42 Bedford Square

Refurbishment of two Grade 1 listed Georgian buildings

42 Bedford Square was originally constructed in the Georgian era circa 1770 and, as with most Georgian buildings, considerable attention was given to the finishes but less to the structural integrity of the building. Walsh was approached to help convert the building back from its latest use as poor-quality office space to prime residential.

Our investigations revealed that the building that had been very poorly maintained in the past. The main problems discovered during our investigations were:

• The main spine beams had deflected considerably due to timber creep and were generally undersized for the use to which they were put to in the present day.
• The front wall was separating from the main structure and was in danger of collapse.
• The structural strength did not comply with present day standards and all the spine timbers needed to be strengthened.
• Considerable cracks existed in the stone stairs due to the removal of sections of handrail and general abuse.
• Considerable cracks were evident throughout the brickwork.
• The drainage was insufficient and needed to be totally re-laid throughout.

Our remedial designs, done under the watchful eyes of architect BDP Heritage Department and English Heritage, comprised of:

• Beam strengthening by plating spliced steel plating of existing beams to support the new loadings.
• Due to local subsidence and the incorporation of a new lift it was necessary to carry out local underpinning and foundation strengthening.
• Due to loose, separating brickwork on the front elevation, it was necessary to pin back the front façade along with replacing sections of brick which could not be saved.
• Repair and strengthening of existing stone torsion stair (this is often incorrectly called cantilever stairs) by the insertion of resigned bars to pin steps together along with similar action on the landings.

We had the additional challenge that our client wished to end up with a building with state-of-the-art services. These services included modern plumbing along with air conditioning and other services. This entailed notching existing undersized spine beams and the design of bespoke strengthening solutions throughout the building.