ATHENS CONCERT HALL ROOF GARDEN CONSTRUCTION

The uncontrolled increase of urbanization has resulted in cities characterized by the lack of open spaces and vegetation. Roof gardening is considered as a unique opportunity to effectively create green spaces in an established city environment. The extension of Athens’s Concert Hall was built in a portion of the city park “Eleftheria”. The extension includes a library, two big halls and five smaller ones with storehouses, an atrium, a three level garage, and the connection with the underground railway. However, considering the tight urban planning and the lack of vegetation in the city of Athens, most of the Concert Hall was built below ground in an effort to recreate the original park after the construction. As a result, a roof garden totalling 2 hectares was created over the roof of the extension building of the Concert Hall. The particularity of the project consisted in the numerous mounds of the building shell, varying from 2% to 69% in slope, due to an effort to retain the moved surface of the original park. This work will focus on the decision making processes during the selection of the drainage systems and the soil substrates for different parts of the green roof, as dictated by the different slopes and loading capacities of the building shell. Due to the steep inclination of some parts of the roof, reinforcing and stabilization techniques were necessary. A combination of soil reinforcing nets in conjunction with geocomposite honeycomb material was utilized to prevent soil movement and slippage as well as surface erosion. Stabilization of big tree specimens was performed with underground anchorage provided by concrete donut-shaped constructions. The biggest roof garden in Greece has been constructed so that it can host multiple functions without aggravating the city environment and will surely improve the life quality of the citizens of Athens.