Conservation Principles, Policies and Guidance - English Heritage
Conservation Principles, Policies and Guidance - English Heritage
Conservation Principles, Policies and Guidance - English Heritage
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ENGLISH HERITAGE CONSERVATION POLICIES AND GUIDANCE<br />
119 The use of materials or techniques with a lifespan that is predictable from<br />
past performance, <strong>and</strong> which are close matches for those being repaired<br />
or replaced, tends to carry a low risk of future harm or premature failure.<br />
By contrast, the longer term effects of using materials or techniques that<br />
are innovative <strong>and</strong> relatively untested are much less certain. Not all historic<br />
building materials or techniques were durable – iron cramps in masonry,<br />
or un-galvanised steel windows, for example, are both subject to corrosion.<br />
Some structural failures are the inevitable, if slowly developing, consequences<br />
of the original method of construction. Once failure occurs, stabilising the<br />
structure depends on addressing the underlying causes of the problem,<br />
not perpetuating inherent faults.<br />
120 The use of original materials <strong>and</strong> techniques for repair can sometimes destroy<br />
more of the original fabric, <strong>and</strong> any decoration it carries, than the introduction<br />
of reinforcing or superficially protective modern materials. These may offer<br />
the optimum conservation solution if they allow more significant original fabric<br />
to be retained. In historic l<strong>and</strong>scapes, planting may need to utilise alternative<br />
species, to resist disease or the effects of climate change. Before making<br />
decisions, it is essential to underst<strong>and</strong> all the heritage values of the elements<br />
concerned, <strong>and</strong> to consider the longer term, as well as the immediate,<br />
conservation objectives.<br />
121 Sometimes, the action necessary to sustain or reinforce one heritage value can<br />
be incompatible with the actions necessary to sustain others. Underst<strong>and</strong>ing<br />
the range, inter-relationships <strong>and</strong> relative importance of the heritage values<br />
associated with a place should establish priorities for reconciling or balancing<br />
such tensions. While every reasonable effort should be made to avoid or<br />
minimise potential conflict, contrived solutions requiring intensive maintenance<br />
are likely to be difficult to sustain.<br />
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