Journal of Architectural Conservation
Volume 10 Number 3 November 2004
Hot Lime Mortars A. Forster
Asmara, Eritrea: The Balanced Approach to Conservation and Development in a Historic City Centre Dennis Rodwell
Saving Structures D. Yeomans
The Building Department of the National Trust R. Cullen
Disability Access to Buildings and Monuments Lisa Foster
Obituary: Martin Weaver Hugh Miller
Making the right judgement
Conservation is and will hopefully remain a judgement-based discipline, but with this comes the responsibility for basing such judgements on best available knowledge. This process of tempering opinion with fact lies at the heart of what provides architectural conservation with some of its most stimulating intellectual challenges.
Working on the premise that if you do not look for something you will not find it, the papers in this issue of the Journal concern themselves with the discovery and application of new knowledge, together with the reappraisal of existing wisdom.
Saving Structures by Dr David Yeomans provides a summary of the recent ICOMOS Recommendations for the Analysis, Conservation and Structural Restoration of Architectural Heritage. Comprising general principles and specific guidelines, this document stresses the importance of bringing together a project team and with it the early appointment of a conservation engineer. The appointment and responsibilities of the engineer are considered by Dr Yeomans, as too are the implications for education and training.
The subject of lime is never far from the minds of those dealing with historic buildings. Hot-Lime Mortars: A Current Perspective by Dr Alan Forster of the Scottish Lime Centre Trust offers an overview of current thinking on the history and use of hot-mixed mortars. This preliminary investigation raises questions regarding the characteristics and performance of such mortars, with the aim of stimulating debate and further research.
In Asmara: Conservation and Development in a Historic City, Dennis Rodwell writes about one of the world's youngest and poorest countries, Eritrea, and what has been described as Africa's 'Secret Modernist City'. This paper considers the urban and building conservation issues being faced by those concerned with the historic centre of Asmara, and the development of an integrated strategic plan for this expanding city.
Closer to home, Rory Cullen and Nikita Hooper present a summary of the work undertaken by the Building Department of the National Trust. With over 25,000 buildings in its care, embracing both polite and vernacular architecture, the Trust's responsibilities for repair, maintenance, and conservation are complex and wide-ranging. This paper looks at three differing projects to illustrate the approaches taken by the Building Department in its work.
Progressive Access: Unique Solutions for Disability Access to Buildings and Monuments by Lisa Foster provides an important and timely reminder of responsibilities under the Disability Discrimination Act. Considering non-stepped access into and within historic buildings, this paper uses a number of studies to show how access solutions have to be designed with the opportunities and limitations of building or site in mind. Access planning and access statements are considered in relation to current regulation and guidance, but with the overall message that there is no standard access solution.
A Current Perspective
Analytical and documentary evidence indicates that hot-lime mortars were used in traditional construction. These are defined as mortars manufactured by mixing quicklime and sand, rather than the current and more commonly adopted method of combining previously slaked lime with sand. Hot-lime mortars are again being used and are perceived to have advantages over cold-manufactured mortars. Little is understood, however, regarding the physical and chemical performance of hot-lime mortars. This paper highlights current views on the subject and considers why hot-mixed mortars appear to offer better performance than alternative lime mortars. The potential for altered hydraulic properties, bond characteristics between the lime/aggregate interface, pore-structure development, and micro-structure performance are assessed, although it is stressed that this is only a preliminary investigation aimed at stimulating debate and further research.
Alan M. Forster BSc (Hons), PhD, SPAB Lethaby Scholar
Dr Alan Forster qualified as a building surveyor and gained his PhD from Heriot-Watt University in 2002 for his work on the hydraulicity and water-vapour permeability of lime-based mortars. He was awarded a travelling scholarship with the Society for the Protection of Ancient Buildings (SPAB) in 2001and is currently employed by the Scottish Lime Centre Trust as a building surveyor/training manager.
The Building Department of the National Trust
Rory Cullen and Nikita Hooper
The National Trust was founded in the late nineteenth century on the fundamental principles of providing people with opportunities for recreation, both physical and mental, through the preservation of places of natural beauty or historic interest, and safeguarding these places forever. The Trust's collection of buildings now numbers over 25,000. The various forms and styles of architecture represented present numerous challenges to the Building Department of the Trust, which is responsible for the repair, maintenance, and conservation of their fabric. The work carried out by the department can vary from minor maintenance repairs to major structural conservation projects. Whatever the size of task undertaken, work is always carried out on the basis that it must contribute to the preservation of the building so that future generations may both enjoy it and learn from it. The work of the department is demonstrated through three case studies, illustrating the approaches that have to be employed whilst undertaking work on all buildings in the Trust's care.
