Acclaimed fibre solution yields environmental gains in 600 schools

In Stockholm, there are 600 public schools and preschools, all of which are connected to the Stokab fibre network. Naturally, that gives all pupils and teachers access to fast and secure online access. But it also makes it possible for SISAB, the city’s school property company, to monitor and control the buildings from a central location, generating substantial economic benefits and reducing climate impact.

The temperature in a classroom at Globala, an upper secondary school on Södermalm, Stockholm, dropped to 16 degrees overnight. In the control room at SISAB's head office in Årstadal, south of the city, the school's icon glows red on the screen to alert the staff of the problem. The operations pilots can quickly localise the source of the fault – a ventilation unit that is not shutting off like it should – and make sure the service team fixes the fault.

Monitoring from controlroom

"We can see the status of all buildings from here in real-time. In addition to heating and ventilation, we monitor pumps, lifts, gates, fire alarms and more," explains Niklas Dalgrip, head of the operations department at SISAB, which manages Stockholm's 400 preschools and 200 compulsory and upper secondary schools, from Kista in the north to Farsta in the south.

Via fibre connections and property servers, all school properties in the network communicate with SISAB's data centre, where all the information is collected. Signals like burglar and fire alarms come in from the security system, while control and monitoring systems keep track of heating, hot water, ventilation, lighting and more. All information is transmitted via fibre and merged into the central management system that is monitored from the control room in Årstadal.

Niklas Dalgrip, head of the operations department at SISAB, with Mats Carlqvist in the controlroom at Årstadal.

"Because there is so much information to be transmitted, we need the capacity of fibre for this to work. No other technology can do it. We've chosen to rent 'dark fibre' to maintain complete control over our network."

The system issues a signal if pre-set limits are exceeded. Niklas Dalgrip compares it to the IT system in an air traffic control tower that monitors traffic and raises an alarm if an aircraft deviates from its planned flight path or altitude.

"Our system helps us focus and work with the right things. We can fix what's wrong and, not least importantly, optimise our facilities."

Reduced energy costs

Over the past five years, SISAB has invested SEK 100 million in systems and equipment to monitor the indoor climate, including the installation of 7,000 wireless temperature sensors in classrooms and other school premises. This has proven very profitable. The investment has generated savings of SEK 190 million in energy costs during the same period and reduced energy consumption by about 26 percent per square metre.

The monitoring system also provides an overview of necessary maintenance, which creates opportunities to plan the work of building technicians in an efficient way. For example, their travel can be minimised and maintenance can be planned for school holidays and study leave days.

According to Niklas Dalgrip, there are a lot more efficiency gains to be made. Above all, this will involve the continued optimisation of operation in relation to building occupancy. The premises must be in top condition when pupils and staff are present, but still save on things like heating and lighting when they are empty.

Ventilation by WiFi

Within a not too far distant future, for example, it will be possible to control the ventilation in upper secondary schools by measuring how many devices are connected to WiFi. That gives a rough indication of how many people are on the premises and ventilation can be adjusted accordingly.

"Now that we have gained access to so much data, we realise that there is much more to improve and major savings yet to be made. But the system does not come up with the solutions itself – for that, we need our skilled employees. It is the people who analyse what is happening and can be innovative in devising further improvements," Niklas Dalgrip concludes.

About Sisab

Logotyp Sisab

SISAB, Skolfastigheter i Stockholm AB, is a municipally owned enterprise that owns and manages the majority of preschools, compulsory schools and upper secondary schools in Stockholm.
Number of properties: 600
Total area: 1.8 million m2
Users: More than 125,000 pupils and teachers every weekday
Investments: SEK 2 billion annually in maintenance, new construction, extensions and rebuilds
Number of employees: 200
Owner: Stockholms Stadshus AB


The SISAB solution

  • All buildings are connected via fibre
  • A large number of meters/sensors were installed in the buildings
  • Control room with fully integrated systems for building monitoring
  • Operations system that graphically visualises the status of all buildings
  • The system enables rapid action and generates major economic and environmental savings

Stokab and the city’s digital strategy

Stockholms Stadshus

Stockholm's vision for digital development is that the city will be the smartest, most connected city in the world by 2040.


In a nutshell, that means Stockholm will be using IT to create the best possible quality of life for the citizens of Stockholm and optimal conditions for business.


The Stokab fibre network currently covers virtually the entire Stockholm region and is the foundation of the essential infrastructure for digital communication.


The fibre network is making a strong contribution to the city's growth and development in terms of business and the city's own operations. All schools and preschools in Stockholm have been connected to the fibre network for several years.