The new research building of the Santa Creu i Sant Pau Hospital has been built inside the hospital compound, located in the city of Barcelona. The new building is linked to those already in existence by a walkway at second floor level, which will facilitate the flow of people between the premises. A large metal structure of bars in a spiral tube shape that connects the two buildings and is covered by a perforated membrane.  The perforated fabric is see-through both from the inside and from the outside. The walkway DNA with the double helix spiral is transmitted in an exceptional way with the single-piece continuous membrane.