East Herts District Council - The Principles of Conservation & Repair

Historic buildings and conservation areas contribute enormously to the quality of our lives. All of East Hertfordshire's towns and villages are centred on a core of historic buildings, streets, trees and spaces, most of which have been designated as conservation areas. The conservation and enhancement of this heritage is a key objective in planning policy.

It is very important that the principles of the conservation and repair of historic buildings (and structures) in East Hertfordshire are quite clearly stated and fully understood by those thinking about repairs or carrying out works or alterations to any of the listed buildings and structures. There are approximately 4,000 listed buildings and many other interesting unlisted buildings or spaces in the District's 42 conservation areas.

These principles of conservation and repair are useful in making decisions:

to choose suitable approaches and techniques to repair old buildings;

to grant or refuse listed building consent for the extension, change of use, alteration, conversion or even demolition of a listed building;

to agree to contribute towards the cost of repairs by means of an Historic Building Grant;

to grant or refuse planning permission for a new development in a conservation area, or for buildings affecting the setting of a listed building.

What is Conservation?

Historic building conservation can be defined as: the action of protection against undesirable changes and of keeping from harm or decay or loss by sensible maintenance, repair, prudent use, management and stewardship.

It suggests more than just preserving a building, its setting or keeping a whole historic area undisturbed. It calls for active involvement, of doing something to bring about the retention of the quality, beauty and special interest and character of a building or structure - it involves the ongoing repair and it might include adaptation or new use for a building originally conceived for something quite different, or the reintroduction of lost features, such as roofing tiles, windows and doors.

The Society for the Protection of Ancient Buildings (founded in 1877 by William Morris) was very influential in establishing an early basis for conservation of the integrity and character of buildings. It advocated staving off decay by:

"...daily care and the careful repair of buildings to retain as much as possible of the existing fabric and the use of new technology where this could be used sympathetically to help preserve ancient materials."

"We are only trustees for those that come after us."

William Morris wrote in 1889 "... these old buildings do not below to us only ... they belonged to our forefathers and they will belong to our descendants unless we play them false. They are not in any sense our property to do as we like with them. We are only trustees for those that come after us."

A principal aim of conservation is then to ensure that old buildings are not diminished by unsuitable alteration and damaging repair.

Why Conserve Old Buildings And Historic Areas?

The idea of the conservation of buildings and of areas of special architectural or historic interest has only become accepted in the relatively recent past with effective formal legislation only for the last 50 years. Many of the District's 4,000 or so listed buildings were added to the list during the 1980's - others may be included as further resurveys of the District's buildings continue. Conservation areas have been designated only since 1967.

Old buildings by themselves and historic street patterns and spaces between buildings together can create a unique sense of place, harmony and identity and an historic continuity which most people find reassuring and highly pleasing - even inspiring and spiritually uplifting. Continuity, memory and the 'genius loci' - the spirit of the place - are elusive concepts but most people will recognise a sympathy with ancient buildings or even with more recent buildings (such as the red (K6) telephone kiosks) that have become part of the familiar scene and are assimilated into the character of a village or town.

East Hertfordshire's listed buildings are usually attractive buildings, for the most part constructed by craftsmen before the age of mass production. The typical materials in East Hertfordshire used for walling - timber frame (nearly always oak in old buildings) and daub or plaster, soft red bricks, and later yellow stock and gault brick, and flint - and for roofing - red tiles, thatch and later slate are all intrinsically pleasing materials. They can provide a mellowed, aged appearance, surface texture and a patina which cannot be matched in a new building.

The human scale and form of the older buildings, with steeply pitched roofs and generally narrow spans, and the detailing make these buildings distinctive. The spaces around buildings - village greens, narrow lanes, market places or town squares, tightly enclosed urban streets and riverside views - are survivors from before the machine age - and particularly the motor car.

Modern Buildings and Space

Later 20th Century space is often determined by the needs of vehicles - often very large vehicles - which are generally at odds with the human scale, e.g. multistorey car parks, roundabouts, wide roads, dual-carriageways, relief roads, surface car parks, turning heads, on-street car parking, access space for large lorries or fire engines. This can cause feelings of unease and even a sense of alienation.

