Ramboll - Merano Residences
Client - St James
Engineer - Ramboll
Architect - Rogers Stirk Harbour & Partners
Project delivery architect - EPR
Principal contractor - Expanded
Precast manufacturer - Explore Manufacturing
Tight site constraints and the requirement to minimise the construction programme led to Ramboll utilising the principles of DfMA (Design for Manufacture and Assembly) and designing Merano Residences as a precast structure to provide efficiencies in speed of construction.
The new structure consists of a hybrid precast reinforced concrete frame that is supplemented with external, steel cross bracing. The use of a hybrid approach allows external steel nodes to be cast into the insitu slab topping, thus taking the steel fabrication off the critical design path and simplifying the manufacturing process for the precast elements. The external steel bracing gives the building its unique architectural identity and provides permanent lateral stability (resistance against wind loading) and vertical support to the North and South elevations.
Prefabricated lightweight steel balconies providing external living space are located on the east and west elevations. A steel hanger truss system supports the balcony structures and provides a distinct external feature to the façade.
Client aspirations for large unobstructed column free living spaces led to the challenge of reducing the number of supporting columns to just 12. These were located in the external façade and form exposed precast feature columns, which are expressed as a dominant aesthetic feature for the full height of the building. At ground level, four storey high, corner columns provide a distinctive boundary line to the open external public space.
The large floor spans were achieved using a 310mm thick hybrid precast lattice and insitu floor system that is supported on precast columns that work structurally to provide a moment frame and limit deflections in the floor slabs. This resulted in complex floor to column connections that were developed to enable offsite manufacture.
The innovative use of 300mm thick precast twin walls above ground level, bearing directly on to the central stability wall in the basement reduced the requirement for propping and shuttering on site saving time, materials and labour.
Exposed precast black stair core walls to the rear of the building provided an aesthetic feature and gave additional stability to the structure.