0750658630.Architectural.Press.Conservation.Of.Historic.Buildings
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Conservation of Historic Buildings Frontispiece Ospizio di San Michele, Rome, Italy, before conservation This state of affairs was due to lack of maintenance resulting from planning blight. The rainwater outlets were allowed to become blocked, so the gutters overflowed causing rot in the ends of the main beams which in due course collapsed taking the roof structure with them Conservation of Historic Buildings Third edition Bernard M. Feilden Kt, CBE, D Univ, D Litt, FSA, FRSA, AA Dipl(Hons), FRIBA Director Emeritus, International Centre for the Study of the Preservation and the Restoration of Cultural Property (ICCROM), Rome Architectural Press AMSTERDAM BOSTON HEIDELBERG LONDON NEW YORK OXFORD PARIS SAN DIEGO SAN FRANCISCO SINGAPORE SYDNEY TOKYO Architectural Press An imprint of Elsevier Linacre House, Jordan Hill, Oxford OX2 8DP 200 Wheeler Road, Burlington, MA 01803 First published 1982 Revised paperback edition 1994 Third edition 2003 Copyright © Elsevier 1994, 2003. All rights reserved No part of this publication may be reproduced in any material form (including photocopying or storing in any medium by electronic means and whether or not transiently or incidentally to some other use of this publication) without the written permission of the copyright holder except in accordance with the provisions of the Copyright, Designs and Patents Act 1988 or under the terms of a licence issued by the Copyright Licensing Agency Ltd, 90 Tottenham Court Road, London, England W1T 4LP. Applications for the copyright holder’s written permission to reproduce any part of this publication should be addressed to the publishers Permissions may be sought directly from Elsevier’s Science and Technology Rights Department in Oxford, UK: phone: (ϩ44) (0) 1865 843830; fax: (ϩ44) (0) 1865 853333; e-mail: [email protected]. You may also complete your request on-line via the Elsevier homepage (http://www.elsevier.com), by selecting ‘Customer Support’ and then ‘Obtaining Permissions’. British Library Cataloguing in Publication Data Feilden, Bernard M. Conservation of Historic Buildings. – New ed I. Title 363.69 ISBN 0 7506 5863 0 For information on all Butterworth-Heinemann Publications, visit our website at www.bh.com Typeset by Newgen Imaging Systems (P) Ltd., Chennai, India Printed in Great Britain Contents Preface to third edition vii Acknowledgements xiii 1 Introduction to architectural conservation 1 Part I Structural Aspects of Historic Buildings 2 Structural actions of historic buildings 25 3 Structural elements I: Beams, arches, vaults and domes 37 4 Structural elements II: Trusses and frames 51 5 Structural elements III: Walls, piers and columns 61 6 Structural elements IV: Foundations 79 Part II Causes of Decay in Materials and Structure 7 Climatic causes of decay 93 8 Historic buildings in seismic zones 119 9 Botanical, biological and microbiological causes of decay 133 10 Insects and other pests as causes of decay 139 11 Man-made causes of decay 157 12 Internal environment of historic buildings 173 Part III The Work of the Conservation Architect 13 Multi-disciplinary collaboration projects in the UK 189 14 Inspections and reports 203 15 Research, analysis and recording 221 16 Preventive maintenance of historic buildings 235 17 Fire 251 18 Presentation of historic buildings 261 19 Cost control of conservation projects 273 20 Rehabilitation of historic buildings 277 v Contents 21 Special techniques of repair and structural consolidation 295 22 Conservation of modern buildings 327 Appendix I Historic buildings as structures by R.J. Mainstone 337 Appendix II Security in historic buildings 347 Appendix III Non-destructive survey techniques 353 Appendix IV Manifesto for the Society for the Protection of Ancient Buildings 359 Appendix V ICOMOS Charters 361 Bibliography 369 Index to buildings, persons and places 381 Subject index 383 vi Preface to third edition ‘It is important to understand why we are drawn The building conservation team should observe to a good building of any age. First there is the certain ethics: intellectual achievement of creating an artefact of beauty and interest. Second, the human 1. the condition of the building must be fully achievement perceived by later generations in recorded before any intervention is begun; the care of the craftsmen in its construction. 2. the materials and methods used during treatment This care can also be visible in later repairs and must be documented; alterations. Thirdly, we are drawn by the sense 3. historic evidence must not be destroyed, falsified of place created both by the designers and or removed; many humans who have lived and worked in 4. any intervention must be the minimum necessary. the building.’ It should be reversible—or at least repeatable, Alan Baxter—Journal of Architectural and not prejudice possible future interventions; Conservation, no. 2, July 2001 5. any intervention must be governed by unswerv- ing respect for the aesthetic, historical and phys- Basically, all conservation consists of actions taken ical integrity of cultural property. to prevent decay, and within this objective it also includes management of change and presentation These are stringent guidelines. Interventions must of the object so that the objects’ messages are made not hinder later access to all the evidence incorpo- comprehensible without distortion. Architectural rated in the building, and allow the maximum conservation is more complex; first because a amount of existing material to be retained. They building must continue to stand up; secondly, eco- must also be harmonious in colour, tone and tex- nomic factors usually dictate that it should remain ture, and if additions are needed, they should relate in use; thirdly, it has to resist and use the effects of in form and scale, and also be less noticeable than climate; and, lastly, a whole team of ‘professionals’ the original material; but, at the same time, being have to collaborate. A professional can be defined identifiable by a skilled observer. Persons who have as a person who contributes artistically, intellectu- insufficient training or experience should not ally or practically to a project. The principal profes- undertake the work. Some problems are, however, sions involved in architectural conservation are unique; and in this case, the conservation architect architects, archaeologists, building economists, should ask for a second opinion. He also has the structural, mechanical and electrical engineers, art right to ask for scientific advice. Due to the irre- historians, materials scientists, crafts persons for placeable nature of cultural property, a conservation each material, building contractors, surveyors, and architect has a heavy load of responsibility. The doc- town planners. It should not be forgotten that the trine of conservation has been encapsulated by the building owner or his representative is also an International Council on Monuments and Sites important collaborator. This list is incomplete, (ICOMOS), in four Charters: because a project may need other specialists in the team such as biologists, geologists, hydrologists, • The Venice Charter (1964) on the basis of all seismologists and even vulcanologists. How does modern conservation one achieve aesthetic harmony with such a com- • The Florence Charter (1981) on gardens and plex and disparate group of professionals? landscapes vii Preface to third edition • Charter for the Conservation of Historic Towns Use values 1987 • Functional • The International Charter for Archaeological • Economic (including tourism) Heritage Management 1990 • Social (also including identity and continuity) • Educational Mention should also be made of the Australia ICO- • Political MOS Burra Charter—for Places of Cultural Significance (revised 1999). These values have to be analysed, and then The first statement of principle, however, was con- synthesized in order to define the ‘significance’ of tained in William Morris’ 1877 ‘Manifesto for the the historic artefact. Some of these values deserve Society for the Protection of Ancient Buildings’ (SPAB) amplification. (see Appendix IV), and this has been, and is still, most Symbolic and spiritual feelings depend on cul- influential in England. Architectural conservation tural awareness. In the West we have largely lost an depends on a thorough study of the building as it understanding of symbolic decoration, and also the stands, followed by any further analytical studies content of classical allusions in painting, now deemed necessary, in order to make a correct diag- understood mainly by art historians. Certain archi- nosis of the structural actions of the said building, tectural forms do, nevertheless, have a spiritual and the causes of its decay. In this way, it is rather message—different forms for different cultures and like the practice of medicine. It is then necessary to religions, and even in supreme cases, such as Hagia consider alternative lines of action. With a multi- Sophia in Istanbul, which has served as a church, a disciplinary team, it is difficult to obtain agreement, mosque, and now a museum, a universal message. as each professional has different objectives, and Spiritual values can come from evidence of past often his training has enclosed an expert’s mind piety, and from the present statement of the monu- with too much specialization. A structural engineer ment and its site, such as a spire reaching to concentrates on stability and safety; an archaeologist heaven, or an ancient temple set on a promontory concentrates