Journal of Architectural Conservation

Volume 15 Number 3 November 2009


Editorial Professor Peter Swallow

Conservation of Historical Observatories in the UK and Ireland Elliss Sharpe

The Monument to the Great Fire of London: An Investigation of the Verticality of the Monument and the Re-securing of the Flaming Orb Judy Allen

Historic Fabric vs. Design Intent: Authenticity and Preservation of Modern Architecture at Frank Lloyd Wright’s Guggenheim Museum Angel Ayon

Diagnosing Defects in Lime-Based Materials  Jeremy Ingham

Bats and Historic Buildings: The Importance of Making Informed Decisions Jonathan Howard




Read the Editorial by Professor Peter Swallow MBE



Abstracts and author information


Conservation of Historical Observatories in the UK and Ireland

Elliss Sharpe


Historic buildings dedicated to scientific research are rarely mentioned in architectural heritage literature, or are relegated to novelty interest status. However, astronomy is one of the few sciences to possess unique, purpose-built and, in many cases, easily recognizable buildings. They have been central to significant advances in navigation, accurate timekeeping and refining the calendar; all in addition to their obvious use for wider investigation of the cosmos.

There are many observatory buildings in the UK associated with insti­tutions or historic figures. There are also historic monuments that most would not recognize as observatories, but which have been used for astronomical observation or specifically built for the purpose. This paper seeks to heighten awareness of observatories in this UNESCO International Year of Astronomy 2009, by discussing their historic development, their relative rarity and, through examples, the conservation status of some of these highly specialized buildings, which continue to survive even though modern astronomical observation is now performed elsewhere.



Elliss Sharpe

Elliss Sharpe has worked in the construction industry in management and consultant roles on a variety of projects. Following experience of historic building conservation on prominent buildings in London, including Horseguards Parade and the Royal Naval College, Greenwich, he undertook an MSc Degree in Conservation of the Historic Environment, University of Reading. He is an amateur astronomer, past secretary of the Loughton Astronomical Society, member of the Society for the History of Astronomy, and Fellow of the Royal Astronomical Society. He is writing a book, Watch-Towers to the Cosmos, based on his MSc dissertation on historic observatories of the UK and Ireland



The Monument to the Great Fire of London

An Investigation of the Verticality of the Monument and the Re-securing of the Flaming Orb

Judy Allen


At the very top of the 202-ft-high Monument to the Great Fire of London, c. 1677, a substantial armature secures the gilded copper flaming orb down to the Portland stonework of the column. During the 2007–09 Monument major repair contract, the armature was found to be tilting over, crushing stonework and causing concern over the stability of the flaming orb. The general movement of the Monument over the years is discussed here together with the specific movement of the armature and consequent damage to the historic fabric. Reasons for the tilting are offered along with a description of the approach taken to resist further movement until the next inspection of the exterior in about 80 years’ time, the average frequency of scaffolding the Monument.



Judy Allen

Judy Allen is an Associate at Julian Harrap Architects, historic building specialists, and has been with the practice for 21 years, working as project architect for many Grade I-listed buildings including Sir John Soane’s Museum, the Farnborough wind tunnels, St Clement Eastcheap, Cliveden Estate and Headstone Manor.



Historic Fabric vs. Design Intent

Authenticity and Preservation of Modern Architecture at Frank Lloyd Wright’s Guggenheim Museum

Angel Ayon


This paper attempts to address the dichotomy between preservation of historic fabric and the original design intent, which may arise during interventions on buildings from the Modern period. It presents intervention principles developed for recent preservation work at Frank Lloyd Wright’s Solomon R. Guggenheim Museum in New York, and outlines how these principles were used to address four specific design challenges posed by Wright’s masterpiece. By addressing structural repairs, rain protection, fenestration upgrade and exterior colour issues, the paper shows how, during the Guggenheim project, priority was assigned to the design intent in some cases, to the historic building fabric in others, or indeed to neither factor. It explores the concept of authenticity and expands its application in the context of the preservation of Modern architecture by considering issues of craftsmanship and mass production, integrity and durability, systems performance and conservation state, original expression and contributing changes.



Angel Ayón

Angel Ayón, LEED AP, specializes in documentation, conditions assessment, repair and adaptive reuse of historic buildings and sites. He was the Project Architect for the Exterior Restoration and Building Enhancement of the Guggenheim Museum.* Mr Ayón holds a professional degree in Architecture and an MSc in Conservation and Rehabilitation of the Built Heritage from the Polytechnic Institute in Havana, Cuba, and a Post-Graduate Certificate in Conservation of Historic Buildings and Archaeological Sites from Columbia University in New York.

*The Exterior Restoration and Building Enhancement of the Solomon R. Guggenheim Museum was designed by preservation architects WASA/Studio A; structural engi­neers Robert Silman Associates PC; architectural conservators Integrated Conserva­tion Resources Inc.; exterior envelope consultant William B. Rose & Associates; and M/E/P engineers Atkinson Koven Feinberg Engineers, LLP among other consultants and owner’s representatives. The opinions included in this article are the author’s and do not necessarily represent those of other members of the design team.




Diagnosing Defects in Lime-Based Materials

Jeremy Ingham


This paper describes the techniques available to ensure correct diagnosis of defects in lime-based construction materials. It commences with a discussion of the types of defects and their causes. Details of the techniques used for investi­gation of defects and their diagnosis follow. In addition, a summary of the types of repair that should be used for each defect is provided. The paper includes examples from conservation projects for a variety of historic structures.



Jeremy Ingham

Jeremy Ingham is a Senior Materials Engineer with the Asset Management and Engineering Skill Group of Halcrow Group Limited. He provides consultancy and investigation services for construction and conservation projects worldwide, involving materials technology, forensic engineering and asset management planning. He has fifteen years’ experience of historic structures and traditional construction materials, and of providing condition surveys, laboratory testing, selection of materials and specification of repairs. He is an expert microscopist and author of the book Geomaterials Under the Microscope – A Colour Guide.



Bats and Historic Buildings

The Importance of Making Informed Decisions

Jonathan Howard


Those responsible for historic buildings and structures often have to manage a diverse range of demands and expectations placed on them by various stake­holders who may not be equally supportive of efforts to conserve the historic significance of the building. However, one very rare and important group of stakeholders, with the law behind them, like the building just the way it is. The seventeen species of bats resident in Britain and Ireland and their roost sites receive total protection under domestic and EU law. All have been recorded in historic built structures, and some rely on roost sites in historic buildings for breeding. This article outlines the importance of historic buildings as bat habi­tats and how crucial it is that we use the same sensitivity and rigour to reach informed decisions which impact on bats as we would for built heritage.


Jonathan Howard

Jonathan worked for the National Trust in the UK for five and half years, first as a House Steward at Snowshill Manor and as the Building Research Assistant at the Head Office. During the course of this work he co-authored Managing Bats in Traditional Buildings. Since February 2007 he has worked for the New Zealand Historic Places Trust as a Heritage Advisor for building conservation for the Otago/Southland office.



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