Sustainable roofing for Aarhus’ new light rail system

LESSNOX AND GREEN ROOFS ARE THE OBVIOUS SOLUTION FOR COMPANIES WITH A CLEAR ENVIRONMENTAL PROFILE.

“Sustainability and a green profile are key characteristics of Aarhus Letbane (Light Rail) and the City of Aarhus, which targets being CO2-neutral by 2030. Accordingly, we have tried to take the environment into consideration in several parts of the light rail system – including the construction of the system’s traffic and service centre,” says the head of Aarhus Letbane, Claus Rehfeld Moshøj.

With this objective in mind, the choice fell on Phønix Tag Material to supply two green products: LESSNOX, as part of a two-layer solution, and Nature Impact® Roof. The latter is a sedum lawn sown across the 5,000 square-metre roof covering the workshop and the traffic control office.

“This insulates, delays and reduces rainwater runoff and, as a further positive effect, the roof provides a haven for bees and other insects in the local environment,” says Claus Rehfeld Moshøj.

A corresponding 5,000 square-metre area for the marshalling and maintenance of the trams has also been provided with a roof that integrates environmental thinking.

“Here we have used a LESSNOX coating that, to a certain extent, absorbs harmful nitrogen oxides (NOx particles). At the same time, we collect rainwater to be used for washing the vehicles. Both parts work very well and help show that light rail is a modern and environmentally friendly means of transport,” says the head of Aarhus Letbane, Claus Rehfeld Moshøj.

LESSNOX ROOF REDUCES NOX EMISSIONS IN THE RANGE OF ABOUT THREE PERCENT.

The new buildings were designed by GPP Arkitekter A/S, and the green sedum roof, in particular, is a clear visual reference point, according to architect Niels Haugård.

“The building and its roof can be seen clearly from the Ringgade Bridge, which thousands of road users pass every day. Accordingly, a green roof that shifts in its expression is an obvious visual solution, and one that also works well with the surroundings. You see not ‘only’ a roof, but a green, living area,” he says.

Besides being green and beautiful, the colour of the roof changes with the seasons. At the same time, it collects and slows down rainwater, relieving the waste water system of a number of cubic metres of rainwater each year.

The roof was installed by Karl Aage Jensen Takdækning A/S and, for its owner, Günther Staugaard, this was the first time the company’s employees worked with Nature Impact® Roof. But certainly not the last:

“Working with the material was incredibly fast and easy. Of course, we had seen and heard about it before, but this was the first time we used it, and we will be happy to perform similar work in the future. One of the most obvious benefits is that roofers can work alone. You don’t have to have numerous people at the site, making installation highly efficient. At the same time, deliveries adhere well to the schedule, so we always have something to work with,” says Günther Staugaard, adding that it took four men a week to install 5,000 square metres.

Aarhus Letbane will commence operations in the spring of 2017, when the first line from the central station to Lisbjerg opens. In the autumn of the same year, the entire light rail system will be completed, with the lines extending from Grenaa to Odder. Constructing the traffic and service hub has a cost a total of approximately DKK 200 million, with Gråkjær A/S is the general contractor.