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The majority of listed buildings must be used to survive, just as the majority of conservation areas must develop to survive economically and socially. There is no avoiding the fundamental conflict between necessary change, to meet current and future needs, and preservation. Architects and Conservation Officers wifi always be challenged to find new and better ways to minimise this conflict. This should be a creative opportunity rather than a chore. I have recently been responsible for refurbishing and altering an 18th century stable building, within the curtilage of a Grade 2* listed building in Kent, a former vicarage. The ground floor of the building had, within the last century, been converted to a garage, the picture of the Vicarvisiting his parishioners on horseback or in horse and carriage being lost forever. The hayloft above was used, or rather neglected, as a store. To enable the leap to be made between the very large cost of refurbishment and any discernible gain, some amenity had to be added to the property.
Sevenoaks District Council is responsible for Westerham Conservation Area, within which this building lies. Mike Higgins is the Conservation Officer there. English Heritage was consulted and proposals were referred to The Secretary of State for the Environment.
The building was in a state of near collapse. The roof had spread, 600mm at the eaves at one end, taking the side walls with it. The gable walls and the roof had parted company. The truss, supporting the purlins centrally, clearly never up to the job, had deflected massively. The ends of the purlins built into the gable walls had vanished, presumably rotted and then cut off at some stage.
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The original hay loft had to be made usable to justifythe cost ofrefurbishment. Ideasinvolvingthe addition ofnewtimber trusses, and of reinforced concrete beams at the eaves with ties between them, were passed over. They either conflicted visually with the existing structure. or cut across the space and door openings.
The agreed solutionwas afine stainless steel cable and a stay to each rafter, with a plywood skin to the upper face of the rafters. This method changes the structural system of the roof.
The original rafters were effectively articulated, being of two short sections tenoned and pegged into the purlins. The cables and stays allow the rafters to spanfrom eaves to ridge, thus making the defective central truss redundant, and alleviatingthe need to support the purlins at the gables. The rafter pairs are tied together, to prevent spreading, with an additional stainless steel cable. The cables were tensioned, and then re-tensioned whentheloadofthe rooftileswas applied.
The plywood skin has two functions. It counteracts the tension in the cables in the event of wind uplift removing the load of the tiles. It also provides wind bracing to the roof and sufficient rigidity to restrain the gable waIls, which are now tied to the roof. The picturesque charm of the original roof structure has been affected as little a possible. The space is usable.
The cost of this work to the roof structure, around £4,500, is considerably less than that of complete restoration, i.e. dismantling, replacing defective or missing members and reassembling. The use of the space would have been very restricted if the original structural system had been retained and the gable walls
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would have remained unsupported. It must also be borne in mind that, even prior to decay, the structure was unable to sustain the load applied to it.
The system. with some adaptation, might have been used to re-support the splaying chancel roof ofAll Saints Church in Langport, Somerset. However, this church has now been closed and is, I understand, up for sale for the sum of £1. In brief, the story was that there were two reports carried out. One suggested that there was over £50,000 of work to be carried out, the other estimated it at over £500,000. The worst scenario was adopted and the church had to close.
It is unrealistic to see the conservation of historic buildings as one large, finite task. To fully restore is just to restart the cycle of decay. Conservation is more akin to the cabaret act of keeping a large number plates spinning on top of sticks. It is only right and often necessary to give one plate just a passing tweak, so thatyou may concentrate on another that is about to crash to the ground!
With the limited resources available for the task, Conservation Officers, heritage bodies, architects, and building owners (sources of funding remember!) must work together. This must be done with care,with imagination, and in as fluid a manner as possible. New uses for buildings, newways to sustain life within conservation areas, and new ways to conserve their fabric must be sought. Conservation Officers should be in a better position than most to provide a broad and strategic view.
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AlastairBinnie is the Principal of Alastair Binnie
Architectural Design & Metalwork,
Stanton
Harcourt.
Oxfordshire.
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CONTEXT 45
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23
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