柏林城市学校成立于2004年，是柏林Mitte区最早的国际学校。为贯彻其先进的教育理念同时容纳新开设的高年级课程需求，学校联合Sauerbruch Hutton开展了此次扩建计划。

Berlin Metropolitan School was founded in 2004 and is the oldest international school in Berlin-Mitte. In order to implement their advanced educational concept and accommodate the recently established senior classes, BMS needed additional floor space.

▼项目一览，overview © Jan Bitter

学校被容纳在一座于1987年东德时期建造的预制建筑当中，采用了“Schulbaureihe 80”的建筑类型。大楼的四个体块在街区中心围合出一个开阔的学校庭院。本次方案最终确定对三座现有建筑的屋顶进行扩建，同时加建一处与地面连接的附楼；此外，项目还需额外增设教室、音乐室、一个可通往屋顶花园的图书馆、行政办公室以及一个举行重要活动的大型礼堂。

BMS is housed in an existing prefabricated building from the GDR era that was erected in 1987, using building types of ‘Schulbaureihe 80’ (SBR 80, Typ Erfurt). Four building sections cluster around a generous schoolyard inside the block. The scheme consists of rooftop extensions to three of the existing buildings, as well as an annex which wraps down to meet the ground level. The programme includes additional classrooms, music rooms, a library with access to a roof garden, administration offices, and a large auditorium where the main events of the school year will be held.

▼从庭院望向学校建筑，view of the building from schoolyard © Jan Bitter

由于工程作业需伴随上课时段进行，且过程中需要根据需求逐渐增加建筑面积，因此，设计团队在扩建部分采用预制木材系统进行分阶段作业。预制木材在其自重较轻的优势下，无需增加额外的地基或改动现有支撑结构，十分便于在各项目阶段进行快速安装。

The construction work had to be executed during school hours and realised in stages, according to the gradually increasing need of floor space. Therefore, the extension has been designed as a prefabricated timber system that could be quickly erected in phases. Owing to its low own weight, the timber construction does not require additional foundations or alterations to the existing supporting structure.

▼设计概念，the concept © Jan Bitter