the end, of course, these are just examples. The real point of the Building Twin is that the data can be used however the building users desire or require. “The way which data is linked and how always depends on the respective application and the benefit expected of it,” says Andrea. This approach is open and future-proof: New applications can be developed at any time and with reasonable effort.

All data in one place

The Building Twin concept obviously can reach its full potential only when all of the building’s data is stored and accessible in one place. The Building Twin thus functions as a central database in which all information is stored that was previously kept and maintained in different, application-specific databases. Ultimately, then, the Building Twin serves as the “single source of truth” for the entire building – a reliable and easily accessible source for all building information: the true backbone of future smart buildings.


Picture credits: Siemens AG

Subscribe to our Newsletter

Stay up to date at all times: everything you need to know about electrification, automation, and digitalization.