Dissatisfaction with C20 materials, such as concrete, steel, uniform mass produced bricks, aluminium and plastic, and disillusion with some aspects of modern design seems to have had much to do with an increased respect for and valuing of the quality and richness of past buildings and streets and spaces and a desire to retain the best of this inheritance.

Individually, modern buildings can be exciting, excellent and interesting, however many are perceived as dully, mean, monotonous or ostentatious, vulgar and unrelated to their context, lacking in imagination and of a design determined more by cost and profit rather than any feeling for genuine quality, detail or civic pride.

This does not mean that imaginative and thoughtful modern designs, say for infill sites in conservation areas or even for extensions to listed buildings, will be unacceptable. Such new design must though respect its context and relationship to sensitive and often vulnerable historic buildings and space.

Change

Change is inevitable, nothing stays the same. Most of the listed buildings in East Hertfordshire have survived very many generations, some are many hundreds of years old. None of these old buildings has remained exactly in its original form. All have been repaired, adapted or altered over time. This may be to accord with contemporary fashions, such as refacing a timber framed building in plaster, or giving it a Georgian brick frontage, or replacing thatch with peg tiles or slate. It may be for practical convenience, for example inserting an upper floor and brick chimney stack in a medieval hall, or building a series of additions to provide more accommodation or service areas, heating or other services. Some past alterations point to the historic change and development of buildings. They would use the technologies available at that time. Since the later part of the 19th century and during the 20th century many materials, designs and techniques have come into general use that are far from sympathetic to the intrinsic character of often vulnerable historic buildings. Change has tended to be far more rapid and destructive in recent times than in the past.

New Materials

Materials such as Portland cement have been widely used in mortars and renders; concrete is used for the manufacture of roof tiles, paving slabs, wall blocks and road kerbs; plastics are used for coating windows, for 'glazing bars' and doors and for gutters and drainage pipes.

Other leaflets in this series of Guidance Notes have highlighted the most regrettable changes and unacceptable alterations to windows and doors, brickwork, timber framed buildings, farm buildings in general and the structure and cladding of so many listed buildings and other interesting buildings within and outside conservation areas.

New Alterations

Buildings often need to be thoughtfully altered or extended to adapt to the needs of occupiers and to meet current standards of civilised living. This can be viewed as a means of positive conservation - in that it gives a building a continuing viable use. There is however a balance, which must be carefully struck, to ensure that new extensions, alterations or conversions do not detract from the intrinsic special interest and character of the building.

Conversions of barns to houses and malthouses to new uses have proved that retention of historic character can, impractical terms, be extremely difficult to balance with the hopes of new occupiers.

Unsympathetic Conservation Repairs

It is unfortunately very common to find examples of ill-informed modern alterations and damaging repair:

Old brick or flint walls repointed in a hard a nonporous cement mortar rather than traditional porous lime mortar with coarse sharp sand.
Lime plaster with hair to wood laths, or daub to wood stave or wattle infill panels in timber framed buildings patched, or stripped out,and replaced with expanded metal and cement render, often ''pargetted' with a conjectural surface pattern and painted with modern impervious paint - rather than traditional porous limewash over lime plaster.
Simple indigenous long straw thatch with plaint flush ridges and simple detailing replaced with harsher water reed, or alien combed wheat reed thatch and with over complicated block ridge patterns and fancy gable, hip and eaves details.

Patching or replacement of old peg tile roofs with flat mechanical looking, lifeless, modern machine-made tiles or concrete tiles; or of real slate roofs with substitute artificial 'slates'.
Replacement of cast iron or lead gutters, heads and downpipes with plastic rainwater goods.
New modern 'standard' windows and doors, or even worse UPVC windows or doors, in place of historic patterns and styles. Inappropriate porches or roof extensions and dormer windows.
Unsympathetic alterations to streets and surfaces, e.g. the use of concrete kerbs in place of granite, plastic street name plates instead of cast iron, a plethora of road signs and lights, and the use of precast concrete paving.
'Modernising' the appearance of old buildings by 'scraping' away the evidence of age and removing the impression of 'pleasing decay'.

