Ship of Theseus Conservation:

Concept of Change in Heritage Architecture Reuse

忒修斯之船:再利用建築遺産中改變的理念

Edward Leung 梁以華

古希臘國王忒修斯的船被他的人民保留了500年,在木板腐爛時便更換直到船。那麼問題來了:這艘還是忒修斯原來的船嗎?這種變化是否被認為是有效的保育?更重要的是適當的建築遺產保育能接受變化嗎?


The Ship of Ancient Greek King Theseus was kept by his people for 500 years, who replaced the planks one at a time as they rotted, until at the end none were the original. The question then is: is this ship still the original? Are such changes considered valid conservation? Or more to the point, can proper architectural heritage conservation accept changes? If yes, to what limit? This article addresses this topic by revisiting the types of reusing heritage architectures in Hong Kong, the reasons for inevitable changes in dealing with these reuse projects, and more importantly, the principles of cultural values and people’s views in regard to changes in heritage conservation. The author attempts to use this well-known philosophical paradox of Ship of Theseus to revisit the dilemma faced by conservation architects, “What principles can guide decisions on changes to the buildings when pursuing reuses of heritage architectures?”

The ship wherein Theseus and the youth of Athens returned had thirty oars, and was preserved by the Athenians down even to the time of Demetrius Phalereus, for they took away the old planks as they decayed, putting in new and stronger timber in their place, insomuch that this ship became a standing example among the philosophers, for the logical question of things that grow; one side holding that the ship remained the same, and the other contending that it was not the same.’¹

Greek historian and writer Plutarch(AD 46 – 119).

King Theseus, as many of us learned in our childhood, was the Greek hero who rescued a group of youths by killing the Minotaur. The citizens of Athens commemorated his glorious victory by preserving and displaying the ship he used for his adventure for the next 500 years, keeping it in good shape by replacing its planks one by one as they rotted. Greek philosophers, from Heraclitus to Plato, debated whether the ship, once all its planks had been replaced, was still the Ship of Theseus. We can ask the same question when it comes to heritage conservation: to what degree can changing an object or building be allowed for the sake of ‘preserving’ it? Is there a point at which conservation becomes reconstruction? Is it possible to come up with an objective and scientific measurement scheme that would satisfy everyone?

Everything changes over time, including the physical environment, and so should our attitudes towards them. Human beings learned painfully in the past century that short-sighted changes can result in unexpected and regrettable effects that we didn’t have the knowledge to predict at the time of such actions. Since we will never be able to predict the future, we instead should aim at acquiring the wisdom necessary to constrain ourselves voluntarily within a cautious approach, avoiding actions that might potentially be difficult to reverse if later found to be in error.

Conservation of a heritage environment, of the natural environment or even of intangible traditions and social networks is a discipline that mature societies exercise to balance the necessity or unavoidability of changes with well-calculated measures that prevent irreversible damage. Australia’s ICOMOS (International Council on Monuments and Sites) advocates that “Conservation … requires a cautious approach of changing as much as necessary but as little as possible”². The ethics of sustainable development call for recognising the necessity of development in every sense, not just in construction and finance, but also in human endeavours such as social welfare, healthcare, education, social justice and cultural activities, while not depriving future generations and neighbouring communities of resources that might become available in the future. This points to thinking of ways of renewing environmental resources or reviving cultural heritage through disciplined change. As English Heritage has written:‘Conservation is the process of Managing Change in ways that will best sustain the (Cultural) Significance of a place in its setting, while recognizing opportunities to reveal or reinforce its (Cultural) Values”³.

Practical scenarios change
Historic buildings can be reused in many ways, not just those narrowly defined by the categorization of use under modern buildings ordinances. Harold Kalman sums this up as: ‘The priority in planning for conservation is to identify a viable and productive use for a historic place… However, the traditional or present use is frequently no longer practical, or because the spatial needs of the traditional uses have changed… A choice must be made as to whether to alter a redundant place to accommodate the changed demands of the traditional use, or whether to re-purpose it for a new use (adaptive reuse)” .Clearly, the concept of reuse for purpose of conservation is far reaching, but would necessarily involve some degree of change.

The professional jargon for change in the context of heritage conservation is intervention, meaning intentional works that are performed to a heritage artefact or building to change its status. International best-practice conservation charters and guidelines recognise different levels of Intervention as valid conservation methods, applicable for different circumstances. The Burra Charter — the international heritage conservation charter currently most frequently used by professionals, particularly in Asia — cites maintenance as the method involving the minimum level of intervention. It further recognises preservation and restoration as valid conservation methods involving slightly higher levels of intervention, while yet higher intervention approaches such as reconstruction or adaptation can also be considered, subject to more vigorous evaluations and weighting the risks of potential damage of historic fabric against the benefit of presenting cultural significance. As is noted in the Burra Charter, ‘Change may be necessary to retain cultural significance but is undesirable where it reduces cultural significance. The amount of change to a place should be guided by the cultural significance of the place and its appropriate interpretation.’

In the field of architectural conservation in Hong Kong, we encounter various types of scenarios, each requiring a different level of intervention. The following paragraphs explain such necessary changes in three scenarios for the purpose of “reuse” of historic sites or buildings, using three cases which the author worked on.

