The Spice Shopping Centre in the Latvian capital of Riga has employed a unique construction technology innovation known as a Ruukki Smart Roof. Ruukki Smart Roof is system that monitors snow weight on the roof and produces information about any changes in real time information of its changes.
Automation reduces risks
“We wanted an automated system that provides us with information about the snow load on the roof in just the same way as we receive information about the indoor temperature, for instance,” explained Andris Stankevičs, Technical Director at real estate company E.L.L. Kinnisvara.
Andris Stankevičs says that although the depth of the snow on the roof can be measured manually, there is always a risk of human error. Snow has been measured in wrong spot on the roof, in the wrong way or a perhaps a person doesn’t know how to measure it properly.
Depending on temperature, the snow structure and water content can differ even within one day. This has a great impact on the weight of snow on the roof. It’s more important to know the weight of the snow than how thick the snow layer is.
Savings, safety and peace of mind
Ruukki Smart Roof means savings for facility maintenance. The system sends an alert when, for safety reasons, it is time to remove snow from the roof. Savings arise since snow does not need to be removed from the roof unnecessarily. Snow is often snow is removed unnecessarily because the weight of the snow is not known.
“Smart Roof is also cost effective; it can be installed for the areas of highest risk. In the case of Spice, the locations for sensors was designed together with structural engineering’s and Ruukki’s experts,” said Andris Stankevičs.
Smart Roof is also an investment in the safety of both life and property. A building where snow load is automatically monitored and removed based on real-time data is far safer than a building using the conventional solution - manual snow removal.
“Safety is also part of our image. Customers visiting and shopping in Spice do not have to keep their eyes on ceiling and worry about the centre not being safe. This is safe. We have always done things differently, making use of the latest technologies, of which Ruukki Smart Roof is one,” explained Andris Stankevičs.
Technically the only possible way
Ruukki Smart Roof was the smartest solution for Spice even from the structural point of view.
“It would have been almost impossible to reinforce the roof trusses in a cramped space full of cables. That would have resulted in having to close the entire shopping centre, or at least part, while the work was being carried out,” said Stankevičs.
Andris Stankevičs added that even if it were possible to replace or reinforce the trusses, they would still need to know the real load-bearing capacity of the foundations of the pillars. Structural changes during the construction phase are often not documented and only the original design phase documentation is available.
Sensors attached to the critical points
There are a total of four snow load measuring units, radio boxes attached to the underside of the roof. These sensors are located right next to the highest part of building, where snow banks can form. Each radio box has a temperature compensator and three sensors to measure the load on the roof. The sensors are connected by cable to a radio box and measure the load every 60 minutes.
The radio boxes transmit signals to a wireless gateway, which sends a signal to a central server via a mobile connection. The server is an information core that sends information to users and if necessary an alert. Information and alerts are sent both as emails and SMS. In the case of Spice, the technical director can monitor Smart Roof from a computer screen in his workplace, just as with any other application. The interface gives numeral and graphical information.
First be prepared, then act
Two limits have been determined for the system depending on the building structures and capacity of the load-bearing sheets. In practice, the top limit, 100 %, means the load capacity limit of the roof. In the case of Spice, a 50 % alert means that the personnel needs to be ready and prepared to remove snow if more accumulates. This alert level is transmitted via emails and is also visible in a web interface. Spice has set the system so that the alert for 50 % of the top limit is visible to internal users such as the technical director.
When the snow load reaches 75 % of the critical point, the system sends the next alert. This time users also receive an SMS. An alert for 75 % goes also the facility service company that can start removing the snow immediately.
Alerts are sent after two measurements. This ensures that the situation really requires action and that the alert is not caused by error. A quick change in air temperature or pressure can sometimes give false data.
Smart system and great attitude to service
“We studied various possibilities to monitor the snow load on the roof and Ruukki’s system appeared to be the best. Also the service and attitude that company shown influenced our choice,” explained Andris Stankevičs.
He said that they would have liked to have used the Ruukki Smart Roof system in their other shopping centre in Riga. That was unfortunately not possible because Smart Roof works only in conjunction with load-bearing sheets provided by Ruukki. Ruukki knows the properties of its own steel sheet and can guarantee the right functionality of Smart Roof.
Spice Shopping Centre is about 5 kilometres from the centre of Riga. It was opened in 2001 and is now one of the most popular shopping venues in Riga, attracting approximately 8 million visitors a year.
The complex is in two parts: Spice and Spice Home, with around 200 shops and restaurants. The combined area of both would be about the same size as eleven mid-size football pitches.
Spice is a working place almost for 700 people.
Estonia-based E.L.L. Kinnisvara is one of the largest real estate developers in the Baltic State and is mainly involved in developing commercial real estate in the roles of developer, investor and property manager. The company owns 8 shopping centres, 3 hotels, 14 office buildings and 7 other types of real estate properties. E.L.L. employs around 50 people in the group’s Estonian, Latvian and Lithuanian companies.
Think out-of the box
Andris Stankevičs said that they like to do things differently and use of Ruukki Smart Roof reflects this. He showed how a car park can be built more ecologically even though motoring is far from ecological. Here, too, the ideology was sustainability, the environment, economics and elegance.
The car park has been paved with slabs that can also be recycled in future if the car park next to Spice is no longer needed. If the area needs to be excavated, it’s easy to repave it seamlessly. Parking places are not painted, but demarked using lighter slabs. The parking area tilts towards the west. Trees and shrubs absorb 75 % of the rainwater and there are gaps in the paving around them to allow water to flow to the plants. This car park will not flood the Riga sewer system in sudden downpours. No trees were felled during the construction stage, instead they were either left in place or replanted elsewhere. When it’s dark, the area is lit up by led lights and there are also charging points for electric cars.
“This is a much more elegant and ecological solution and cost no more than a conventional car park,” said Andris Stankevičs.