Ways to Ruin an Old Building
1 Employ consultants and contractors who do not specialise in historic
importance of old buildings is not in question. Historic town and
city centres across the British Isles attract millions of visitors
every year, and houses within areas that contain few post-war alterations
command significantly higher values than similar houses in areas
which are broken up by modern developments. Their appeal lies not
only in their sense of history but also in their visual character
and interest: the rich variety of colour, texture and form, the
individuality of natural and hand-made components, the abundance
of intricate details from fine glazing bars to decorative railings
and street furniture, and the softness of mature landscaping.
redevelopment which damaged so many historic centres, particularly
in the 1960s and ‘70s, almost all our towns and cities retain pre-20th
century historic cores, and around one in five buildings today pre-dates
1914. In those urban centres where historic integrity is strong,
the character is maintained not only by planning control but also
by peer-pressure and increasing recognition that insensitive alterations
will damage the financial value of the owners’ properties. However
far more old buildings have been hidden under a veil of alterations,
and in many cases poor alterations and a lack of maintenance threatens
redevelopment in historic centres is rare, and the greatest threat
comes from the small, insidious ‘improvements’ often made by well
intentioned but misinformed owners, their contractors and consultants,
as well as from a lack of regular maintenance. Traditionally constructed
buildings do not perform in the same way as modern ones and need
to be treated differently, at every stage of their conservation
and repair. Modern materials and construction techniques are often
incompatible with traditional ones, and repairs which are suitable
for modern buildings can lead to the deterioration of historic building
fabric. Relatively few contractors and consultants have the expertise
required to deal with the special problems of historic buildings,
and even relatively harmless techniques can damage historic materials
in the wrong hands.
|A few simple alterations have made one half of this attractive Victorian
house look modern, and the loss of the garden and its front wall have
added to the erosion of a conservation area (Kit Wedd)
2 Do not carry out any essential maintenance work
- If huge repair
bills are to be avoided and important historic fabric protected,
owners need to clear gutters of leaves in the autumn; roofing
slates and tiles need to be replaced, flashings maintained and
chimneys pointed and capped to prevent water entering the fabric
of the building, causing decay.
- Air bricks and vents need to be kept clear of weeds to ensure that cellars
and sub-floor cavities are kept well ventilated to prevent condensation,
which also causes decay.
- Pipes, washing machines, shower trays and other potential sources of water within
the building need to be checked for leaks for the same reason.
signs of decay caused by poor maintenance
3 Use cement in place of lime for mortars
which is traditionally constructed is bedded in soft lime mortar
and is relatively flexible: pointing with a hard cement restricts
its movement, causing stress in the surface of the wall where
it is bound by the cement, and the face of soft stone and brick
will fail as a result.
- Cement mortars
are also impermeable - that is to say that they do not allow the
structure behind to 'breathe': moisture is forced to evaporate
through the stone or brick, and in extreme cases may cause these
materials to deteriorate.
mortars may also be visibly different, both in colour and detail:
being hard they can be made to project forward from the face of
the wall, or may be smeared across the edges of stones, changing
the appearance of the wall as a whole.
timber framed house with panels re-rendered using a hard cement; the
panels allow rain to penetrate the walls at their junction with the
exposed timbers but the hard render restricts its evaporation, causing
extensive decay (Robert Demaus)
Paint or coat surfaces which were originally left natural
coatings and most modern paints and stone consolidants are not
porous and will lock moisture in the walls: evaporation is concentrated
at cracks where any salts present crystallise, causing decay.
- Damp patches
may appear on the inside wall as more moisture is forced to evaporate
materials will deteriorate rapidly as a result of the increased
moisture levels, including cob, daub and other earth mixtures,
and timber is more likely to rot.
- All non-original
coatings hide the original colour and pattern of stone and brickwork
and modern coatings and claddings such as stone cladding, pebble-dashing,
and other modern cementitious coatings make old buildings look
(at best) modern and ordinary.
of moisture from a wall is concentrated by an impermeable coating
at cracks, leading to localised stone decay due to salt crystallisation.
The use of colour to emphasise the drain pipe is also questionable
Extend or alter the accommodation in a manner which conflicts with
- Badly designed
extensions can dominate the existing building by virtue of their
size or style, or a change in material or finish.
alterations which involve the loss of the original layout of rooms,
decorative features or principal features such as fireplaces and
staircases damage the character of the interior.
the garden with tarmac to create forecourt parking damages the
townscape and the setting of a building.
early 18th century cottage with dressed stone windows has been altered
and extended many times this century, most recently with the top-heavy
dormer windows and the porch (see next illustration)
Introduce mix-and-match ‘period style’ detail
- The addition
of reproduction features for uses never originally intended, such
as 'carriage lamps' on either side of a front door, external shutters
particularly where they are fixed to the walls and clearly serve
no functional purpose, and ‘bulls-eye’ glass panes make old buildings
look cheap and phoney.
- Poor 'period-style'
features such as front doors with press-moulded panel mouldings,
black rubber seals, fanlights within the door itself, stuck-on
strips in imitation of leaded lights, and other fancy details
look incongruous in a genuinely historic building.
- The ‘restoration’
of features where they never existed confuses the history of a
building; for example, the introduction of fine plaster mouldings
in attic rooms, basements and other rooms where features were
once simple and functional.
details have been chosen to look 'quaint’, but would be more in keeping
with the character of a modern housing estate than this 18th century
Replace original components unnecessarily
windows are rarely necessary: decay is usually limited to the
bottom few inches of the frame and new timber windows are liable
to decay more quickly than the originals would if repaired.
