Overview

This project involved the structural transformation of an existing barn into a high-specification residential dwelling. The primary objective was to maximise the internal volume to accommodate a substantial two-storey section while maintaining the building's distinctive barrel-vaulted profile.

The challenge

The primary constraint was internal clearance. To achieve a functional second floor within the existing building envelope, the roof structure had to be incredibly slender. Traditional timber rafters or deep trusses would have consumed too much vertical space, making the upper floor unviable. We needed a structural solution that provided high-load capacity with a minimal vertical footprint.

The structural strategy

To solve the head-height challenge, we engineered a hybrid internal structure. We utilised bespoke curved steel members to create a barrel-vaulted portal frame. This allowed us to follow the roof's radius with a slim profile, successfully maintaining the required clearance for a two-storey layout. Between these primary steel frames, we designed 'stick-built' timber infill panels, providing a high-performance thermal skin. Unlike more complex sites requiring suspended floors, the favorable ground conditions allowed for the use of traditional strip foundations and a ground-bearing floor slab, providing a robust and cost-effective base for the new internal structure.

Outcome

The result is a conversion that maximises every cubic inch of available space. By using a hybrid steel-and-timber strategy and a pragmatic approach to the sub-structure, we provided the client with an expansive two-storey home that balances architectural ambition with structural efficiency.