The Helmholtz-Zentrum Berlin plans a new building on the grounds of the institute in Berlin-Adlershof. The building will be constructed for BERLinPro, a project of the accelerator physics research. It consists of a technical and an accelerator hall. The accelerator hall is an underground bunker for a compact, recirculating electron linear accelerator with energy recovery. The complex technical challenges are the planning and realization of a high-current electron source of small emittance, the development of superconducting high accelerator activity and the realization
of magnetic optics for lossless beam transport while maintaining the high beam quality. During the construction special attention must be paid to radiation protection requirements, the high groundwater level, water drainage, fire protection and mechanical vibration for the storage ring BESSY II.