Windows

History, Repair and Conservation

Editors: Michael Tutton and Elizabeth Hirst

Consultant: Hentie Louw

Managing Editor: Jill Pearce

Chapter One

Introduction

Elizabeth Hirst

The window has a long and fascinating history. It has evolved in response to the availability of resources, developments in design and technology, and the demands of those who use them. At once functional and aesthetic, the window must keep out the weather, provide ventilation, prevent intruders and buffer sound. Windows are also integral to the appearance of buildings, reflecting the practice and taste of particular regions or periods. The window cannot be seen in isolation from the building fabric in which it is set.

Windows presents, for the first time, an encyclopaedic treatment of the history and conservation of windows. Bringing together the work of leading historians and the practical knowledge of Britain’s principal experts on fenestration, this book is accessible to amateur and professional alike. It is remarkable that an object as functional as the historic window should have such a rich history, covering so many diverse disciplines.

This project was originally conceived by Donhead in 1995, prompted by a need to broaden understanding of the significance and decorative value of traditional windows, at a time when functionality and misplaced views regarding energy efficiency were fast leading to the loss of historic fenestration, and with it the original and cohesive appearance of whole streets. The resulting book not only provides the reader with key information on the history of windows, it also presents a clear and methodical approach to their repair and preservation, rather than replacement.

All aspects of the historic window, within its architectural setting, are treated in detail, including the history, technology and conservation of this familiar but surprisingly complex feature. There is also a review of past and present legislation on the form and performance of the window, from requirements reflecting the modern concern for energy efficiency to the preservation of the historic window within designated conservation areas. These issues are too diverse to be covered by one specialist alone. The wide-ranging contents of Windows, written by a team of experts, therefore reflect the multi-disciplinary approach often required as part of a well-considered conservation strategy.

A study of the historic window, particularly within the context of conservation, must inevitability include a consideration of decay. Weathering, wear and tear, faulty technology, a lack of maintenance, vandalism, inappropriate repairs, adverse environmental conditions, mould and insect infestation can all contribute to a clear reduction in efficiency. Surveyors, structural engineers, craftsmen and conservators describe their approach to assessing, maintaining and repairing the window, both as a complete unit in its own right and as an object composed of materials such as stone, wood, metal, glass and paint. They go on to provide practical and specialist advice for maintenance and repair. There is also a discussion of how general principles of conservation apply to a window, allowing sustainable repair solutions based on detailed understanding, with any intervention carefully evaluated and justified.

A historic window may be protected by the listing of a building or within a general conservation plan in which its significance is highlighted. There are, however, many historic windows not protected by legislation. It is these that are most at risk from inappropriate repair or replacement due to misconceived attitudes. Inappropriate repairs may lead to further deterioration and eventual replacement, possibly with a contemporary or pastiche design in uPVC.

Home Information Packs (HIPs) are also likely to encourage replacement, with energy efficiency high on the agenda as homeowners are advised to modify their windows to reduce the carbon emissions. Developments in design technology have allowed modern windows to reach ever-greater performance standards. The pursuit of such standards in a historic structure may, however, be more appropriately achieved by traditional methods such as the use of heavy curtains rather than the introduction of double-glazing.

The first part of the book deals with the history and development of the window. The evolution of the window is placed in a historic context by Hentie Louw who explores fenestration from the time of Henry VIII to the twentieth century, considering the technical and artistic influences on its development. He also traces the decline and neglect of the traditional British window, warning of the danger of it becoming obsolete in the face of modernization. Treve Rosoman then provides a guide to the development of window furniture, describing the various types of handles, hinges, pulleys and stays to be found in a historic casement or sash window. This is illustrated by photographs and illustrations from nineteenth- and early twentieth-century sales brochures, which provide a fascinating insight into how windows furniture evolved. David Martlew traces the development of glass and glassmaking, from the time of Pliney to the early twentieth century. He describes the types of historic glass to be found in historic windows and explains the technology behind their manufacture. Charles Brooking, whose lifelong fascination with the historic window has resulted in the many salvaged examples preserved in the Brooking Collection at the University of Greenwich, provides an illustrated glossary chapter to assist in the identification of both conventional and rare window types.

The second part of the book starts with the often complex subject of heritage legislation. Bob Kindred argues that one of the most significant contributions to a historic building’s interest and authenticity is the retention rather than the alteration or replacement, of the original windows. He also touches upon various policies and initiatives in the past 40 years aimed at retaining and conserving historic windows, and considers several issues relating to listed buildings and conservation areas. Michael Tutton and Robert Thorniley-Walker advise on the subject of surveying, emphasizing the need for the condition of the window and adjacent building fabric to be thoroughly recorded prior to any practical works. This, they stress, will provide the basis for treatment recommendations and act as a datum level against which any further deterioration, intervention or monitoring can be measured. Robert Thorniley-Walker also considers structural issues in terms of the complexity of a window and its vulnerability to forces of decay. He outlines appropriate methods of repair in the light of current conservation philosophy. Finally, Mike Parrett examines the value of our historic windows within the context of the complete building envelope, highlighting the current stringent performance standards required from a contemporary window in terms of ventilation and heat retention, standards which may not always be possible or appropriate for older windows.

Historically, windows have been fashioned from wood, stone or metal, materials that were often sourced locally. The unique characteristics of each are discussed in the third part of the book. The use of timber is reviewed by Alan Lamb, who describes the varieties of wood and joinery techniques that were traditionally used to make sash and casement windows. His study includes a guide to the most common types of deterioration in a timber window together with recommendations for maintenance and repair. The subject of decay is expanded on by Jagjit Singh, who describes the impact of water, adverse environmental conditions and biological organisms such as fungi, rot, moulds and insects on the long-term stability of the historic timber window. He emphasizes the importance of good maintenance, and describes other factors that may affect the condition of a window, such as faults in the original design or materials used in its manufacture, as well as the general condition of the building envelope and the extent to which the window is exposed to harsh weather conditions. Eleni Makri and Rupert Harris present an original and thorough introduction to the materials used for the manufacture of metal windows. These ranged from wrought and cast iron, to mild steel aluminium to the more decorative copper, brass and bronze. The development of the windows particular to each metal is described, together with the individual conservation issues and strategies of repair to each, in light of the ever-present issue of replacement versus repair. In a detailed but practical guide to appropriate conservation strategies for the decayed masonry window Graham Abrey emphasizes the importance of using appropriate materials and skilled craftsmanship in any campaign of repair. Ruth Cooke then outlines the ancient craft of leaded glazing, with its use of stained and painted glass, giving a description of common types of deterioration, preventive conservation and the essential role of the condition survey. Finally, Karen Morrissey looks at the traditional paint finishes found on the historic windows, and describes the analytical methods currently used to identify original coatings. These methods can frequently offer an insight into the date and history of a window, together with intriguing clues as to how a building may originally have appeared.

The collective impression left by the book is one of wonder that such a familiar device as the window can have so elaborate a history, yet be so vulnerable to decay, be it at the hands of nature and neglect or whims of changing fashion. Windows brings together the most up-to-date methods of surveying, maintaining, conserving and repairing our historic windows. It is both a fascinating history and a practical manual full of helpful tips. The publishers, editors and contributors all hope that it will go some way to preserving one of the most valuable facets of our heritage buildings.

Elizabeth Hirst ACR, FRSA