Informed conservation: principles and practice
Setting out knowledge about buildings and places in a systematic way makes it possible to
make informed and appropriate decisions about proposals for change.
  112 Colmore Row, Birmingham in 1956
(left) and 1999 (right) Now English Heritage’s West Midlands regional office, 112 Colmore Row has been subject to significant changes that have taken place to the ground floor façade over the past 40 years. Both photographs were rectified to remove distortion and allow the development of new proposals for the ground floor façade.

Colmore Row (1956) © Birmingham
City Council Planning Department
Colmore Row (1999) © Jim Gard’ner,
English Heritage

  ‘Every single application which has been seen by [English Heritage’s] Urban Panel has suffered from an inadequate understanding of the context and significance of the place,’ said Martin Cherry, chief buildings historian of English Heritage, recently. His view is typical of many of those who deal with proposals to develop or change elements of the historic environment. It is reiterated in findings that local planning authority officers consider only approximately half of applications submitted for listed building consent of adequate quality 1.

Informed conservation puts at its heart a clear understanding of what is important about a site and why – a philosophy it shares with the conservation planning process. Without this understanding of a site and its context, it is not possible to make informed and appropriate decisions about proposals for change.

Building owners and developers are often driven by user-needs or financial considerations, and will understandably invest significant emotion in proposals. Their desire to make changes to their heritage asset is therefore often not matched by an understanding of the history and development of the property, or the value which might be placed on it by the wider community or those with a special interest in the historic environment. Informed conservation offers local and central government agencies a mechanism to encourage a thorough understanding of the site to be developed, going beyond the statutory designation and list description. Its application within the planning process will facilitate a more informed decision making process by the local planning authority, and will hopefully broaden the site owners’ understanding and appreciation of the special importance of their historic property.

A thorough understanding of a historic building or monument is necessary to be able to undertake its repair or restoration within the principles established by the Venice Charter. The Australian Burra Charter, first published in 1979, builds upon the Venice Charter by placing understanding at the heard of conservation. Article 6 of the later charter states that ‘the cultural significance of a place… [is] best understood by a sequence of collecting and analysing information before making decisions.’ 2 Internationally the principles behind informed conservation have been adopted in New Zealand (through the ICOMOS New Zealand Charter), in the Canadian concept of ‘commemorative integrity’, and within World Heritage Site management plans. The central tenet of informed conservation, that of understanding the place prior to management decisions being taken, is expounded within the context of the conservation planning in James Semple Kerr’s definitive guidance on the subject, The Conservation Plan 3.

The English planning system enshrines the need for the applicant or developer to provide full information and appropriate understanding through PPG15 Planning and the Historic Environment 4 and PPG16 Archaeology and Planning 5. This planning policy guidance is endorsed by English Heritage advice such as Development in the Historic Environment 6 and Guidance Notes for Applicants 7.


Informed Conservation is available for £10 from English Heritage Postal Sales, Gillards, Trident Works, Marsh Lane,
Temple Cloud, Bristol
BS39 5AZ (tel 01761 452966 or fax 01761452966); product code

The latest edition of The Conservation Plan by James Semple Kerr is available for £12.50 from
ICOMOS UK, 10 Barley Mow Passage, London W4 4PH (tel 020 89946477 or fax 020

The provisions included within English planning policy guidance PPG16 covering the need for early evaluation of archaeological deposits effected by development proposals have been successfully applied to a greater or lesser degree. Although PPG15 contains many similar provisions to PPG16, it arguably has been less rigorously applied to work impacting on the built historic environment. The desire to fill this gap between the general policies of PPG15 and the very specific guidance contained within its Annex C was behind a recent English Heritage publication, Informed Conservation 8.

This guidance sought to bring the diverse disciplines and a wide range of techniques applied to the understanding of buildings into a single concept of ‘conservation-based research and analysis’ (or CoBRA), which its author Kate Clark defined as ‘the research, analysis, survey and investigation necessary to understand the significance of a building and its landscape, and thus inform decisions about repair, alteration, use and management’.

Another aim of this initiative is to encourage the breaking down of barriers that continue to exist between professional disciplines involved in the understanding and conservation of historic buildings, to ensure that a full range of skills and knowledge is brought to bear on a site. Likewise the establishment of a common language should enable better communication between archaeologists, architects, planners and other specialists, and help ensure that the most appropriate research is undertaken and information gathered.

