IStructE Structural Award 2016 – 65 Quay Street, Orford

 

J P Chick & Partners have pleasure in announcing that David Cantrill based in the Norwich office has received a commendation for the structural engineering design of the repair, refurbishment and extension to 65 Quay Street. The IStructE structural award 2016 – 65 Quay Street, Orford was presented by the East Anglian Regional Group for ‘Structural Excellence’.

This grade II listed residential dwelling is located in the delightful tourist spot of Orford on the Suffolk Heritage Coast.  65 Quay Street is an 18th century cottage with a history of alteration and refurbishment, some of which had affected its structural stability.  

The Details

Originally constructed as a timber frame, the cottage was then enclosed within a brick skin, which had been poorly tied to the original structure.  During subsequent alterations over the years, tie beams at roof level had been cut through to facilitate movement between rooms.  This had led to roof and wall distortion.  The one and half storeys complicated the issue, with limited head room.  Therefore a discreet framing arrangement was necessary to permit the flow of forces from the roof through the truncated tie beams, and down to the floor structure.  The design of a system of steel dowel rods and hidden steel plates was drawn up.  

The extensive decay in many of the key timber elements did not become apparent until the contractor started on site. The structural challenge was to ensure that repairs could be undertaken insitu and that they and the existing undersized beams were sufficient to transfer the necessary forces.  Careful consideration had to be given to the decayed timber removal and installation of the steel plates and dowel rods to ensure that they could reduce material wastage and ensure the heritage value of the structure was not compromised.

The Clients planned a spacious highly contemporary extension to the rear of the property.  This extension is predominately of lightweight construction with a glazed rearward elevation with two flanking walls one brick and block work the other being timber frame.  The timber frame being clad in vertical larch cladding terminating in a curved pier feature. 

Historical distortions and shallow foundations made marrying the extension with the historic structure challenging. The solution required a network of very shallow steel channel sections to provide a framework to accommodate the roof joists and a significant central glazed roof light within it. The steel framework is independently supported with all loading carried on the new construction. The verticality of the existing structure proved a challenge during setting out.

Overall this project brought structural challenges which were overcome.  The resulting contemporary extension design married light elegant construction to historic fabric for future generations.

Architect:  Gorniak & McKechnie

Principal Contractor:  ESH Elliston Steady & Hawes