Adding Stories

Air Space Developments

Developers are increasing looking to maximise the potential of constrained sites by adding additional stories on top of or over existing buildings.

Whilst a site may be able to achieve planning permission for additional stories, it is not always technically feasible. As such, SD Structures are often engaged early in the design process to prepare a feasibility study.

The simplest solution in proving the structure can carry additional stories is to use ‘load trade off’. This technique utilises benefits that can occur from a change in building use leading to a lower design load being applied. This is often possible when converting buildings from offices or commercial space to residential use.

Load trade off is not always possible or the client might want to add additional stories that will result in a net increase in load on the structure. In this situation we investigate record drawings and commission specialist testing to calculate the current capacity of the structure. We work through options for what is achievable with the current frame and explore other options such as strengthening solutions to further maximise development potential.

Other common structural issues include changes to the disproportionate collapse class of the building. This requirement of the building regulations is there to ensure buildings are tied together so if one part of the structure is damaged the rest of the building stays standing. Where the lower stories are load-bearing masonry construction, this can require new steel tie rods to be taken down through the structure to the foundations.

In certain situations, adding stories to a building may not be possible where the ground floor is not owned by the client or can’t be accessed for remedial works.