Beware of over restoration. Every village conservation area and almost every street in the town conservation areas has some examples of these ill-informed alterations or repairs. As well as spoiling the appearance and character of old buildings some of these alterations, such as repointing in cement mortar or cement rendering, are actually very damaging, leading to the accelerated weathering or break down of the surviving historic surface structure or fabric.

A Duty to Respect and Conserve

The Acts governing care and retention of historic buildings place a duty on local authorities to act to prevent deterioration or damage - i.e. buildings in need of repair (Sections 47-59) - as well as having special regard to the needs to preserve a building or its setting or any special features of the building (Section 16(2)).

Once destroyed or irretrievably altered, historic buildings, their details and construction methods and the spaces (and trees) around buildings cannot be recreated. The rate of destructive change is slowing as knowledge and appreciation of our old buildings and surroundings spreads. It is essential, however, that the basic aims of conservation and repair are known to owners and occupiers of historic buildings and by professionals and builders advising or working on listed buildings or in conservation areas.

A Summary Of The Principles Of Repair

Regular Inspection and timely maintenance of buildings - especially roof and rainwater disposal - and repair is essential. (A stitch in time ...)
Minimum gentle and conservative repair only - retaining as much as possible of historic structure and fabric - repair not restoration. Conserve as found. Careful analysis of causes of defects should be carried out and remedied. The aim is maximum survival of historic fabric.
A thorough understanding of the building - will point to an appropriate approach to repair of defects and causes of dampness. Old buildings do not behave in the same away as new buildings. Many builders to not appreciate that a quite different approach is needed - for example in the use of porous lime mortars, renders and plasters, rather than cement based mortars and renders.
When carrying out like-for-like repairs, replacement matching materials should usually very closely match existing to preserve historic integrity and appearance. In some cases the use of different - but compatible - materials can be an honest alternative and still achieve minimal visual intrusion. Reclaimed materials should normally be used for repair only and sympathetic new materials for new buildings.
Proven honest techniques of traditional repair should be used in preference to new methods - unless there is a clear benefit to the building in terms of lessening damage to appearance, historic integrity and fabric. Truth to materials and authenticity.
Repair works may provide an opportunity to resinstate lost elements of a building, such as braces to a timber frame or removed windows, doors, cast iron or lead rainwater goods etc. Speculative reconstruction or alteration is unacceptable. Evidence should exist to allow accurate replacement.
Every intervention should, wherever possible, be reversible. An historic element of a building, once destroyed, can never again be called into evidence.
Repairs to historic buildings should only be undertaken and supervised by those with appropriate expertise, craftsmanship, respect, skills and appreciation of history and beauty and commitment to the fundamental principles of conservation. Many builders (and some professional advisers) do not have the necessary skills, expertise or knowledge. When seeking estimates or tenders for work a properly detailed specification and schedule of works should be provided by an experienced conservation architect, surveyor or other suitably skilled adviser.

Bibliography

Planning(Listed Buildings and Conservation Areas) Act 1990

Department of the Environment and Department of National Heritage
Planning Policy Guidance Note 15:
Planning and the Historic Environment (September 1994)

English Heritage
'The Repair of Historic Buildings - Advice on principles and methods' Christopher Brereton 1991
(English Heritage - 23 Savile Row, London W1X 1AB, Tel 0171-973-3000)

The Society for the Protection of Ancient Buildings, manifesto and series of technical leaflets and advice notes.
(37 Spital Square, London E1 6DY, Tel 0171-377-1644)

The Georgian Group Guides
(6 Fitzroy Square, London W1 6DX, Tel 0171-387-1720)

The Victorian Society Guides
(1 Priory Gardens, Bedford Park, London W4 1TT, Tel 0181-994-1019)

The Twentieth Century Society
The Philosophy of Twentieth Century Conservation
(70 Cowcross Street, London EC1M 6BP, Tel 0171-250-3857)

Since 1975 the District Council has encouraged and contributed to the cost of sympathetic repairs by means of Historic Building Grants.

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The Principles of Conservation & Repair

Introduction