Scenario one: repair or restore. ‘The object of Restoration is to revive the original concept or legibility of the object. Restoration and re-integration of details and features occurs frequently and is based upon respect for original material, original design and authentic documents. In a sense, the cleaning of a building is also a form of restoration, and the replacement of missing decorative elements is another,’ writes Bernard Feilden. Tsing Shan Monastery in Tuen Mun is home to a large terrain of ancient Buddhist grounds dating back to the 5th century. Most of its surviving magnificent Buddhist buildings, dating from the 1920s, had badly deteriorated due to continuous misuse. The top priority of this project was to carry out urgent repairs such as the replacement of timber purlins, fractured bricks, broken roof tiles and decaying timber in order to prevent the collapse of structures. The objective was to allow this ancient Buddhist compound to once again offer religious functions for worshippers and show its architectural glory to visitors. In general, what ordinary people like to see ‘changed’ in projects such as this damaged traditional plaster and ceramic decorations restored to their original condition using traditional materials and crafts. What they rarely see as being ‘‘changed’’, are the such essential modern additions as foundation underpinning, sub-soil drainage, fire services, clean water supply and termite eradication, all of which are essential to keep the relics standing and fit for people’s use.

Scenario two: upgrade and consolidate. Some historic buildings in Hong Kong have retained their historic uses but without being able to meet contemporary standards of operation. In the case of Kowloon Bowling Green Club, built in 1926, what started as a seemingly simple roof repair resulted in the discovery of previously concealed problems and so a replacement with modern facilities. The final scheme of work was preceded by thorough research and investigation to understand the building’s original design and construction. Consolidating its slightly warped structure required strengthening at strategic junctions and a shifting of weight back to its original designated load-path – a task that proved rather more complex than reconstruction.

Scenario three: revitalise or adaptive reuse. This approach requires innovative design able to convert a historic building into one with a new use that suits contemporary society yet respects its heritage context. Exemplifying it is the multi-award-winning project 7 Mallory Street, an ambitious conversion of a row of historic shophouses dating from the 1910s into a modern art and cultural exhibition space with restaurants and shopping units. Our team, with the full support of the client, decided not to re-build the half-collapsed rear part of one row of buildings, but instead to create a public open space with a vertical greenwall and paving and lighting that demarcated the silhouette of the original buildings.

All three cases above demonstrate that good practice conservation does not solely tackle the physical retention of existing materials and appearance but rather looks at enhancing the appreciation of cultural heritage values and strengthening the association of historic buildings with the public and users. In all three, conservation has resulted less in keeping physical remains and more on emphasising how to ‘celebrate associations between people and a place, … (and to) respect meanings of a place to people; … (and to) explore opportunities to interpret these; … (it is because) retention of associations or meanings may also be conservation. 

Rethinking the theory of change in conservation

Let us return to our Ship of Theseus and attempt to establish some guidelines on how much can be justified for conservation projects. Modern philosophers have developed “four-dimensional meta-physics” (sometimes known as worm theory or stage theory). Let us suppose the Ship of Theseus had 500 old planks to begin with when the King sailed back to Athens, and the people replaced one plank per year. The philosophical question is whether the ship after its first year, with 499 of its original planks, could still be regarded as that in which Theseus returned home, and a year later? And 499 years later? Perhaps instead we should think that the ship had not existed at any single time, except as a four-dimensional entity spanning 500 years. Suppose King Theseus lived for another 500 years, regularly maintaining his boat with care, with no regard as to which planks he replaced, recalling only his battle with the Minotaur in his annual ceremonial sail around the harbour, then would the boat still have been the Ship of Theseus? This points to the idea that heritage conservation could be less about an object and more about retaining and sustaining the cultural association between an object and people. So should we practice heritage conservation in the same light – considering ourselves custodians of a structure that we must maintain and treasure for all future generations to use and admire? To conclude, I would like to recall a statement by ICOMOS: ‘Architectural Heritage possesses an Intrinsic Value independently of its initial role and significance, which enables it to adapt itself to a Changing social, economic, political, and Cultural Context.”

Edward Leung is an architect who specializes in altering historic buildings. He teaches architectural conservation and is former HKIA former Heritage and Conservation Committee chair.
梁以華是一名建築師,擅長改造歷史建築, 並教授建築遺產保育。他亦曾任香港建築師學會古蹟及文物保育委員會主席。


¹ Levin, N. (Ed). “Ancient Philosophy Reader: An Open Educational Resource”, N.G.E. Far Press, 2018, ch 1.
² Australia ICOMOS, “Burra Charter”, 1981, Article 3.1.
³ English Heritage, “Conservation Principles, Principles, Policies and Guidance for the Sustainable Management of the Historic Environment” 2008 Clause 4.2I.
⁴ Kalman, Harold, Heritage Planning – Principles and Progress, New York, Routledge, 2014, p236.
⁵ Australia ICOMOS, “Burra Charter”, 1981, Article 15.1.
⁶ Feilden, Bernard, “Conservation of Historic Buildings”, Butterworth Heinemann, Oxford, 1982, p9I.
⁷ Australia ICOMOS, “Burra Charter”, 1981, Articles 14 & 24.
⁸ ICOMOS General Assembly Budapest, 1972, Preface.

Adaptive Reuse at 7 Mallory Street, Wanchai (Credit URA).

Tsing Shan Monastery (Credit Richard Wong, 2011. https://www.flickr.com/photos/61422138@N04/5721243774/in/photo stream/).

Guided tour at 7 Mallory Street, Wanchai (by author).

Adaptive Reuse at 7 Mallory Street, Wanchai.
 Section showing programme (Credit URA).