Rory Cullen MSc, FCIB, IHBC
Rory Cullen is Head of Building at the National Trust. He has an MSc in building conservation, is a Fellow of the Chartered Institute of Building, and a member of the Institute of Historic Building Conservation.
Nikita Hooper is a member of the National Trust's Central Building Department. He has a background in fine art and antiques, and is currently reading for a BA degree in history and history of art.
Conservation and Development in a Historic City
Eritrea is one of the world's youngest and poorest countries. Cultural heritage programmes are at the forefront of its affirmation of national identity and central to its perception of sustainable development.
Asmara, planned by the Italians as their colonial capital for the region, has been described as 'Africa's Secret Modernist City'. The city centre is host to an exceptional range of late nineteenth- to early twentieth-century architectural styles, including a number of iconic buildings from the 1930s. It has remained largely untouched since the 1940s.
This paper outlines the national context. It aims to summarize the key urban and building conservation issues facing the historic centre of Asmara, and how these are being addressed both within themselves and in the context of the integrated strategic plan for the expanding city. The plan's overall approach is one that seeks to achieve a balance between the demands of conservation and development, supporting traditional small-scale mixed uses and the human culture that goes with them in the historic core, whilst encouraging the siting of large-scale new developments in locations that complement rather than conflict with the established urban fabric and architectural heritage.
Although the geographical and historical context is very specific, the approach that is being pursued in Asmara is one that offers lessons for the sound practice of urban conservation elsewhere in the developing and developed world.
Dennis Rodwell MA, DipArch(Cantab), DipFrench(Open), RIBA, FRIAS, FSA Scot, FRSA, IHBC
Dennis Rodwell is based in south-east Scotland. He practises as a consultant architect-planner, working internationally in the field of cultural heritage, and focusing on the promotion and achievement of best practice in the management of historic cities and conservation of historic buildings.
The analysis of historic structures is often carried out using similar methods to those employed for new construction, while recommendations for repair may be framed to comply with modern design codes. Both are often inappropriate. A scientific committee of ICOMOS has recently drafted a set of recommendations that point out the dangers to the historic fabric of adopting this kind of approach, while also describing more appropriate methods. This paper outlines the background to the drafting of these recommendations and reviews their main points.
David Yeomans BSc (Eng), PhD, AIWSc
David Yeomans is a Senior Research Fellow of the Liverpool School of Architecture and Secretary of the International Scientific Committee for the Analysis and Restoration of Structures of Architectural Heritage (ISCARSAH). He has taught both structural design and building conservation, and practises as an engineer specializing in the repair of historic timber structures.
Unique Solutions for Disability Access to Historic Buildings and Monuments
In the ten years since the provisions of the Disability Discrimination Act 1995 (the DDA) were introduced and adopted, there have been significant examples of adaptation for the non-stepped access into and within historic buildings. The range and types of solutions discussed in this paper reflect the inherent opportunities and limitation of each building or site, and illustrate that there is no single statutory right answer.
What is 'reasonable accommodation' under the provisions of the DDA for service providers, education providers, and employers must, by definition, be unique to the building or site, and derive from the proposed or existing use, the existing features and type of building, and, importantly, the exercise of judgement by the conservation professionals involved in the decision-making process. This flexibility is acknowledged for the first time in the newly revised Approved Document M of the Building Regulations, which provides for Access Statements to be submitted in the planning context to enable building owners to explain their preferred approach to disabled access and why it may vary from the standard guidance. The access planning process is outlined in the revised English Heritage guidance note Easy Access to Historic Buildings, published in July 2004.
Lisa Foster BA, MA, Juris Doct (Law)
Lisa Foster trained and practised as a lawyer before taking an MA in building conservation at the University of York in 1993. Her book, Access to the Historic Environment, published by Donhead Publishing in 1996, is unique in the access field. Lisa Foster specializes in advising on disability access in the historic environment.
Donhead Publishing 2013