The critical issue for many applicants will be the time and cost implications of what they may perceive as additional requirements and bureaucracy. The type and quantity of information requested by the local planning authority must be proportional to the scale of the development or proposals for change, as well as to the nature of the site itself. Different levels of information may be required at different stages of the consent process, and what is appropriate information for one site or development may not be for another.

The range of research and analytical techniques that can be applied to the historic environment are many-fold, from documentary research such as map regression and the use of historic images, through to specialist scientific techniques such as architectural paint research, mortar analysis, dendrochronology, geophysics and remote sensing. Drawn surveys are also a vital tool for the understanding of a structure and its development.

These can vary in their sophistication from simple hand sketches at an approximate scale to highly dimensionally accurate 3-D photogrammetry and CAD drawings. A variety of analytical techniques can flow from the survey drawings and other analysis, including phasing analysis, numbering and typology studies of specific elements or materials. These and other techniques for understanding buildings and their context are described in Informed Conservation.

An impact assessment can be undertaken to determine whether or not a proposal for change puts the special interest or significance of a historic building or site at risk. Informal assessments of the impact of proposals are undertaken everyday, whether preparing design proposals for a major new development or assessing an application for a domestic extension. However, this process is seldom recorded in a clear way that can be audited.

Through a formalised impact assessment process the following questions should be asked to test a proposal for change: what is the need and justification for the work; what is the special interest or significance  of the site; what is the impact of the proposal on the special interest or significance of the site; can further information help in understanding the site; can any negative effects be mitigated?

A decision can then be taken to accept or reject the proposals, to request further specific information, to request changes to the proposals, or to impose conditions that mitigate the negative impact of the scheme. These questions can form headings within  a heritage impact assessment table to record the decision-making process as well as the decision itself.

Where current proposals are unsatisfactory in heritage terms, mitigation (or designing-out negative impacts) should be employed. All too often, in the  past, recording of what was going to be lost was seen as adequate mitigation. It was commonplace for this recording to identify previously unknown aspects of the site’s importance or significance at too late a stage in the planning process.

Options which applicants and their professional advisers may consider to help minimise adverse impact on the historic place include: reassessing the need  for the work; finding an alternative local or site; redesigning proposals or selecting different materials; re-timing or reprogramming works; finding alternative ways of meeting the need.

The benefits of improved information and understanding of a site or building are wide ranging, from improving the applicant’s understanding of the historical development and importance of their property to improving the  information on which architects and other building professionals will base their proposals for change. However, most importantly, as a report by the Oxford Brookes University school of planning (September 2000) concludes, the provision of better information at the outset can improve both the quality and speed of the decision-making process.

These benefits accord with aims of many of the ‘best value’ exercises local authorities are undertaking. As well as informing development proposals  and aiding the statutory decision-making process, the results of the research and analysis can and should also be fed into the conservation plan for a site or published in another accessible form.

Informed conservation offers a framework and methodology to help ensure that decisions about change within the historic environment are made  based upon full information, gained through an appropriate level of research and analysis. ‘Ultimately,’ as the introductory summary of Informed Conservation concludes, ‘all conservation depends on a clear understanding of what matters and why.’

1 Grover P, Thomas M & Smith P, Local Authority Practice and PPG15: Information and Effectiveness, Oxford Brooks University School of Planning, September 2000 [report commissioned by English Heritage, IHBC and Association of Local Government Archaeological Officers]
2 The Australia ICOMOS Charter for Places of Cultural Significance (The Burra Charter), Article 6.1, 1999.
3 Kerr JS, The Fifth Edition Conservation Plan: a guide to the preparation of conservation plans for places of European cultural significance, National Trust of Australia (NSW), Sydney, 2000
4 Paragraph 3.4, Planning Policy Guidance: planning and the historic environment (PPG15), DoE/DNH, 1994.
5 Paragraph 21, Planning Policy Guidance: Archaeology and Planning (PPG16), DoE/DNH, 1990.
6 English Heritage, 1995
7 English Heritage, 2000
8 Clark K, Informed Conservation: Understanding historic buildings and their landscapes for conservation, English Heritage, London, 2001


Jim Gard’ner works for the south east region of English Heritage as the historic buildings architect responsible for the counties of Berkshire, Buckinghamshire and Oxfordshire.