TOPGREEN green roof system

The professional way to turn your roof green

The largest pitched green roof in Europe in Rijswijk, NL


The municipality of Rijswik has built a pitched roof with a length of 120 meters on the roof of the "Ottoburg", an old school building from 1912.

The size of the project, combined with the high roof pitch of up to 45 °, is unique in the Netherlands and Europe. On behalf of Frima Begroeningstechniek Joru Support, atka supplied its TOPGREEN green roof system as a basis for greening with sedum mats from Sempergreen. The roof renovation is part of the sustainable policy of the municipality of Rijswijk.

Subsidy for green initiatives

In 2017, "Ottoburg" was transformed into a cultural and social center, housing, among other things, a day care center and a primary school. The former school building was to be thoroughly renovated after more than a hundred years. This refurbishment began in February 2018 and the construction of a sustainable green roof should play an important role. For this purpose, the "Ottoburg" received funding from the Sustainability Fund of the municipality of Rijswijk.
The community has set up this fund to implement green initiatives by businesses and local residents.

The size of the project is unique in Europe

A project with a green pitched roof of this size is unique in Europe. The height and inclination of the roof, combined with all the details, made it to this complex project. A good construction of the green roof is essential here.
The used green roof system TOPGREEN by atka consists of different "layers". The topmost and most visible layers are the sedum matrix mats, which lie on a layer of green substrate, a nutrient-rich soil especially for sedum plants. The substrate in turn finds its place and hold in the TOPGREEN green roof tiles GDP 45, with its special honeycomb structure, the substrate and planting is securely held on the roof. Even with high roof pitches. By a lattice construction under the pan, comparable to the construction of an ordinary tile roof, the whole system is protected against slipping.

The "green ceiling" on the roof of the "Ottoburg" covers no less than 2,000 square meters. For vegetation of this type, Sedummix mats "Type T" from Sempergreen are used. These consist of 10 to 12 different types of sedum. The sedum mat has a reinforced carrier that keeps the mat in place; an ideal solution for pitched roofs. The roof of the historic building has roof pitches of 40-45 °. Placing sedate mats is always a special challenge here.


Project Details

Client: Gemeente Rijswijk
Construction Management:LVD bouwmanagement
Roof management:Fier Dakcontrol
Green Roof Managementt:Begroeningstechniek Joru Support
Roofer:Klomp Daktechniek
Installer: Gustaaf Groenspecialisten
Fall Protection: Flesst
Sedum suppliert:Sempergreen BV
Green roof system: TOPGREEN
Source picture and text: Sempergreen BV

In a time of major climatic changes it is becoming increasingly important to build in an environmentally friendly way which preserves resources. The TOPGREEN green roof system from atka makes an important contribution to this objective. Professional roof planting restores to nature vital green areas which have been lost because of building. Harmful materials are bound and filtered, rainwater retained and heavy downpours flow away evenly.

Green roofs also stand out for their excellent heat insulation in comparison to a conventional tiled roof. They also absorb annoying airborne noise and protect your home against potentially harmful weather effects such as ice and hail.

The TOPGREEN green roof system can be installed on both flat roofs and pitched roofs with an inclination of up to 45°, setting no limit on creativity, either for the renovation of existing roofs or the construction of new houses with an environmentally friendly green roof. Under a green roof, this creates a calm and relaxing atmosphere, which has a soothing effect on you personal well-being.

TOPGREEN green roof system – the professional way to turn your roof green.
More Information: Heinze

atka Kunststoffverarbeitung GmbH
TOPGREEN Gründachsysteme

Südring 25
49393 Lohne (Oldenburg)

Phone: (04442) 9268-0
fax: (04442) 9268-11