Suspended Mezzanine in Living Space
The project is the refurbishment of a double height living space in North London. The main element of this refurbishment is the replacement of a mezzanine level which provides sleeping and a study area.
The original mezzanine which was much smaller, sat in one corner of the main space; this was supported from below on a network of standard steel sections which occupied more space than the mezzanine generated. The brief therefore was to create as large as possible new mezzanine with minimal physical impact on the space below. To enable enough headroom for the new mezzanine, large area of the existing ceiling was removed to reveal the previously isolated space defined by the pitched roof.
The intention was that any new structure would be integral to the overall fabric and composition, rather than the structure simply supporting the architecture. The key component here is the balustrade, this is required to be solid to give privacy to the sleeping space and it also provides the primary support for the mezzanine structure in the form of a very thin deep beam. The lightweight properties of plywood allowed us to hang the inside corner of the balustrade beam from the existing roof timber structure above which is strengthened with additional timbers to take new loads. The balustrade is formed from three layers of 12mm Finnish birch plywood laminated together. The middle layer is offset by half its length effectively forming a huge mortice and tenon joint all of which was fabricated on site. Standard timber joists are end fixed to the balustrade beam using 5 x 70mm wood screws through the face of the plywood which is then plugged. The varnishes plywood floor to the mezzanine is back fixed from below and contributes to the overall bracing of the structure.
Access to the mezzanine is via a steel folded plate staircase which is treated as completely separate and only touches the mezzanine once at the extreme end of one of its handrails.
Structural EngineerWebb Yates Engineers
Wood SupplierJames Latham
SpeciesFinnish birch-faced plywood and ash