- The removal
of all timber within one metre of any visible sign of dry rot
(which is still advocated by many) is excessively devastating
and unnecessary as the reintroduction of dry, ventilated conditions
alone will prevent its growth.
- Old and
original structures which have distorted through old settlement
and are now stable may need repair, but rarely need to be replaced.
plastic windows in particular (see 6 & 7 above) fail to
match the appearance of old windows: they invariably have larger,
heavier sections than timber windows; black rubber gaskets are
visible around the glass; and fine glazing bars cannot be incorporated
convincingly. Their claim to be 'maintenance-free' is also misleading
as plastic, like paint, becomes scratched and disfigured by
dirt in time, and it will eventually need to be painted regularly
to maintain its appearance.
plastic windows in particular detract from the character of old buildings
Position modern services and equipment intrusively
dishes, air-conditioning units and extractor fans are alien features,
which, where necessary, can usually be positioned discreetly.
wires, telephone cables, lightning conductors and other services
need to be installed tidily without snaking across walls and decorative
features; careful planning may avoid the need to chase service
runs into the original structure.
- Modern fixtures
such as radiators, smoke detectors and other interior service
fittings can be painted to blend with the prevailing colour of
the wall to which they are fixed, and in some cases may be hidden
altogether without affecting their performance.
dishes need to point in a particular direction, but they do not need
to be on the front of a house, nor do they need to be coloured black
Use cleaning methods which damage original surfaces
and even the most gentle air abrasive cleaning can remove the
surface from stone or brick, particularly in the wrong hands and
should never be used on timber.
cleaning agents such as acids and alkalis react with stone and
brick as well as dirt layers, causing damage, and all can leave
harmful residues behind
- Water even
under low pressure soaks masonry and can cause surface staining
and efflorescence (salt crystallisation), and in the worst cases
may lead to the decay of masonry.
- Paint-stripping doors by immersion in a caustic bath damages wood and removes glue from joints.
in a bath of caustic soda is by far the cheapest way to paint-strip
doors, but also the most damaging to the timber and the joints in
Overload an existing structure
slates with concrete roofing tiles can cause rafters to bow and
even collapse under the increased weight unless the structure
part of a building can move loads onto other parts of the structure,
exacerbating settlement damage, and is often carried out unnecessarily.
low ties of a roof truss (the horizontal beams which run at eye-level
across the attic, at right angles to the ridge) can cause the
roof to spread and collapse.
chimney breasts, walls and other structural features can also
damage the structural integrity of the building.
tie beams literally tie the two sides of the roof together. Their
removal to make an attic usable can lead to the collapse of the roof
(the location of the tie beams removed in the past is indicated by
the dotted lines)
Taken out of
context, this long list of don'ts would no doubt cement many people’s
view that conservation is all about freezing buildings and places
in a perpetual time warp at the expense of any function. However,
conservation encompasses a broad range of measures and approaches
to historic buildings, and at its best conservation is an extremely
Within the field
of building conservation, the term 'conservation' may be defined as
the process of protecting a building and its surroundings from any
change that might involve a loss of historic fabric, historic importance
or character. This process is made more complex by the fact that most
buildings have an active function, and the need to accommodate the
function is a recognised facet of building conservation.
needs to be made between conservation, preservation and restoration,
which are often erroneously used to mean the same thing. In the field
of building conservation the term 'preservation' is generally used
to distinguish a particular type of conservation work sometimes referred
to as ‘conservation as found’, in which the fabric is preserved in
the state in which it was at the start of the project. Conservation,
on the other hand, may involve an element of alteration, for example;
to maintain the functional use of the building, or to prevent its
another term used erroneously to mean conservation. Here the issues
are more complex, since some restoration work may involve stripping
away historic alterations to reveal earlier fabric, and in most restoration
work new material is introduced to match missing components. In this
respect the aim of restoration is clearly different from that of conservation,
and some restoration work may actually damage the historic character
of the building. Nevertheless, most conservation work involves some
element of restoration, particularly where essential repairs are carried
out to match the original form of a decayed component, where the aim
is primarily to conserve fabric.
does not mean freezing a building in its present state for perpetuity,
it does mean that all alterations must be carefully justified beforehand,
taking into account not only the affect of the works in the short
term but also their consequences for the building, its character,
historic interest and its functionality in the future. Historic
architecture can often be adapted to meet modern requirements without
loosing any historic fabric or with alterations which are designed
to be 'reversible'. Where buildings which are listed or in conservation
areas are concerned, the degree of alteration permitted by local authorities
will vary according to the importance of the building and the components
affected and how essential the alteration is to the function of the
caring approach to old buildings is essential to the whole community.
Historic architecture affects us all, whether we live in an old building
or neighbourhood, shop in historic urban centres, or enjoy sightseeing.
Neglect, decay and insensitive alteration has a real impact on the
quality of our surroundings.
article is reproduced from The Building Conservation Directory, 1998
JONATHAN TAYLOR is the editor of The Building Conservation Directory and a co-founder of Cathedral Communications Limited. He studied architectural conservation at Heriot-Watt University, Edinburgh and has a background in architectural design, conservation and urban regeneration.
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